Navajo Nation v. Department of the Interior, et al

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FILED OPINION (RONALD M. GOULD, MARSHA S. BERZON and MARVIN J. GARBIS) AFFIRMED IN PART, REVERSED IN PART AND REMANDED. Judge: MSB Authoring FILED AND ENTERED JUDGMENT. [10675851]

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Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 1 of 1200 ior Inter 17 0 f the pt. o er 29, 2 De v. mb ation on Nove jo N Nava archived in cited 16864, 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 2 of 1200 TABLE OF CONTENTS S.1 INTRODUCTION AND BACKGROUND.........................................................................1 S.1.1 INTRODUCTION ................................................................................................. 1 S.1.2 PROPOSED FEDERAL ACTION ........................................................................ 4 S.1.3 S.1.3.1 S.1.3.2 BACKGROUND ................................................................................................... 4 Long-Range Operating Criteria ................................................................ 5 Annual Operating Plan .............................................................................6 S.1.4 PURPOSE AND NEED FOR ACTION................................................................ 7 S.1.5 RELATIONSHIP TO UNITED STATES–MEXICO WATER TREATY ........... 8 S.1.6 RELATED AND ONGOING ACTIONS.............................................................. 8 S.1.6.1 California’s Colorado River Water Use Plan ........................................... 8 S.1.6.1.1 Imperial Irrigation District/San Diego County Water Authority Water Transfer.......................................................................................... 9 S.1.6.1.2 All-American and Coachella Canal Lining Projects .............................. 10 S.1.6.2 Glen Canyon Dam Operations................................................................10 ior Inter 17 S.1.6.2.1 Adaptive Management Program............................................................. 11 the t. of r 29, 20 pand Beach/Habitat-Maintenance S.1.6.2.2 Beach/Habitat-Building Flows . De be Flows ...................................................................................................... 11 ion v Novem at on ajo N S.1.6.2.3 Temperature Control at Glen Canyon Dam............................................ 12 NavRelated hivedBiological and Conference Opinion on in arc to the S.1.6.3 cited Actions64, 8Colorado River Operations and Maintenance ............................. 12 Lower -16 o. 14 N S.1.6.4 Lower Colorado River Multi-Species Conservation Program ............... 13 S.1.6.5 Secretarial Implementation Agreement Related to California’s Colorado River Water Use Plan ............................................................. 13 S.1.6.6 Offstream Storage of Colorado River Water and Development and Release of Intentionally Created Unused Apportionment in the Lower Division States ............................................................................ 14 S.2 ALTERNATIVES .............................................................................................................. 14 S.2.1 S.2.1.1 S.2.1.2 DEVELOPMENT OF ALTERNATIVES ........................................................... 14 Origins of California, Six States and Basin States Alternatives............. 14 Utilization of Proposals from Basin States............................................. 15 S.2.2 DESCRIPTION OF ALTERNATIVES............................................................... 16 S.2.2.1 No Action Alternative and Baseline Conditions ....................................16 S.2.2.1.1 Approach to Surplus Water Determination ............................................ 16 S.2.2.1.2 70R Baseline Surplus Triggers ............................................................... 16 S.2.2.2 Basin States Alternative (Preferred Alternative) ....................................17 S.2.2.2.1 Approach to Surplus Water Determination ............................................ 17 S.2.2.2.2 Basin States Alternative Surplus Triggers..............................................18 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 3 of 1200 TABLE OF CONTENTS S.2.2.3 S.2.2.3.1 S.2.2.3.2 S.2.2.4 S.2.2.4.1 S.2.2.4.2 S.2.2.5 S.2.2.5.1 S.2.2.5.2 S.2.2.6 S.2.2.6.1 S.2.2.6.2 Flood Control Alternative....................................................................... 18 Approach to Surplus Water Determination ............................................ 18 Flood Control Alternative Surplus Triggers........................................... 18 Six States Alternative ............................................................................. 18 Approach to Surplus Water Determination ............................................ 18 Six States Alternative Surplus Triggers.................................................. 19 California Alternative .............................................................................19 Approach to Surplus Water Determination ............................................ 19 California Alternative Surplus Triggers ................................................. 19 Shortage Protection Alternative.............................................................. 20 Approach to Surplus Water Determination ............................................ 20 Shortage Protection Alternative Surplus Triggers.................................. 20 S.3 SUMMARY OF ENVIRONMENTAL CONSEQUENCES .............................................20 S.3.1 USE OF MODELING TO IDENTIFY POTENTIAL FUTURE COLORADO RIVER System Conditions.................................................................................. 20 S.3.2 BASELINE CONDITIONS................................................................................. 20 S.3.3 IMPACT DETERMINATION APPROACH ......................................................21 erior S.3.4 S.3.5 S.3.6 e Int Dep mber 2 POTENTIALLY AFFECTED AREA ................................................................. 21 n v. e Natio d on Nov ajoSURPLUS ALTERNATIVES TO BASELINE COMPARISONvOF Na hive d in .....................................................................................................22 , arc CONDITIONS 64 cite 168 Effects on Reservoir Surface Elevations and River Flows.....................22 14No. Summary of Environmental Impacts...................................................... 24 17 th PERIOD OF ANALYSIS ....................................................................................21 t. of 9, 20 S.3.6.1 S.3.6.2 S.3.6.3 S.3.6.3.1 S.3.6.3.2 S.3.6.3.3 S.3.6.3.4 S.3.6.3.5 S.3.6.3.6 S.3.6.3.7 Environmental Commitments.................................................................24 Water Quality ......................................................................................... 25 Riverflow Issues .....................................................................................25 Aquatic Resources ..................................................................................25 Special-Status Species ............................................................................26 Recreation............................................................................................... 26 Cultural Resources..................................................................................26 Transboundary Impacts ..........................................................................26 S.4 OTHER NEPA CONSIDERATIONS................................................................................ 27 S.4.1 CUMULATIVE IMPACTS................................................................................. 27 S.4.2 RELATIONSHIP BETWEEN SHORT-TERM USES OF THE ENVIRONMENT AND Long-Term Productivity......................................................................... 28 S.4.3 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES ...................................................................................................... 28 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS ii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 4 of 1200 TABLE OF CONTENTS S.5 CONSULTATION AND COORDINATION....................................................................29 S.5.1 S.5.1.1 S.5.1.2 GENERAL PUBLIC INVOLVEMENT ACTIVITIES....................................... 29 Project Scoping....................................................................................... 29 Public Review of DEIS .......................................................................... 30 S.5.2 S.5.2.1 S.5.2.2 FEDERAL AGENCY COORDINATION .......................................................... 31 National Park Service ............................................................................. 31 U.S. Section of the International Boundary and Water Commission............................................................................................ 31 U.S. Bureau of Indian Affairs................................................................. 31 U.S. Fish and Wildlife Service Including Endangered Species Act Compliance............................................................................................. 31 National Marine Fisheries Service ......................................................... 33 National Historic Preservation Act Compliance ....................................33 S.5.2.3 S.5.2.4 S.5.2.5 S.5.2.6 S.5.3 TRIBAL CONSULTATION ...............................................................................34 S.5.4 STATE AND LOCAL WATER AND POWER AGENCIES COORDINATION ............................................................................................... 34 S.5.5 NON-GOVERNMENTAL ORGANIZATIONS COORDINATION .................35 S.5.6 S.5.7 S.5.8 erior t. of r 29, 20 SUMMARY OF COORDINATION ep CONTACTS .............................................36 v. D mbe ation on Nove FEDERAL REGISTER NOTICES .......................................................................36 jo N Nava archived in cited 16864, 14No. nt MEXICO CONSULTATION .............................................................................. 36 17 the I COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS iii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 5 of 1200 EXECUTIVE SUMMARY COLORADO RIVER INTERIM SURPLUS CRITERIA FINAL ENVIRONMENTAL IMPACT STATEMENT S.1 INTRODUCTION AND BACKGROUND S.1.1 INTRODUCTION The Secretary of the United States Department of the Interior (Secretary), acting through the United States Bureau of Reclamation (Reclamation), is considering the adoption of specific interim criteria under which surplus water conditions may be declared in the lower Colorado River Basin (see Map S-1) during a 15-year period that would extend through 2016. The Secretary is vested with the responsibility of managing the mainstream waters of the lower Colorado River pursuant to applicable federal law. This responsibility is carried out consistent with a collection of documents known as the Law of the River, ior which includes a combination of federal and state statutes, interstate compacts, court Inter 17 decisions and decrees, an international treaty, contracts of the Secretary, operating with the 20 ept. ber 29, criteria, regulations and administrative decisions. v. D m n e Natio d on Nov ajo management objectives are to: The long-term Colorado River systemhive Nav d in 64, arc cite 8 • Minimize 14-16 . flood damages from river flows; No • Release water only in accordance with the 1964 Decree in Arizona v. California (Decree); • Protect and enhance the environmental resources of the basin; • Provide reliable delivery of water for beneficial consumptive use; • Increase flexibility of water deliveries under a complex allocation system; • Encourage efficient use of renewable water supplies; • Minimize curtailment to users who depend on such supplies; and • Consider power generation needs. As the agency that is designated to act on the Secretary’s behalf with respect to these matters, Reclamation is the Lead Federal Agency for the purposes of National Environmental Policy Act of 1969 (NEPA) compliance for the development and implementation of the proposed interim surplus criteria. The National Park Service (NPS) and the United States Section of the International Boundary and Water COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 6 of 1200 EXECUTIVE SUMMARY Commission (USIBWC) are cooperating agencies for purposes of assisting with the environmental analysis. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 7 of 1200 EXECUTIVE SUMMARY Map S-1 Colorado River Drainage Basin ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 8 of 1200 EXECUTIVE SUMMARY A Final Environmental Impact Statement (FEIS), of which this document is a summary, has been prepared pursuant to NEPA, as amended, and the Council on Environmental Quality (CEQ) Regulations for Implementing the Procedural Provisions of NEPA (40 Code of Federal Regulations [CFR] Parts 1500 through 1508). The FEIS has been prepared to address the formulation and evaluation of specific interim surplus criteria and to identify the potential environmental effects of implementing such criteria. The FEIS addresses the environmental issues associated with, and analyzes the environmental consequences of, various alternatives for specific interim surplus criteria. The alternatives addressed in the FEIS are those Reclamation has determined would meet the purpose and need for the federal action and represent a broad range of the most reasonable alternatives. In addition to this Summary, the FEIS contains three separate volumes. Volume I describes the proposed action, the alternatives considered, the analysis of potential effects of interim surplus criteria on Colorado River operation and associated resources, and environmental commitments associated with the action alternatives. Volume II contains attachments that are comprised of documents and other supporting material that provide detailed historical background and/or technical information concerning this proposed action. Volume III contains reproductions of comment letters from the public resulting from the public review of the Draft Environmental Impacterior t Statement (DEIS) he In 2017 and Reclamation’s responses to the comments received.of t , 9 pt. . De ember 2 nv S.1.2 PROPOSED FEDERAL ACTION atio Nov ajo N ived on Nav The proposed federal action is 4, arch d in 6 the adoption of specific interim surplus criteria pursuant cite the 68 to Article III(3)(b) of 4-1Criteria for Coordinated Long-Range Operation of the 1 Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of No. September 30, 1968 (Long-Range Operating Criteria [LROC]). The interim surplus criteria would be used annually to determine the conditions under which the Secretary may declare the availability of surplus water for use within the states of Arizona, California and Nevada. The criteria must be consistent with both the Decree entered by the United States Supreme Court in 1964 in the case of Arizona v. California and the LROC. The interim surplus criteria would remain in effect for determinations made through calendar year 2015 regarding the availability of surplus water through calendar year 2016, subject to five-year reviews conducted concurrently with LROC reviews, and would be applied each year as part of the Annual Operating Plan (AOP). S.1.3 BACKGROUND Pursuant to Article II(B)2 of the Decree, if there exists sufficient water available in a single year for pumping or release from Lake Mead to satisfy annual consumptive use in the states of California, Nevada and Arizona in excess of 7.5 million acre-feet (maf), such water may be determined by the Secretary to be available as surplus water. The Secretary is authorized to determine the conditions upon which such water may be made available. The Colorado River Basin Project Act of 1968 (CRBPA) directs the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 9 of 1200 EXECUTIVE SUMMARY Secretary to adopt criteria for coordinated long-range operation of reservoirs on the Colorado River in order to comply with and carry out the provisions of the Colorado River Compact of 1922 (Compact), the Colorado River Storage Project Act of 1956 (CRSPA), the Boulder Canyon Project Act of 1928 (BCPA) and the United States-Mexico Water Treaty of 1944 (Treaty). These criteria are the LROC, discussed further below. The Secretary sponsors a formal review of the LROC every five years. The LROC provide that the Secretary will determine the extent to which the reasonable consumptive use requirements of mainstream users in Arizona, California and Nevada (the Lower Division states) can be met. The LROC define a normal year as a year in which annual pumping and release from Lake Mead will be sufficient to satisfy 7.5 maf of consumptive use in accordance with the Decree. A surplus year is defined as a year in which water in quantities greater than normal (i.e., greater than 7.5 maf) is available for pumping or release from Lake Mead pursuant to Article II(B)2 of the Decree after consideration of relevant factors, including the factors listed in the LROC. Surplus water is available to agencies which have contracted with the Secretary for delivery of surplus water, for use when their water demand exceeds their basic entitlement, and when the excess demand cannot be met within the basic apportionment of their state. Water apportioned to, but unused by one or more Lower Division states can be used to satisfy beneficial consumptive use requests of mainstream users in other Lower r Division states as provided in Article II(B)(6) of the Decree. Interio e 2017 of th pt.Secretary,29,an annual basis, to Pursuant to the CRBPA, the LROC are utilized De . by the ber on ion v Novem make determinations with respect to the projected plan of operations of the storage Nat va o h The on reservoirs in the Colorado RiverjBasin. ivedAOP is prepared by Reclamation, acting on in Na rc behalf of the Secretary, in consultation with representatives of the Colorado River Basin ited 6864, a c states (Basin States)14-1 and other parties, as required by federal law. The interim surplus No. to implement the provisions of Article III(3)(b) of the LROC on an criteria would serve annual basis in the determinations made by the Secretary as part of the AOP process. S.1.3.1 LONG-RANGE OPERATING CRITERIA The CRBPA required the Secretary to adopt operating criteria for the Colorado River by January 1, 1970. The LROC, adopted in 1970, control the operation of the Colorado River reservoirs in compliance with requirements set forth in the Compact, the CRSPA, the BCPA, the Treaty and other applicable federal laws. Under the LROC, the Secretary makes annual determinations in the AOP (discussed in the following section) regarding the availability of Colorado River water for deliveries to the Lower Division states (Arizona, California and Nevada). A requirement to equalize the active storage between Lake Powell and Lake Mead when there is sufficient storage in the Upper Basin is also included in Section 602(a) of the LROC, as required by the CRBPA. Section 602 of the CRBPA, as amended, provides that the LROC can only be modified after correspondence with the governors of the seven Basin States and appropriate consultation with such state representatives as each governor may designate. The LROC call for formal reviews at least every five years. The reviews are conducted as a COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 10 of 1200 EXECUTIVE SUMMARY public involvement process and are attended by representatives of federal agencies, the seven Basin States, Indian Tribes, the general public including representatives of the academic and scientific communities, environmental organizations, the recreation industry and contractors for the purchase of federal power produced at Glen Canyon Dam. Past reviews have not resulted in any changes to the criteria. S.1.3.2 ANNUAL OPERATING PLAN The CRBPA requires preparation of an AOP for the Colorado River reservoirs that guides the operation of the system for the water year. The AOP describes how Reclamation will manage the reservoirs over a 12-month period, consistent with the LROC and the Decree. The AOP is prepared annually by Reclamation in cooperation with the Basin States, other federal agencies, Indian Tribes, state and local agencies and the general public, including governmental interests as required by federal law. As part of the AOP process, the Secretary makes annual determinations regarding the availability of Colorado River water for deliveries to the Lower Division states as described below. The Secretary is required to determine when normal, surplus or shortage conditions occur in the lower Colorado River, based on various factors including storage and hydrologic conditions in the Colorado River Basin. ior Inter mainstream water Normal conditions exist when the Secretary determines thathe sufficient 017 of t p use e 29, 2 is available to satisfy 7.5 maf of annual consumptive t. in therLower Division states. . De b If a state will not use all of its apportionedn v for ovem the Secretary may allow io water N the year, at jo N ed on other states of the Lower Division to usevthe unused apportionment, provided that the Navawithrchiconsuming entity. use is covered under ain contract a the cited 16864, 14Surplus conditions exist when the Secretary determines that sufficient mainstream water No. is available for release to satisfy consumptive use in the Lower Division states in excess of 7.5 maf annually. This excess consumptive use is surplus and is distributed for use in California, Arizona and Nevada in allocations of 50, 46 and 4 percent, respectively. As stated above, if a state will not use all of its apportioned water for the year, the Secretary may allow other states of the Lower Division to use the unused apportionment, provided that the use is covered under a contract with the consuming entity. Surplus water under the Decree, for use in the Lower Division states, was made available by the Secretary in calendar years 1996, 1997, 1998, 1999 and 2000. Deliveries of surplus water to Mexico in accordance with the Treaty were made in calendar years 1983-1988, 1997, 1998, 1999 and 2000. Shortage conditions exist when the Secretary determines that insufficient mainstream water is available to satisfy 7.5 maf of annual consumptive use in the Lower Division states. When making a shortage determination, the Secretary must consult with various parties, as set forth in the Decree and consider all relevant factors as specified in the LROC (described above), including Treaty obligations, the priorities set forth in the Decree and the reasonable consumptive use requirements of mainstream water users in COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 11 of 1200 EXECUTIVE SUMMARY the Lower Division. The Secretary is required to first provide for the satisfaction of the presented perfected rights (PPRs) in the order of their priority, then to users who held contracts on September 30, 1968 (up to 4.4 maf in California) and finally to users who had contracted on September 30, 1968, when the CAP was authorized. To date, a shortage has never been determined. S.1.4 PURPOSE AND NEED FOR ACTION To date, the Secretary has applied factors, including but not limited to those found in Article III(3)(b)(i-iv) of the LROC, in annual determinations of the availability of surplus quantities of water for pumping or release from Lake Mead. As a result of actual operating experience and through preparation of AOPs, particularly during recent years when there has been increasing demand for surplus water, the Secretary has determined that there is a need for more specific surplus criteria, consistent with the Decree and applicable federal law, to assist in the Secretary’s annual decision making during an interim period. For many years, California has been diverting more than its normal 4.4 maf apportionment. Prior to 1996, California utilized unused apportionments of other Lower Division states that were made available by the Secretary. Since 1996, California has also utilized surplus water made available by Secretarial determination. ior Inter 17 of California is in the process of developing the means to reducee annual use f th its 20 pt. o full use 9, its apportionment Colorado River water to 4.4 maf. Arizona is approaching ber 2 of v. De v 2000. and Nevada was expected to reach itsation apportionment inem No jo N d on Navaofarchiveinterim surplus criteria, the Secretary will be n Additionally, through iadoption , specific cited 16864of Colorado River water, particularly those in able to afford mainstream users 14California who currently utilize surplus flows, a greater degree of predictability with No. respect to the likely existence, or lack thereof, of surplus conditions on the river in a given year. Adoption of the interim surplus criteria is intended to recognize California’s plan to reduce reliance on surplus deliveries, to assist California in moving toward its allocated share of Colorado River water and to avoid hindering such efforts. Implementation of interim surplus criteria would take into account progress, or lack thereof, in California’s efforts to achieve these objectives. The surplus criteria would be used to identify the specific amount of surplus water which may be made available in a given year, based upon factors such as the elevation of Lake Mead, during a period within which demand for surplus Colorado River water will be reduced. The increased level of predictability with respect to the prospective existence and quantity of surplus water would assist in planning and operations by all entities that receive surplus Colorado River water pursuant to contracts with the Secretary. S.1.5 RELATIONSHIP TO UNITED STATES–MEXICO WATER TREATY Under Article 10(a) of the Treaty, the United Mexican States (Mexico) is entitled to an annual amount of 1.5 maf of Colorado River water. Under Article 10(b) of the Treaty, Mexico may schedule up to an additional 0.2 maf when “there exists a surplus of waters COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 12 of 1200 EXECUTIVE SUMMARY of the Colorado River in excess of the amount necessary to satisfy uses in the United States.” This is in addition to surplus determinations for the Lower Division states made pursuant to Article II(2)(b) of the Decree and Article III(3)(B) of the LROC. The proposed action is not intended to identify, or change in any manner, conditions when Mexico may schedule this additional 0.2 maf. Under current practice, surplus declarations under the Treaty for Mexico are declared when flood control releases are made. Reclamation is currently engaged in discussions with Mexico through the IBWC on the effects of the proposed action. S.1.6 RELATED AND ON-GOING ACTIONS A number of ongoing and new actions proposed by Reclamation and other entities are related to the development of interim surplus criteria and the analysis contained in the FEIS. This section describes these actions and their relationship to the development of interim surplus criteria. The following actions have been described in environmental documents, consultation packages under Section 7 of the Endangered Species Act (ESA) or as project planning documents. Where appropriate, the FEIS incorporates by reference information contained in these documents. The documents described below are available for public inspection upon request at Reclamation offices in Boulder City, Nevada; Salt Lake City, Utah; and Phoenix and Yuma, Arizona. ior Inter 17 S.1.6.1 CALIFORNIA’S COLORADO RIVER WATER USEthLAN 0 f Pe pt. o er 29, 2 e .D mb California’s Colorado River Water Usetion v a Plan (CA Plan),ewhich was formerly known as Nov the California 4.4 Plan or thevajo N callsd on 4.4 Plan, e for conservation measures to be put in place i in Nadependencyvon surplus Colorado River water. Surplus that will reduce California’s 4, arch ited 686 c water is required to meet California’s current needs until implementation of the -1 o. 14 can take place. During the period ending in 2016, the State of conservation measures N California has indicated that it intends to reduce its reliance on Colorado River water to meet its water needs above and beyond its 4.4-maf apportionment. It is important for the long-term administration of the system to bring the Lower Basin uses into accordance with the Lower Basin normal apportionment. In order to achieve its goals, California has expressed a need to rely in some measure on the existence of surplus Colorado River water through 2016. These interim surplus criteria could aid California and its primary Colorado River water users as California reduces its consumptive use to 4.4 maf while ensuring that the other Basin States will not be placed at undue risk of future shortages. The CA Plan contains numerous water conservation projects, intrastate water exchanges and groundwater storage programs. The CA Plan is related to the implementation of the interim surplus criteria in the ways discussed below. First, implementation of the CA Plan is necessary to ensure the Colorado River system can meet the normal year deliveries in the Lower Basin over the long term. Failure of California to comply with the CA Plan places at risk the objective of providing reliable delivery of water for beneficial consumptive use to Lower Basin users. Therefore, the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 13 of 1200 EXECUTIVE SUMMARY Secretary may condition the continuation of interim surplus criteria for the entire period through 2016 on a showing of satisfactory progress in implementing the CA Plan. Regardless of which alternative is ultimately selected, failure of California to carry out the CA Plan may result in termination or suspended application of the proposed interim surplus criteria. In that event, the Secretary would fashion appropriate surplus criteria for the remaining period through 2016. Second, from the perspective of the State of California, because of the linkage between various elements of the CA Plan and the quantities of water involved, a reliable supply of interim surplus water from the Colorado River is an indispensable pre-condition to successful implementation of the CA Plan. From the standpoint of environmental documentation and compliance, the CA Plan and its various elements have been, or will be, addressed under separate federal and/or state environmental reporting procedures. S.1.6.1.1 Imperial Irrigation District/San Diego County Water Authority Water Transfer The Imperial Irrigation District (IID)/San Diego County Water Authority (SDCWA) water transfer is one of the intrastate exchanges that is a part of the erior CA Plan. SDCWA Int water 7 the IID. has negotiated an agreement for the long-term transfer of fconserved 01 from the pt. o water 2 Under the proposed contract, IID customers would undertakeer 29,conservation efforts . De emb to reduce their use of Colorado River ation v water. Water conserved through these efforts Nov would be transferred to SDCWA. The agreement sets the primary transfer quantity at a ajo N ived on Nav maximum of 200tkaf/year. After arleast 10 years of primary transfers, an additional d in 64, at ch ci e 168 discretionary component not to exceed 100 kaf/year may be transferred to SDCWA, the 14Metropolitan Water District of Southern California (MWD) or Coachella Valley Water No. District (CVWD) in connection with the settlement of water rights disputes between IID and these agencies. The initial transfer target date is 2002, or whenever the conditions necessary for the agreement to be finalized are satisfied or waived, whichever is later. This transfer is being addressed in an ongoing Environmental Impact Statement (EIS)/Environmental Impact Report (EIR) and involves the change in point of delivery of up to 300 kaf/year from Imperial Dam to Parker Dam. S.1.6.1.2 All-American and Coachella Canal Lining Projects Two other components of the CA Plan having effects on the river are the All-American and Coachella Canal Lining Projects (the Coachella Canal is a branch of the AllAmerican Canal). These two similar actions involve the concrete lining of unlined portions of the canals to conserve water presently being lost as seepage from the earthen reaches. Together the projects involve a change in point of delivery of 93.7 kaf/year from Imperial Dam for Parker Dam, 67.7 kaf/year for the All-American Canal and 26 kaf/year for the Coachella Canal. The effects of this change in point of delivery are being addressed in the Secretarial Implementation Agreement Environmental Assessment (EA) and Biological Assessment (BA). The Record of Decision (ROD) for COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 14 of 1200 EXECUTIVE SUMMARY the All-American Canal Lining Project was approved on July 29, 1994. Construction is expected to begin in 2001. A draft EIS/EIR for the Coachella Canal Lining Project was released on September 22, 2000 for public review. S.1.6.2 GLEN CANYON DAM OPERATIONS Glen Canyon Dam is operated consistent with the CRSPA and the LROC, which were promulgated in compliance with Section 602 of the CRBPA. Glen Canyon Dam is also operated consistent with the 1996 ROD on the Operation of Glen Canyon Dam FEIS developed as directed under the Grand Canyon Protection Act of 1992. The minimum release from Lake Powell, as specified in the LROC, is 8.23 maf per year. The LROC require that, when Upper Basin storage is greater than the storage required under Section 602(a) of the CRBPA, releases from Lake Powell will periodically be governed by the objective to maintain, as nearly as practicable, active storage in Lake Mead equal to the active storage in Lake Powell. Because of this equalization provision in the LROC, changes in operations at Lake Mead will, in some years, result in changes in annual release volumes from Lake Powell. It is through this mechanism that delivery of surplus water from Lake Mead can influence the operation of Glen Canyon Dam. Equalization is not required when there exists insufficient r storage in the Upper Basin, per Section 602(a) of the CRBPA. terio 7 he In . of t as29, 201 to In acknowledgement that the operation of Glen Dept Dam, r authorized, Canyon . mbe maximize power production was havingion v at a negative impact on downstream resources, Nove the Secretary determined inavajo N that an on should be prepared. The Operation July 1989 ed EIS in N 4, archivanalyzed alternative operation scenarios that of Glen Canyon Dam EIS developed and cited 1686 met statutory responsibilities for protecting downstream resources and achieving other 14authorized purposes, while protecting Native American interests. A final EIS was No. completed in March 1995 and the Secretary signed a ROD on October 8, 1996. Reclamation also consulted with the United States Fish and Wildlife Service (Service) under the ESA and incorporated the Service’s recommendations into the ROD. The ROD describes criteria and plans for dam operations and includes other measures to ensure Glen Canyon Dam is operated in a manner consistent with the Grand Canyon Protection Act of 1992. Among these are an Adaptive Management Program, periodic releases for beach/habitat-building flows (BHBFs), beach/habitat-maintenance flows and further study of temperature control. The ROD is based on the EIS, which contains descriptions and analyses of aquatic and riparian habitats below Glen Canyon Dam, effects of Glen Canyon Dam release patterns on the local ecology, cultural resources, sedimentation processes associated with the maintenance of backwaters and sediment deposits along the river, Native American interests, and relationships between release patterns and the value of hydroelectric energy produced. Analyses of effects on other resources within the affected area are also included. Additional information concerning the operation of Glen Canyon Dam is contained in Section 3.3. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 15 of 1200 EXECUTIVE SUMMARY S.1.6.2.1 Adaptive Management Program The Adaptive Management Program provides a process for assessing the effects of current operations of Glen Canyon Dam on downstream resources and using the results to develop recommendations for modifying operating criteria and other resource management actions. This is accomplished through the Adaptive Management Work Group (AMWG), a federal Advisory Committee. The AMWG consists of stakeholders that are federal and state resource management agencies, representatives of the seven Basin States, Indian Tribes, hydroelectric power marketers, environmental and conservation organizations and recreational and other interest groups. The duties of the AMWG are in an advisory capacity only. Coupled with this advisory role are long-term monitoring and research activities that provide a continual record of resource conditions and new information to evaluate the effectiveness of the operational modifications. S.1.6.2.2 Beach/Habitat-Building Flows and Beach/Habitat-Maintenance Flows BHBF releases are scheduled high releases of short duration that are in excess of power plant capacity required for dam safety purposes and are made according to certain specific criteria. These BHBFs are designed to rebuild high elevation sandbars, deposit nutrients, restore backwater channels and provide some of the dynamicsrof a natural terio system. The first test of a BHBF was conducted in spring of 1996. 2017 he In of t 9, pt. . De ateor near power plant capacity, ber 2 Beach/habitat-maintenance flow releaseson v are releases m Nati beachn Nov conditions for recreation which are intended to maintainajo v favorable ed o and habitat iv in NaprotectrTribal interests. Beach/habitat-maintenance flow and fish and wildlife, and to 4, a ch ited 686 releases can bec made 4-1 in years when no BHBF releases are made. o. 1 N Both beach/habitat-building and beach/habitat-maintenance flows, along with the testing and evaluation of other types of releases under the AMP, were recommended by the Service to verify a program of flows that would improve habitat conditions for endangered fish. The proposed interim surplus criteria could affect the range of storage conditions in Lake Powell and alter the flexibility to schedule and conduct such releases or to test other flow patterns. The magnitude of this reduction in flexibility has been evaluated in the FEIS for each interim surplus alternative. S.1.6.2.3 Temperature Control at Glen Canyon Dam In 1994, the Service issued a Biological Opinion on the Operation of Glen Canyon Dam (BO). One of the elements of the reasonable and prudent alternative in the BO, also a common element in the Glen Canyon Dam EIS, was the evaluation of methods to control release temperatures and, if viable, implement controls. Reclamation agreed with this recommendation and included it in the Operation of Glen Canyon Dam Final Environmental Impact Statement and subsequent ROD. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 16 of 1200 EXECUTIVE SUMMARY Reclamation has issued a draft planning report and EA entitled Glen Canyon Dam Modifications to Controls and Downstream Temperatures (Reclamation, 1999). Based on comments to this draft EA, Reclamation is currently in the process of preparing a new draft EA on temperature control at Glen Canyon Dam. Interim surplus criteria could result in new information related to temperature control at Glen Canyon Dam. Data and information made available from analysis related to interim surplus criteria will be utilized in the revised EA on temperature control at Glen Canyon Dam. Such information would also be considered in the development of an appropriate design for a temperature control device. S.1.6.3 ACTIONS RELATED TO THE BIOLOGICAL AND CONFERENCE OPINION ON LOWER COLORADO RIVER OPERATIONS AND MAINTENANCE Reclamation prepared a BA in accordance with Section 7 of the ESA, addressing effects of ongoing and projected routine lower Colorado River operations and maintenance (Reclamation, 1996). After formal consultation, a Biological and Conference Opinion (BCO) was prepared by the Service (Service, 1997). Pursuant to the reasonable and prudent alternative and 17 specific provisions provided in the BCO, Reclamation is taking various actions that benefit the riparian region of the lower Colorado River and associated species. In particular, these actions include: 1) acquisition,ior ter restoration and protection of potential and occupied Southwestern willow flycatcher habitat; he In 2017 of t ept. ber 29, 2) extensive life history studies for Southwestern willow flycatcher along 400 miles of v. D m the lower Colorado River and other areas; n 3) protection and enhancement of atio andon Nove N o endangered fish species throughjrisk assessments, assisted rearing and development of ed N va inthea 4, archiv River. This five-year BCO provides ESA protected habitats ed along lower Colorado cit 686 compliance for Reclamation actions on the lower Colorado River until 2002. 14-1 No. The BA and BCO contain life histories/status of lower Colorado River species, descriptions of ongoing and projected routine operation and maintenance activities, the Secretary’s discretionary management activities, operation and maintenance procedures, endangered species conservation program, environmental baseline, effects of ongoing operations, reasonable and prudent alternatives and supporting documentation useful in this FEIS. The 1996 BA and the 1997 BCO did not anticipate or address the effects of specific interim surplus criteria on the species considered. A separate Section 7 ESA consultation is in progress for the proposed action. S.1.6.4 LOWER COLORADO RIVER MULTI-SPECIES CONSERVATION PROGRAM Following the designation of critical habitat for three endangered fish species on nearly all of the lower Colorado River in April of 1994, the three Lower Basin states of Arizona, California and Nevada, Reclamation and the Service initiated the Lower Colorado River Multi-Species Conservation Program (LCRMSCP), which was one of the reasonable and prudent provisions of the five-year BCO received in 1997. The purpose of the LCRMSCP is to obtain long-term (50-year) ESA compliance for both federal and non-federal water and power interests. The LCRMSCP is a partnership of COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 17 of 1200 EXECUTIVE SUMMARY federal, state, Tribal, and other public and private stakeholders with an interest in managing the water and related resources of the lower Colorado River Basin. In August 1995, Interior and Arizona, California and Nevada entered into a Memorandum of Agreement (MOA) and later a Memorandum of Clarification (MOC) for development of the LCRMSCP. The purpose of the MOA/MOC was to initiate development of an LCRMSCP that would accomplish the following objectives: • Conserve habitat and work toward the recovery of threatened and endangered species and reduce the likelihood of additional species listing under the ESA; and • Accommodate current water diversions and power production and optimize opportunities for future water and power development. The LCRMSCP is currently under development and it is anticipated that the final EISenvironmental impact report will be finalized in 2001. Once the LCRMSCP is accepted by the Service, Reclamation and other federal agencies, as well as the participating nonfederal partners, will have achieved ESA compliance for ongoing and future actions. Since the interim surplus criteria determination is scheduled to be completed prior to the completion of the LCRMSCP, a separate Section 7 consultation is in progress with the ior Service on the anticipated effects of implementing the interim surplus criteria. Inter 7 e 01 f th pt. o er 29, 2 e S.1.6.5 SECRETARIAL IMPLEMENTATION AGREEMENTb ELATED TO R v. D i IVER W Novem atRon onATER USE PLAN CALIFORNIA’S COLORADO jo N Nava archived in Within California,ed allocation, of Colorado River water is stipulated by various cit the 16864 existing agreements14among the seven parties with diversion rights. Recently, these No. parties have negotiated a Quantification Settlement Agreement that further defines the priorities for use of Colorado River water in California. This agreement provides a basis for various water conservation and transfer measures described in the CA Plan. The water transfers would require changes in the points at which the Secretary would deliver transferred water to various California entities, as compared with provisions in existing water delivery contracts. The operational changes caused by the water transfers are being addressed in separate NEPA and ESA documentation. S.1.6.6 OFFSTREAM STORAGE OF COLORADO RIVER WATER AND DEVELOPMENT AND RELEASE OF INTENTIONALLY CREATED UNUSED APPORTIONMENT IN THE LOWER DIVISION STATES The above titled rule establishes a procedural framework for the Secretary to follow in considering, participating in, and administering Storage and Interstate Release Agreements among the states of Arizona, California and Nevada (Lower Division states). The Storage and Interstate Release Agreements would permit state-authorized entities to store Colorado River water offstream, develop intentionally created unused apportionment (ICUA) and make ICUA available to the Secretary for release for use in COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 18 of 1200 EXECUTIVE SUMMARY another Lower Division state. This rule provides a framework only and does not authorize any specific activities. The rule does not affect any Colorado River water entitlement holder’s right to use its full water entitlement, and does not deal with intrastate storage and distribution of water. The rule only facilitates voluntary interstate water transactions that can help satisfy regional water demands by increasing the efficiency, flexibility and certainty in Colorado River management. A Finding of No Significant Impact was approved on October 1, 1999. S.2 ALTERNATIVES S.2.1 DEVELOPMENT OF ALTERNATIVES The FEIS considers five interim surplus criteria alternatives as well as a No Action Alternative/baseline that was developed for comparison of potential effects. The five action alternatives considered include the Basin States Alternative (preferred alternative), the Flood Control Alternative, the Six States Alternative, the California Alternative and the Shortage Protection Alternative. The following section discusses the strategies and origins of the action alternatives. Other alternatives, including a proposal by the Pacific Institute, were considered but eliminated from further analysis. Those alternatives, and the reasons for their elimination from further analysis, are discussed in ior Chapter 2 of Volume I. Inter e of th 29, 2017 pt. BASIN STATES ALTERNATIVES S.2.1.1 ORIGINS OF CALIFORNIA, SIX STATESe . D AND ber ion v Novem Nat Basin States its draft 4.4 Plan, a plan to In 1997, California presentedvajthe other ed on to o n Na rc iv achieve a reduction d iits dependence h surplus water from the Colorado River, ite in 6864, a on c through various conservation measures, water exchanges and conjunctive use programs. -1 o. 14 the draft 4.4 Plan was the expectation that the Secretary would N One of the elements of continue to determine surplus conditions on the Colorado River until 2015. California proposed criteria on which the Secretary would base his determinations of surplus conditions during the interim period. In 1998, in response to California’s proposal of interim surplus criteria, the other six states within the Colorado River Basin (Six States) submitted a proposal with surplus criteria that were similar in structure to those in California’s proposal. Under the proposal from the Six States, use of surplus water supplies would be limited depending on the occurrence of various specified Lake Mead surface elevations. The interim surplus criteria proposed by the Six States were used to formulate the “Six States Alternative.” California subsequently proposed specific interim surplus criteria that were attached to the October 15, 1999 Key Terms for Quantification Settlement Among the State of California, Imperial Irrigation District, Coachella Valley Water District, and Metropolitan Water District of Southern California. California also updated, renamed and re-released its 4.4 Plan in May 2000. The revised plan is now known as California’s Colorado River Water Use Plan (CA Plan). The interim surplus criteria COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 14 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 19 of 1200 EXECUTIVE SUMMARY proposal stemming from the CA Plan and Quantification Settlement Agreement was used to formulate the "California Alternative." In July 2000, during the public comment period on the DEIS, Reclamation received a draft proposal for interim surplus criteria from the seven Colorado River Basin States (Seven States). After a preliminary review of that proposal, Reclamation published it in the August 8, 2000 Federal Register for review and consideration by the public during the public review period for the DEIS. Reclamation published minor corrections to the proposal in a Federal Register notice of September 22, 2000. Reclamation derived the Basin States Alternative in the FEIS from the draft Seven States Proposal. S.2.1.2 UTILIZATION OF PROPOSALS FROM BASIN STATES Various proposals submitted by individual Colorado River Basin states or groups of states were used by Reclamation to formulate interim surplus criteria alternatives. In recognition of the need to limit the delivery of surplus water at lower Lake Mead water levels, these proposals specified allowable uses of surplus water at various triggering levels. The Secretary will continue to apportion surplus water consistent with the applicable provisions of the Decree, under which surplus water is divided 50 percent to California, rior Inteintends to e 46 percent to Arizona, and 4 percent to Nevada. The Secretary also 017 2 of th to MWD under surplus appropriately report the accumulated volume of Dept.delivered 29, water . any forbearance arrangements made by ber em conditions. The Secretary also intends tiohonor to n v Na watern Nov various parties for the deliveryajosurplus ed o or reparations for future shortage v of in Na 4, archiv conditions. ted ci 1686 . 14- OF ALTERNATIVES S.2.2 DESCRIPTION No S.2.2.1 NO ACTION ALTERNATIVE AND BASELINE CONDITIONS As required by NEPA, a No Action alternative must be considered during the environmental review process. Under the No Action Alternative, determinations of surplus would continue to be made on an annual basis, in the AOP, pursuant to the LROC and the Decree as discussed above. The No Action Alternative represents the future AOP process without interim surplus criteria. Surplus determinations consider such factors as end-of-year system storage, potential runoff conditions, projected water demands of the Basin States and the Secretary’s discretion in addressing year-to-year issues. However, the year-to-year variation in the conditions considered by the Secretary in making surplus water determinations makes projections of surplus water availability highly uncertain. The approach used in the FEIS for analyzing the hydrologic aspects of the interim surplus criteria alternatives was to use a computer model that simulates specific operating parameters and constraints. In order to follow CEQ guidelines calling for a No Action alternative for use as a “baseline” against which to compare project COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 15 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 20 of 1200 EXECUTIVE SUMMARY alternatives, Reclamation selected a specific operating strategy for use as a baseline condition, which could be described mathematically in the model. The baseline is based on a 70R spill avoidance strategy (as described in Section S.2.2.1.2). Reclamation has utilized a 70R strategy for both planning purposes and studies of surplus determinations in past years. While the 70R strategy is used to represent baseline conditions, it does not represent a decision by Reclamation to utilize the 70R strategy for determination of future surplus conditions in the absence of interim surplus criteria. S.2.2.1.1 Approach to Surplus Water Determination As discussed above, the 70R operating strategy is being used as a baseline to show possible future operating conditions in the absence of interim surplus criteria. The primary effect of simulating operation with the 70R operating strategy would be that surplus conditions would only be determined when Lake Mead is nearly full. S.2.2.1.2 70R Baseline Surplus Triggers The 70R baseline strategy involves assuming a 70-percentile inflow into the system, subtracting out the consumptive uses and system losses and checkingrior results to see e the if all of the water could be stored or if flood control releaseshe Int be required. If flood would 017 ft control releases would be required, additional waterpt.made available to the Lower is o 29, 2 er . De Basin states beyond 7.5 maf. The notation 70R refersvembspecific inflow where 70 ion v No to the Nat percent of the historical natural runoff is less than this value (17.4 maf) for the Colorado vajo hived on a River basin at Leeed in N Ferry. , arc cit 864 4-16 approximately 1199 feet msl in 2002 to 1205 feet msl in The 70R trigger o. 1rises from N line 2050. The gradual rise of the 70R trigger line is the result of increasing water use in the Upper Basin. Under baseline conditions, when a surplus condition is determined to occur, surplus water would be made available to fill all water orders by holders of surplus water contracts in the Lower Division states. S.2.2.2 BASIN STATES ALTERNATIVE (PREFERRED ALTERNATIVE) Reclamation has identified the Basin States Alternative as the preferred alternative in the FEIS. The Basin States Alternative is similar to, and based upon, information submitted to the Secretary by representatives of the governors of the states of Colorado, Wyoming, Utah, New Mexico, Arizona, Nevada and California. After receipt of this information (during the public comment period), Reclamation shared the submission with the public (through the Federal Register and Reclamation’s surplus criteria web sites) for consideration and comment. Reclamation then analyzed the states’ submission and crafted this additional alternative for inclusion in the FEIS. Some of the information submitted for the Department’s review was outside of the scope of the proposed action for adoption of interim surplus criteria and was therefore not included as part of the Basin States Alternative (e.g., adoption of shortage criteria and adoption COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 16 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 21 of 1200 EXECUTIVE SUMMARY of surplus criteria beyond the 15-year period) as presented in this FEIS. With respect to the information within the scope of the proposed action, Reclamation found the Basin States Alternative to be a reasonable alternative and has fully analyzed all environmental effects of this alternative in this FEIS. The identified environmental effects of the Basin States Alternative are well within the range of anticipated effects of the alternatives presented in the DEIS and do not affect the environment in a manner not already considered in the DEIS. Reclamation selected the Basin States Alternative as its preferred alternative based on Reclamation’s determination that it best meets all aspects of the purpose and need for the action, including the needs to remain in place for the entire period of the interim criteria, to garner support among the Basin States that will enhance the Secretary’s ability to manage the Colorado River reservoirs in a manner that balances all existing needs for these precious water supplies, and to assist in the Secretary’s efforts to insure that California water users reduce their over reliance on surplus Colorado River water. Reclamation notes the important role of the Basin States in the statutory framework for administration of Colorado River Basin entitlements and the significance that a sevenstate consensus represents on this issue. Thus, based on all available information, this alternative appears to be the most reasonable and feasible alternative analyzed. ior Inter 17 0 f the pt. o water9, 2 elevations to The Basin States Alternative specifies ranges ofDe Mead er 2 surface Lake v. mb be used through 2015 for determiningatioavailability vesurplus water through 2016. the n No of o j N specific n The elevation ranges are coupledo Nava withhived uses of surplus water in such a way that, in rc to decline, the amount of surplus water would be a if Lake Mead’s surface elevation were cited 16864, reduced. The interim41 criteria would be reviewed at five-year intervals with the LROC No. (and additionally as needed), and revised as needed based upon actual operational S.2.2.2.1 Approach to Surplus Water Determination experience. S.2.2.2.2 Basin States Alternative Surplus Triggers The surplus determination elevations under the Basin States Alternative consist of the tiered Lake Mead water surface elevations listed below, each of which is associated with certain stipulations on the purposes for which surplus water could be used. Proceeding from higher to lower water levels, the elevation tiers (also referred to as levels) are as follows: Tier 1 - 70R Line (approximately 1199 to 1201 feet msl) Tier 2 - 1145 feet msl Tier 3 - 1125 feet msl COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 17 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 22 of 1200 EXECUTIVE SUMMARY S.2.2.3 FLOOD CONTROL ALTERNATIVE S.2.2.3.1 Approach to Surplus Water Determination Under the Flood Control Alternative, a surplus condition is determined to exist when flood control releases from Lake Mead are occurring or projected to occur in the subsequent year. The method of determining need for flood control releases is based on flood control regulations published by the Los Angeles District of the United States Army Corps of Engineers (Corps) and the Field Working Agreement between the Corps and Reclamation. S.2.2.3.2 Flood Control Alternative Surplus Triggers Under the flood control strategy, a surplus is determined when the Corps flood control regulations require releases from Lake Mead in excess of downstream demand. If flood control releases are required, surplus conditions are determined to be in effect. The average flood control triggering elevation is approximately 1211 feet msl. In practice, flood control releases are not based on the average trigger elevation, but would be determined each month by following the Corps regulations. When a flood control surplus is determined, surplus water would be made available for all established uses by contractors for surplus water in the Lower Division states. erior Int f the 9, 2017 S.2.2.4 SIX STATES ALTERNATIVE pt. o . De ember 2 v tion n Nov N Water Determination S.2.2.4.1 Approach to Surplusa vajo ed o in Na 4, archiv d The Six States cite Alternative specifies ranges of Lake Mead water surface elevations to be 1686 used through 2015 for determining the availability of surplus water through 2016. The . 14No elevation ranges are coupled with specific uses of surplus water in such a way that, if Lake Mead’s surface elevation were to decline, the amount of surplus water would be reduced. The interim criteria would be reviewed at five-year intervals with the LROC and as needed based upon actual operational experience. S.2.2.4.2 Six States Alternative Surplus Triggers The surplus determination elevations under the Six States Alternative consist of the tiered Lake Mead water surface elevations listed below, each of which is associated with certain stipulations on the purposes for which surplus water could be used. The tiered elevations are as follows, proceeding from higher to lower water levels: Tier 1 - 70R Line (approximately 1199 to 1201 feet msl) Tier 2 - 1145 feet msl Tier 3 - 1125 feet msl COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 18 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 23 of 1200 EXECUTIVE SUMMARY S.2.2.5 CALIFORNIA ALTERNATIVE S.2.2.5.1 Approach to Surplus Water Determination The California Alternative specifies Lake Mead water surface elevations to be used for the interim period through 2015 for determining the availability of surplus water through 2016. The elevation ranges are coupled with specific uses of surplus water in such a way that, if Lake Mead’s surface elevation declines, the amount of surplus water would be reduced. S.2.2.5.2 California Alternative Surplus Triggers The Lake Mead elevations at which surplus conditions would be determined under the California Alternative are indicated by a series of tiered, sloping lines from the present to 2016. Each tiered line would be coupled with limitations on the amount of surplus water available at that tier. Each tier is defined as a trigger line that rises gradually year by year to 2016, in recognition of the gradually increasing water demand of the Upper Division states. The elevations associated with the three tiers are as follows: Tier 1 - 1160 feet msl to 1166 feet msl Tier 2 - 1116 feet msl to 1125 feet msl Tier 3 - 1098 feet msl to 1102 feet msl ior Inter 17 0 f the pt. o er 29, 2 e v. D S.2.2.6 SHORTAGE PROTECTION ALTERNATIVE vemb ation on No ajo N d S.2.2.6.1 ApproachNav archive Determination to Surplus Water d in 64, cite 168 14The Shortage Protection Alternative is based on maintaining an amount of water in No. to provide a normal annual supply of 7.5 maf for the Lower Lake Mead necessary Division, 1.5 maf for Mexico and storage necessary to provide an 80 percent probability of avoiding future shortages. S.2.2.6.2 Shortage Protection Alternative Surplus Triggers The surplus triggers under this alternative range from an approximate Lake Mead initial elevation of 1126 feet msl to an elevation of 1155 feet msl at the end of the interim period. At Lake Mead elevations above the surplus trigger, surplus conditions would be determined to be in effect and surplus water would be available for use by the Lower Division states. Below the trigger-elevation, surplus water would not be made available. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 19 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 24 of 1200 EXECUTIVE SUMMARY S.3 S.3.1 SUMMARY OF ENVIRONMENTAL CONSEQUENCES USE OF MODELING TO IDENTIFY POTENTIAL FUTURE COLORADO RIVER SYSTEM CONDITIONS To determine the potential effects of the interim surplus criteria alternatives, modeling of the Colorado River system was conducted. Modeling provides projections of potential future Colorado River system conditions (i.e., reservoir surface elevations, river flows, salinity, etc.). The modeling results allow a comparison of potential future conditions under the various interim surplus criteria alternatives and baseline conditions. As such, much of the analyses contained within the FEIS are based upon potential effects of changed flows and water levels within the Colorado River and mainstream reservoirs. S.3.2 BASELINE CONDITIONS As discussed above, the No Action Alternative does not provide consistent specific criteria for determining surplus conditions. As such, it is not possible to model the No Action Alternative. However, in order to provide a reasonable analytical projection of potential future system conditions without interim surplus criteria, a reasonable baseline surplus strategy (70R) was utilized. This baseline represents a definablersurplus criteria terio he In 2017 secretarial based on recent operational decisions. The 70R strategy is tbased upon recent . of of 29, operating decisions and was modeled to develop aept projectioner baseline conditions for v. D vemb comparison with the alternatives in NatFEIS. the ion No on jo Nava archived S.3.3 IMPACTted in DETERMINATION APPROACH 4, ci 1686 14The analysis of potential effects for each issue considered is based primarily upon the No. results of modeling. Following the identification of conditions important to each issue, the potential effects of various system conditions over the general range of their possible occurrence (as identified by the range of modeling output for various parameters) are identified for each issue. The potential effects of the various interim surplus criteria alternatives are presented in terms of the incremental differences in probabilities (or projected circumstances associated with a given probability) between baseline conditions and the alternatives. S.3.4 PERIOD OF ANALYSIS The FEIS addresses interim surplus criteria that would be used during the years 2001 through 2015 for determining whether surplus water would be available during the years 2002 through 2016. Due to the potential for effects beyond the 15-year interim period, the modeling and impact analyses extend through the year 2050. It is important to note that modeling output and associated impact analyses become more uncertain over time as a result of increased uncertainty of future system conditions (including hydrologic conditions), as well as uncertainty with regard to future operational decisions that will affect circumstances within the Colorado River system. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 20 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 25 of 1200 EXECUTIVE SUMMARY S.3.5 POTENTIALLY AFFECTED AREA Interim surplus criteria could affect the operation of the Colorado River system (i.e., reservoir levels and river flow volumes) as a result of surplus determinations and associated water deliveries that may not have occurred in the absence of such criteria. Interim surplus criteria are based on system conditions and hydrology. Water supply to the Lower Division states of Arizona, California and Nevada is achieved primarily through releases and pumping from Lake Mead. As a result of Lake Powell and Lake Mead equalization requirements, interim surplus criteria effects on Lake Mead surface elevations could also influence Lake Powell surface elevations and Glen Canyon Dam releases. However, operation of the other Upper Basin reservoirs is independent of Lake Powell. Therefore, the upstream limit of the potentially affected area under consideration in this FEIS is the full pool elevation of Lake Powell. The downstream limit within the United States is the Southerly International Boundary (SIB) between the United States and Mexico (see Map S-1). Also addressed in the FEIS are potential transboundary impacts in Mexico pursuant to Executive Order 12114 - Environmental Effects Abroad of Major Federal Actions, January 4, 1997, and the July 1, 1997 Council on Environmental Quality (CEQ) Guidelines on NEPA Analyses for Transboundary Impacts. ior Inter it is recognized In addition to influencing conditions within the Colorado fRiver system, 17 the 0 pt. ofrom r 29, 2surplus criteria that continued delivery of surplus water that coulde result beinterim v. D would recognize ongoing and proposedtistate actionsovemLower Basin. These actions a on on N in the N could result in environmentalvajo outside of the river corridor. However, these Na effectschived in actions have independent utility , ar are not caused by or dependent on interim surplus cited 16864 and criteria for their implementation. Environmental compliance would be required on a 14No. case-by-case basis prior to their implementation. Therefore, Reclamation determined that the appropriate scope of this analysis is to consider only those potential effects that could occur within the Colorado River corridor as defined by the 100-year flood plain and reservoir maximum water surface elevations. S.3.6 COMPARISON OF SURPLUS ALTERNATIVES TO BASELINE CONDITIONS S.3.6.1 EFFECTS ON RESERVOIR SURFACE ELEVATIONS AND RIVER FLOWS Figures S-1 and S- 2 present the 90th, 50th and 10th percentile Lake Powell and Lake Mead surface elevations indicated through system modeling for baseline conditions and the interim surplus criteria alternatives. These figures can be used for comparing the relative differences in the general lake level trends that result from the simulation of future conditions under the baseline and the interim surplus criteria alternatives. A complete explanation of the modeling process and results can be found in Section 3.3 of the FEIS. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 21 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 26 of 1200 EXECUTIVE SUMMARY Figure S-1 Lake Powell End-of-July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions th th th 90 , 50 and 10 Percentile Values 3720 90th Percentile 3700 3680 Water Surface Elevation (feet) 3660 50th Percentile 3640 3620 3600 10th Percentile 3580 Baseline Conditions 3560 Basin States Alternative Flood Control Alternative 3540 Six States Alternative 3520 California Alternative Shortage Protection Alternative 3500 2000 r 2040 io Inter 12045 0 7 f the pt. o er 29, 2 Figure S-2 e b v. D v Elevations Lake Mead End-of-December Water em ation on and Baseline Conditions No Comparison of ajo N Alternatives Surplus v th th and 10thd e in Na904,,50 rchiv Percentile Values a d cite 1686 14No. 2005 2010 2015 2020 2025 2030 2035 2050 Year 1220 1200 90th Percentile 1180 1160 Wa ter Su 1140 rfa ce Ele 1120 vat ion (fe et) 1100 50th Percentile 1080 1060 1040 Baseline Conditions Basin States Alternative Flood Control Alternative 1020 Six States Alternative California Alternative 10th Percentile Shortage Protection Alternative 1000 2000 2005 2010 2015 2020 2025 Year COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 22 2030 2035 2040 2045 2050 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 27 of 1200 EXECUTIVE SUMMARY As illustrated in Figure S-1, the Flood Control Alternative could potentially result in the highest Lake Powell water levels. The Shortage Protection Alternative and the California Alternative could potentially result in the lowest water levels. The baseline conditions yield similar levels to those observed under the Flood Control Alternative. The water levels observed under the California Alternative are similar to those observed under the Shortage Protection Alternative. The results obtained under the Six States and Basin States alternatives are similar, and fall between baseline conditions and the Shortage Protection Alternative. As illustrated in Figure S-2, the Flood Control Alternative could potentially result in the highest Lake Mead water levels. The California Alternative could potentially result in the lowest water levels. The water levels observed under the Shortage Protection Alternative are similar to those of the California Alternative, with some years slightly lower. The baseline conditions yield slightly lower levels than the Flood Control Alternative, but the differences are very small. The results obtained under the Six States and Basin States alternatives are similar, and fall between the Flood Control and Shortage Protection alternatives. River flows would be affected to a limited degree by the interim surplus criteria ior alternatives. Flows from Glen Canyon Dam, which would be influenced by the Inter 17 adoption of interim surplus criteria, will remain within the range of , 20 analyzed in f the 9flows pt. o potential changes in the detail in the Glen Canyon Dam EIS. Therefore,De effects of ber 2 m n v. frequencies of these flows on downstream resourcesove no further analysis outside of Natio d on N need o the ROD for Glen Canyon Dam joperations and the Adaptive Management Program. Nava hive in arc cited 16864, River flows in the reaches between Hoover Dam and the SIB would also be affected to . 14N by a limited degree o the interim surplus criteria alternatives. Flows to meet downstream demands would typically increase, but remain well within the current operational ranges for those reaches. The frequency of large flows in those reaches due to flood control releases at Hoover Dam would typically decrease. Detailed discussions of the potential effects on river flows are included in Sections 3.3 and 3.6 of the FEIS. S.3.6.2 SUMMARY OF ENVIRONMENTAL IMPACTS Table S-1 summarizes the potential effects of interim surplus criteria on the various resource issues analyzed in the FEIS. S.3.6.3 ENVIRONMENTAL COMMITMENTS Impacts are associated with changes in the difference between probabilities of occurrence for specific resource issues under study when comparing the action alternatives to baseline conditions. Reclamation has determined that most of the potential impacts identified are not of a magnitude that would require specific mitigation measures to reduce or eliminate their occurrence because the small changes in probabilities of occurrence are within Reclamation’s current operational regime and COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 23 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 28 of 1200 EXECUTIVE SUMMARY authorities under applicable federal law. In recognition of potential effects that could occur under baseline conditions or with implementation of the interim surplus criteria alternatives under consideration, Reclamation has developed a number of environmental commitments, described below, that will be undertaken if interim surplus criteria are implemented. Some commitments are the result of compliance with specific consultation requirements. S.3.6.3.1 Water Quality Reclamation will continue to monitor salinity and total dissolved solids on the Colorado River as part of the ongoing Colorado River Basin Salinity Control Program to ensure compliance with the numeric criteria on the river as set forth in the Forum’s 1999 Annual Review. Reclamation will continue to participate in the Lake Mead Water Quality Forum and the Las Vegas Wash Coordination Committee as a principal and funding partner in studies of water quality in the Las Vegas Wash and Lake Mead. Reclamation is an active partner in the restoration of the Las Vegas Wash wetlands. Reclamation is acquiring and will continue to acquire riparian and wetland habitat around Lake Mead and on the Lower Colorado River related to ongoing rand projected terio routine operations. he In 017 ft o 9, 2 ept. . DNevadamber 2 of Environmental Reclamation will continue to participateion vthe ove Division t with n N NaCompany in the perchlorate remediation program o Protection and Kerr-McGee Chemical ed o avaj rc iv of groundwater dischargeN in points,alonghLas Vegas Wash that will reduce the amount of 4 a c ted 1 the Colorado River. this contaminantientering 686 14No. Reclamation will continue to monitor river operations, reservoir levels and water supply and make this information available to the Colorado River Management Work Group, agencies and the public. See also Reclamation’s website (http://www.lc.usbr.gov and http://www.uc.usbr.gov). S.3.6.3.2 Riverflow Issues Reclamation will continue to work with the stakeholders in the Adaptive Management Program to develop an experimental flow program for the operations of Glen Canyon Dam which includes BHBFs and is designed to protect, mitigate adverse impacts to and improve the values for which GCNP and GCNRA were established. S.3.6.3.3 Aquatic Resources Reclamation will initiate a temperature monitoring program below Hoover Dam with state and other federal agencies to document temperature changes related to baseline and implementation of interim surplus criteria and assess their potential effects on listed COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 24 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 29 of 1200 EXECUTIVE SUMMARY species and the sport fishery. The existing hydrolab below Hoover Dam will be modified as necessary to provide this temperature data. S.3.6.3.4 Special-Status Species Section 7 consultation is in progress and commitments will be identified in the Record of Decision. S.3.6.3.5 Recreation Reclamation is initiating a bathymetric survey of Lake Mead in fiscal year 2001 and will coordinate with the Lake Mead National Recreation Area to identify critical recreation facility elevations and navigational hazards that would be present under various reservoir surface elevations. Reclamation will continue to monitor river operations, reservoir levels and water supply and make this information available to the Colorado River Management Work Group, agencies and the public. This operational information will provide the Lake Mead National Recreation Area and the Glen Canyon National Recreation Area with probabilities for future reservoir elevations to assist in management of navigational aids, recreation facilities, other resources and fiscal planning. rior Inte 1 f the the Glen 7 o Reclamation will continue its consultation and coordination with29, 20 Canyon ept. . Don theember National Recreation Area and the Navajo Nation development of Antelope Point nv Natio d on Nov as a resort destination. vajo e in Na 4, archiv d Resources cite S.3.6.3.6 Cultural1686 14No.continue to consult and coordinate with the State Historic Reclamation shall Preservation Officer, the Advisory Council on Historic Preservation (Council), Glen Canyon National Recreation Area, Lake Mead National Recreation Area, Tribes and interested parties with regard to the potential effects of the proposed action as required by Sections 106 and 110 of the National Historic Preservation Act following the Council’s recommended approach for consultation for the Protection of Historic Properties found at 36 CFR 800. S.3.6.3.7 Transboundary Impacts It is the position of the United States State Department, through the United States Section of the International Boundary and Water Commission (USIBWC), that the United States does not mitigate for impacts in a foreign county. The United States will continue to participate with Mexico through the USIBWC Technical Work Groups to develop cooperative projects beneficial to both countries. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 25 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 30 of 1200 EXECUTIVE SUMMARY S.4 OTHER NEPA CONSIDERATIONS S.4.1 CUMULATIVE IMPACTS A cumulative impact is an impact that results from the incremental impact of the action when added to other past, present and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time (40 CFR 1508.7). Effects that could occur within the United States as a result of interim surplus criteria are each associated with potential changes in the probabilities for Lake Mead and Lake Powell surface elevation reductions and changes in Colorado River flows from Glen Canyon Dam to the SIB. Generally, other actions that could result in cumulative impacts when considered in tandem with the effects of interim surplus criteria have been incorporated into modeling of future system conditions. Such actions include future increases in consumptive use of Colorado River water in the Upper Division states, intrastate water transfers in the Lower Division states and various requirements and constraints applied to the operation of the Colorado River system. or The environmental effects of the various components of the CA Plan, iincluding the Inter 17 various intrastate storage facilities (such as Cadiz, Hayfield/Chuckwalla and 0 f the pt. o er 29, 2 undergoing Desert/Coachella projects) and the other relatedDe ongoing actions, are and b v. separate compliance. Where there is ation nexus toem a federal Nov actions in California, a on jo N combined California Environmental Quality Act (CEQA) and NEPA compliance Nava archived document is beinged in cit prepared. 64, 8 4-16 . 1effects to the resources affected by surplus criteria were analyzed No Potential cumulative within the 100-year floodplain of the lower Colorado River from the full-pool elevation of Lake Powell to the Gulf of California in Mexico through year 2050. Only the issue area of “transboundary impacts” was identified as possibly experiencing cumulative effects. No past, present or reasonably foreseeable actions in the United States are expected to result in cumulative impacts to the issue area of transboundary impacts. In addition to the direct and indirect effects on the physical and natural environment in Mexico from actions identified by Mexico, it is recognized that some future actions taken by Mexico may have a cumulative effect. Exactly what these action are is not known at this time. Any impacts of these projects are the responsibility of Mexico. In addition, Reclamation is consulting with the Service on potential adverse effects to species found in both Mexico and the United States. For potentially affected species found only in Mexico, Reclamation is consulting with the National Marine Fisheries Service. Concurrent with these consultations, Reclamation is also continuing dialog with Mexico, through the IBWC’s Fourth Technical Work Group, to reach mutually agreeable solutions to address cumulative impacts. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 26 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 31 of 1200 EXECUTIVE SUMMARY S.4.2 RELATIONSHIP BETWEEN SHORT-TERM USES OF THE ENVIRONMENT AND LONG-TERM PRODUCTIVITY Because the implementation of interim surplus criteria is a management action that would require no direct physical change to the environment, for the purposes of this discussion, short-term uses of resources are limited to potential changes in the probability for certain environmental effects to occur as a result of changed system conditions. Also for the purposes of this discussion, long-term productivity refers to the benefits that would be realized during and following the period in which interim surplus criteria would be in place. The benefit sought by means of the interim surplus criteria alternatives consists of increasing the efficiency of the Secretary's annual decision-making process regarding the availability of Colorado River water. This would afford the mainstream users of this water a greater degree of predictability which would assist them in their water resources planning and operation. The resources that may be affected in the short-term would be primarily those affected by lower reservoir levels. The effects of the interim surplus criteria on those resources would depend on the alternative selected for implementation. The Flood Control Alternative would result in insignificant changes in reservoir levelserior baseline nt from conditions. The other four alternatives would tend to causethe I average 7 lower 201 water levels of , than baseline conditions by 2016 and for a limitedept. ofber 29 period time thereafter. However, .D nv em these alternatives would have a greater tprobabilityNosurplus water than the Flood Na io d on of v o Control Alternative or baseline conditionse avaj r hiv through the year 2016. Long-term benefits in Nto interimcsurplus criteria would include increased that would be realized due 64, a cited 168 opportunities for making more efficient use of Colorado River water supplies. 14- No. S.4.3 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES Irreversible commitments are decisions affecting renewable resources such as soils, wetlands and waterfowl habitat. Such decisions are considered irreversible because their implementation would affect a resource that has deteriorated to the point that renewal can occur only over a long period of time or at great expense or because they would cause the resource to be destroyed or removed. The application of the interim surplus criteria would include reviews at five-year intervals to consider the workability of the criteria in light of the multiple purposes served by the operation of the Colorado River system, including environmental maintenance. Based on those reviews, interim surplus criteria could be revised or eliminated as needed. If California fails to meet its water conservation and management goals throughout the stipulated term of implementation of the criteria (through 2016), the Secretary may choose to terminate the interim criteria and revert to the 70R strategy. Finally, after 2016, determinations of the availability of surplus will revert to the AOP process. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 27 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 32 of 1200 EXECUTIVE SUMMARY None of the resources assessed in the FEIS would experience a deterioration in condition such that the resource would be destroyed or removed as a result of implementation of interim surplus criteria or under the No Action Alternative. The Colorado River System may also reset at any time in the future, due to high inflows resulting in full reservoirs. There would be no construction of facilities needed to facilitate the Secretary's determination of surplus water under the criteria. Irretrievable commitment of natural resources means loss of production or use of resources as a result of a decision. It represents opportunities foregone for the period of time that a resource cannot be used. All of the resources assessed in the FEIS would continue to be available for production or use under any of the alternatives; however, application of the interim surplus criteria may result in a determination for any given year that surplus water is available from the Colorado River. That water could also have been determined to be surplus in the absence of interim surplus criteria through the AOP process. Although water is a renewable resource, the delivery of surplus water under all of the alternatives, including no action, would irretrievably commit (to beneficial consumptive uses) the water declared to be surplus, but authorized by the Law of the River. S.5 CONSULTATION AND COORDINATION Interior 17 the . of m Nove , 20 9 S.5.1 GENERAL PUBLIC INVOLVEMENT ept . D ACTIVITIES ber 2 nv Natiotod on consisted essentially of two j leading e the FEIS The public involvement programo Nava a hearings in and public rchiv and public review of the DEIS. phases: project scoping, cited 16864, 14S.5.1.1 PROJECT SCOPING No. In 1999, Reclamation conducted a public scoping process that featured public scoping meetings to inform interested parties of the purpose and need for the development of interim surplus criteria, and to obtain public comment to assist in identifying the scope of the proposed action and environmental issues to be addressed in the DEIS. The scoping meetings were held in June 1999 at Las Vegas, Nevada; Phoenix, Arizona; Ontario, California; and Salt Lake City, Utah. The meetings were announced in Federal Register notices on May 18, 1999 and May 28, 1999, on Reclamation’s Lower Colorado Region internet website, and by a press release on May 28, 1999. The press release was mailed not only to the media but also to hundreds of federal, state and local agencies, non-governmental organizations and private citizens known to have an interest in Colorado River operations. The public was asked to identify any concerns about development and implementation of the interim surplus criteria. Public comments in the form of letters to Reclamation (35 letters) and oral responses at the scoping meetings (eight presenters) expressed numerous concerns regarding the effect of the proposed interim surplus criteria on the future quantity of water available from the Colorado River, and other resource issues. Based on the scoping comments, COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 28 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 33 of 1200 EXECUTIVE SUMMARY Reclamation issued a Notice of Intent to prepare the DEIS in the Federal Register on December 7, 1999. Reclamation also discussed the development of the proposed interim surplus criteria with various agencies and groups at their own regular meetings or at meetings set up by Reclamation. Included were Indian Tribes and Indian Communities having allocations of Colorado River water, Basin States water resource departments, various water agencies within the States, contractors for federal hydropower, environmental groups water agencies of the United Mexican States (Mexico). The coordination activities with each agency or group are summarized below. Table S-2 lists the agencies and organizations that were invited to such meetings by letter, and/or met with Reclamation regarding interim surplus criteria on other occasions. S.5.1.2 PUBLIC REVIEW OF DEIS The DEIS was distributed to interested Federal, Tribal, State and Local entities and members of the general public for a 60-day review when it was filed with EPA on July 7, 2000, and announced in the Federal Register. The DEIS was sent to 407 interested parties on Reclamation’s mailing list, and a copy of the DEIS was made available for public viewing on Reclamation’s Lower Colorado Region web site. Reclamation conducted a public technical meeting at Las Vegas, Nevada on Augustor 2000, to nteri 15, provide information and answer questions regarding theof the I process 7 analysis modeling 201 for 9, pt. in the DEIS. Between August 21 and August 24, 2000, Reclamation conducted public . De ember 2 nv hearings on the DEIS in Ontario, California; Las Vegas, Nevada; Salt Lake City, Utah; Natio d on Nov o and Phoenix, Arizona. avaj ive in N rch ited 6864, a c review1 When the public - period closed on September 8, 2000, Reclamation received 68 o. 14 public which, along with Reclamation's responses, are comment letters from the N included in Volume III of the FEIS. Individual comments from the public resulted in technical and editorial changes to the document. These included a change in the baseline operating strategy, better definition of Tribal water rights and diversions, inclusion of the Basin States Alternative and refinements in descriptions of alternatives and operational modeling results. After the DEIS was completed and ready for public review and comment, Reclamation received the document “Interim Surplus Guidelines, Working Draft” from the Seven Basin States (Seven States Proposal). Reclamation made a preliminary review of the specific surplus criteria in the information presented by the basin states, and made a preliminary determination that the criteria were within the range of alternatives and impacts analyzed in the DEIS. After its review of the Seven States Proposal, Reclamation published it in the Federal Register of August 8, 2000, for review and consideration by the public during the public review period for the DEIS. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 29 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 34 of 1200 EXECUTIVE SUMMARY S.5.2 FEDERAL AGENCY COORDINATION S.5.2.1 NATIONAL PARK SERVICE NPS is a cooperating agency with Reclamation for the purpose of NEPA compliance for the interim surplus criteria, in recognition of its administration of national park and recreation areas along the Colorado River corridor. NPS staff participated in numerous meetings with Reclamation’s project evaluation team and participated in internal document reviews as sections of the DEIS were being prepared. This facilitated close coordination with the NPS regarding resources and facilities potentially effected and the nature of the effects. The NPS offices involved in these activities are those at the GCNRA, Grand Canyon National Park and the LMNRA, under the coordination of the office at the GCNRA. S.5.2.2 U.S. SECTION OF THE INTERNATIONAL BOUNDARY AND WATER COMMISSION The United States Section of the IBWC (USIBWC) is a cooperating agency with Reclamation for the purposes of NEPA compliance for the interim surplus criteria, in recognition of its administration of Treaty obligations with Mexico. As such, USIBWC staff participated in numerous meetings with Reclamation’s projecterior t evaluation team and Inwere being prepared. participated in internal document reviews as sections of thethe 017 f DEIS p . o er 29 2 This facilitated close coordination with the USIBWCtin developing ,information needed . De b for this FEIS and in Reclamation’s participation in the consultation with Mexico. The ion v Novem at USIBWC head office at El avajo N was directly involved. Paso, Texas ved on S.5.2.3 in N 4, archi ited OF INDIAN AFFAIRS c U.S. BUREAU 686 -1 o. 14 N The Bureau of Indian Affairs (BIA) administers programs to promote Tribal economic opportunity, and to protect and improve Indian Trust Assets. The BIA assisted Reclamation with the Tribal consultation, and generally served in an advisory capacity to the Tribes. Through letters of comment on the DEIS, the BIA further amplified Tribal concerns regarding Colorado River operations and the interim surplus criteria. S.5.2.4 U.S. FISH AND WILDLIFE SERVICE INCLUDING ENDANGERED SPECIES ACT COMPLIANCE Under Section 7(a)(2) of the Endangered Species Act (ESA), 16 U.S.C. δ 1536 (a)(2), each Federal agency must, in consultation with the Secretary (either the Secretary of Commerce through the National Marine Fisheries Service or the Secretary of the Interior through the Fish and Wildlife Service), insure that any discretionary action authorized, funded, or carried out by the agency is not likely to jeopardize the continued existence of any listed species or result in the destruction or adverse modification of designated critical habitat. To assist agencies in complying with the requirements of Section 7(a)(2), ESA’s implementing regulations set out a detailed consultation process COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 30 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 35 of 1200 EXECUTIVE SUMMARY for determining the biological impacts of a proposed discretionary activity. The consultation process is described in regulations promulgated at 50 C.F.R. δ 402. Adoption of specific interim surplus criteria by the Secretary is a discretionary federal action and is therefore subject to compliance with the ESA. On May 22, 2000, Reclamation provided the Service a memorandum identifying listed or proposed species and designated critical habitat that may be present in the action area. The Service provided a response to Reclamation on June 5, 2000, which concurred with Reclamation’s list and added two species: Bald Eagle and Desert Pupfish. This information was used to assess potential effects of the proposed interim surplus criteria. Reclamation prepared a biological assessment (BA) which addresses the effects of both interim surplus criteria and the California water transfers, to reduce the consultation time frame on these two independent operational actions on the lower Colorado River. The BA and memorandum requesting formal consultation were mailed to the Service on August 31, 2000. The action area for the BA identified above is the 100-year floodplain of the Colorado River to the SIB and the full pool elevations of Lakes Mead, Mohave and Havasu. Implementation of the interim surplus criteria is not expected to effect any listed species upriver of Lake Mead (full pool elevation) nor impact implementationior any provisions ter of he In the2United States, of the existing BO on the operation of Glen Canyon Dam. t 017 f Within pt. o to r 29, any listed species implementation of interim surplus criteria is notDe v. anticipatedbe effect o the N Colorado in areas beyond the 100-year floodplain iofn lowerovem River and the full pool Nat d on elevations of lakes Mead,Navajo and Havasu. Consultation with the Service is in Mohave hive d in 6consultation will be identified in the ROD. progress and the iresults of the 4, arc c te 168 . 14- of the effects of adopting interim surplus criteria on listed No Preliminary evaluations species which may be present in the river corridor below Glen Canyon Dam led to the conclusion that there would be no affect. More recent output, resulting from refinement of the model used to predict future dam operations and riverflows, indicated that there would be a minor change in the frequency with which flows recommended by the 1995 biological opinion would be triggered, but that such changes would not adversely affect any listed species between Glen Canyon Dam and Lake Mead. Reclamation is consulting with the Service on these changes. Reclamation is also consulting with the Service regarding special status species in Mexico. To facilitate consultation, Reclamation prepared a supplemental biological assessment (BA) addressing the potential effects of interim surplus criteria along the Colorado River corridor in Mexico from the SIB to the Sea of Cortez. Consultation is in progress and the results of the consultation will be identified in the ROD. S.5.2.5 NATIONAL MARINE FISHERIES SERVICE The National Marine Fisheries Service (NMFS) administers programs that support the domestic and international conservation and management of living marine resources. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 31 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 36 of 1200 EXECUTIVE SUMMARY Under Section 7(a)(2) of the ESA, NMFS is the responsible Federal agency for consultation on special-status marine species. Reclamation consulted with NMFS regarding the special-status fish at the upper end of the Sea of Cortez. The consultation was facilitated by a BA supplementing the BA described in Section S.5.2.4 on the Colorado River corridor in Mexico. Consultation is in progress and the results of the consultation will be identified in the ROD. S.5.2.6 NATIONAL HISTORIC PRESERVATION ACT COMPLIANCE Section 106 of the National Historic Preservation Act (NHPA) of 1966, as amended, requires all Federal agencies to take into account the effects of their actions on historic properties, and to afford the Advisory Council on Historic Preservation (Council) a reasonable opportunity to comment when an action will have an effect on historic properties. The Council’s recommended approach for consultation for the Protection of Historic Properties is found at 36 CFR 800 (FR Vol. 64, No. 95, May 18, 1999, pages 27071-27084). The first step of the Section 106 process, as set forth at 36 CFR 800.3(a), is for the Agency Official to determine whether the proposed Federal action is an undertaking as defined in §800.16(y) and, if so, whether it is a type of activity that has the potential to cause effects to historic properties. Reclamation has determined erior Intthe definition of development and implementation of interim surplus criteria he f t meets9 2017 pt. o to effect, historic an undertaking, but an undertaking that is withoute . D potentialber 2 n vthe rationale for its decision are em properties. Reclamation’s determinationo Nati and on Nov documented in Section 3.13 ofajo FEIS.ved 36 CFR 800.3(a)(1), if the undertaking Nav the hi Per does not have theted in to64, areffects on historic properties, the Agency potential cause c ci 168 Official has no further obligations under Section 106 or this part, Reclamation has . 14- to take into account the effects of the development and No fulfilled its responsibilities implementation of interim surplus criteria on historic properties. The Nevada State Historic Preservation Officer (SHPO) submitted written comments on the cultural resources section of the DEIS. The SHPO has indicated they do not agree with Reclamation’s position in the DEIS that development and implementation of interim surplus criteria is an undertaking without potential to affect historic properties, and so complying with the consultation requirements of the NHPA is not necessary. The Nevada SHPO has stated that their opportunity to comment on effects to historic properties has been precluded by Reclamation and the Department’s finding, and have asked that the matter be referred to the Council. Under the implementing regulations for Section 106, when there is a disagreement between an agency and a SHPO concerning the effect of an undertaking, the matter must be referred to the Council for comment and resolution. Reclamation believes the Council will agree with the Nevada SHPO that Section 106 compliance is necessary for this proposed action. Reclamation’s position is that this is not an action requiring Section 106 compliance, but more appropriately falls under Section 110 of COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 32 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 37 of 1200 EXECUTIVE SUMMARY the NHPA. Reclamation has prepared a memorandum discussing this issue and has forwarded it to the Council for review and further consultation. S.5.3 TRIBAL CONSULTATION Reclamation has been coordinating river operations with the Indian Tribes and communities who have entitlements to or contracts for Colorado River water, and those that may be affected by the proposed action. Representatives of various Tribes attended the scoping meetings in May 1999, and some provided Reclamation with written comments on the proposal for interim surplus criteria. Beginning in May 1999, Reclamation has had numerous meetings with the various Tribes who have an interest in the implementation of the interim surplus criteria. The Tribes and communities fall generally into four groups: 1) the Colorado River Basin Indian Tribes (Ten Tribes Partnership) who have diversion rights from the Colorado River main stream and various tributaries; 2) the Tribes and Communities of central Arizona; 3) the Tribes in the Coachella Valley Consortium of Mission Indians; and 4) other Tribes or Indian Communities who do not have a Colorado River water entitlement but nevertheless have an interest in the availability and distribution of Colorado River water. The individual Tribes and Indian Communities in each of these groups are listed on Table S-2 at the end of this chapter. ior Inter rights be A primary concern of the Ten Tribes Partnership was thatf Tribal water 017 the t. each Tribe 2 pforo er 29,be included in clearly acknowledged and that the diversion point(s) . De b ion v No tribal the operational model so as to more accurately reflect vem diversions in the at on jo N modeling. Other concerns included overreliance on unused Tribal water allocations Nava archived in by non-Tribal diverters, and Lake Powell water level fluctuations with respect to cited 16864, resort development 14opportunity. Reclamation provided financial assistance to the No. Ten Tribes Partnership to assist the Tribes in cataloging their Colorado River depletion rights and conducting an active coordination process with Reclamation in connection with the interim surplus criteria. Using information provided by the Tribes, Reclamation added the diversion points to the model for the FEIS. S.5.4 STATE AND LOCAL WATER AND POWER AGENCIES COORDINATION Since the May 18, 1999 Federal Register notice announcing the development of interim surplus criteria, Reclamation has had various discussions with state and local water and power agencies regarding the proposed interim surplus criteria. However, the development of surplus criteria has been the subject of discussions for many years prior to 1999. Reclamation meets regularly with representatives of the Basin States, Indian Tribes and communities, environmental organizations, and other stakeholders as part of the Colorado River Management Work Group. Reclamation coordinates the development of the Annual Operating Plan (AOP) for the Colorado River system through this group as required by federal law. It was through such coordination actions that Reclamation originally presented the alternative surplus strategies. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 33 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 38 of 1200 EXECUTIVE SUMMARY The Basin States provided Reclamation with projections of the future depletions of the Colorado River water anticipated by water agencies in each state. The Upper Colorado River Commission compiled Upper Basin depletions, and the Lower Division states compiled their respective depletions. The projections were used as input to Reclamation’s operational modeling analysis. Reclamation also conducted coordination with water agencies in southern California regarding the environmental documentation being prepared for various components of California’s Colorado River Water Use Plan. In the early summer of 2000, the seven Basin States acting as a group, independently from Reclamation, formulated the Seven States Proposal for interim surplus criteria which they provided to Reclamation after the DEIS was prepared. Letters of comment on the DEIS from some of the Basin States contained additional commentary on the draft proposal. S.5.5 NON-GOVERNMENTAL ORGANIZATIONS COORDINATION Several environmental organizations have expressed interest in the project and have attended one or more public and independent meetings with Reclamation. The Pacific Institute for Studies in Development, Environment and Security (PacificrInstitute), terio representing a consortium of environmental organizations, the In an interim surplus submitted 017 2 of criteria proposal to Reclamation in February 2000. pt. proposal included an additional e The ber 29, .D em allocation of water to Mexico for environmental purposes. The Pacific Institute’s ion v Natrole d on Novother environmental groups interest in the project and coordinating ve among the vajo in Na 4, archi contributed to theted i coordination with Reclamation by various other non-governmental 6 6 organizations. c addition, 8 In 14-1 through the Colorado River Management Work Group, and . Reclamation worked with various non-governmental organizations other mechanisms, No during the NEPA process. Specifically, Reclamation met with members of the organizations noted in Table S-2 at their request to discuss environmental and technical issues. S.5.6 MEXICO CONSULTATION Pursuant to an international agreement for mandatory reciprocal consultations, the United States section of the IBWC (USIBWC) is consulting with Mexico regarding the proposed interim surplus criteria. Reclamation has assisted USIBWC in conducting this consultation by providing information on the proposed interim surplus criteria and by participating in briefings with the Mexico Section of the IBWC and the Mexico National Water Commission. Meetings with representatives of Mexico were conducted in April and May 2000, at which representatives of Mexico provided their concerns regarding the potential effects of the interim surplus criteria. Coordination with Mexico during the DEIS review phase has consisted of several letters from the government of Mexico and public agencies in Mexico, which are reproduced in Volume III of the DEIS. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 34 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 39 of 1200 EXECUTIVE SUMMARY Discussion with Mexico took place on November 14, 2000 concerning comments from Mexico. There was understanding that the consultation with Mexico through IBWC in the form of technical working groups will continue a forum for technical discussion to carry out, in the context of international comity, joint cooperation projects in support of the Colorado River riparian ecology to the Gulf of California that could have a benefit to the United States and Mexico. Executive Order 12114 instructs Federal agencies to investigate the effects of Federal actions in other countries. Reclamation has analyzed and documented the effects of the proposed interim surplus criteria on natural resources in Mexico. This analysis will provide an analytical tool for identifying those potential impacts that extend across the international border and affect Mexico’s natural and physical environment. This approach is fully consistent with CEQ guidance on NEPA analyses for transboundary impacts, dated July 1, 1997. S.5.7 SUMMARY OF COORDINATION CONTACTS Table S-2 lists the agencies and organizations with which Reclamation coordinated through meetings and other personal contacts during the scoping and preparation period of this FEIS. ior Inter 17 S.5.8 FEDERAL REGISTER NOTICES 0 f the pt. o er 29, 2 e v. D Table S-3 lists the Federal Register Notices issued to inform the public about the emb tion n aalternativesNovthe preparation and availability formulation of interim surplus ajo N v criteria ed o and of the DEIS. In addition N the notices issued, notices will be provided following the in to a 4, archiv cited to 86 publication of this FEIS16announce its availability and the Secretary’s ROD based on 14this FEIS. No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 35 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 40 of 1200 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. The probability of Lake Powell being full in 2016 is 27%. 3 Reservoir water levels exhibit a gradual declining trend during the interim surplus criteria period as a result of increasing Upper Division states consumptive use. The median water surface elevation in 2016 is 3665 feet msl. Baseline Conditions/No Action 2 Basin States Flood Control Six States California Shortage Protection 3664 feet msl 3664 feet msl 3664 feet msl 3660 feet msl 3659 feet msl Median Elevations in 2016 for each of the alternatives are as follows: Effects of Alternatives 37 Flows downstream of Hoover Dam are governed by downstream demand or Hoover Dam flood control releases. Flows downstream of Glen Canyon Dam would be managed in accordance with the 1995 Glen Canyon Dam EIS and the 1996 ROD. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Glen Canyon and Hoover Dam releases and flows downstream of Lake Mead. River Flows continue to decline, although at a lower rate, due to less frequent Lower Basin surplus deliveries. After 2016, median levels stabilize, then rise and fall slightly, due to 602(a) storage requirements and less frequent equalization releases. Other alternatives: Flows below Glen Canyon Dam would be similar to baseline conditions. Flows from Hoover Dam to Parker Dam would be moderately higher until 2016 because of surplus deliveries. After 2016, flows would be similar to baseline conditions. After 2016, median surface elevations continue to decline. By about 2035, all alternatives converge to elevations similar to baseline conditions. Flood Control Alternative: Similar to baseline conditions. After 2016, Lake Powell water levels under all five alternatives tend to stabilize similar to baseline conditions. Water levels under the Basin States, Flood Control, Six States, California and Shortage Protection alternatives tend to converge with the baseline conditions by about year 2030. ior Inter 17 e of th 29, 20 pt. . De ember v ation on NovMedian Elevations in 2016 for each of the alternatives are as Lake Mead Water Surface Reservoir water levels exhibit a gradual N Elevations declining trend during the interim d vajo Lower Basin surplus criteria follows: e consumptive Na in exceeding long-termhiv The median Potential changes in Lake Mead waterd period as a result of rc 1143 feet msl a Basin States surface elevations. 1162 feet msl cite use16864, ininflow. is 1162 feet Flood Control water 1146 feet msl 4- surface elevation 2016 Six States 1 msl. 1131 feet msl California No. After 2016, median water surface elevations 1130 feet msl Shortage Protection Potential changes in Lake Powell water surface elevations. Lake Powell Water Surface Elevations Reservoirs Elevations and River Flows Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 41 of 1200 2002 through 2016 2017 through 2050 2002 through 2016 2017 through 2050 2002 through 2016 2017 through 2050 2002 through 2016 2017 through 2050 Normal: Surplus: Shortage: Normal: 0% 0% 47% 21% 100% 100% Baseline Conditions/No Action 2 Other Alternatives: Greater probability of surplus through 2016. The probability is similar to baseline conditions from 2017 through 2050. Deliveries less than the normal apportionment (4.4 mafy) do not occur under the alternatives at any time through 2050. Flood Control Alternative: Similar to baseline conditions. Effects of Alternatives 100% 100% 2002 through 2016 2017 through 2050 2002 through 2016 2016 through 2050 2002 through 2016 2017 through 2050 Normal: Surplus: Shortage: 38 < 4% 50% Shortage: 2002 through 2016 2017 through 2050 0% 0% 26% 19% 47% 21% 50% >96% 50% 2002 through 2016 2017 through 2050 Surplus: 2017 through 2050 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Probabilities of meeting Treaty delivery obligations. Mexico Treaty Delivery Probabilities of normal, surplus and 4 shortage conditions. 4 Arizona Water Supply The Flood Control Alternative would provide slightly higher (1%) probabilities of surplus than under baseline conditions through 2016. The rest of the alternatives provide slightly lower (3% to 7%) probabilities of surplus through 2016 and about the same level as baseline through 2050. Deliveries less than the treaty apportionment (1.5 mafy) do not occur under the alternatives at any time through 2050. Other Alternatives: Greater probability of surplus through 2015; same as baseline from 2017 to 2050. The probability of shortage condition deliveries is slightly higher (7% to 14%) for the alternatives through 2016. From 2017 to 2050, the probability of shortage condition deliveries is higher (3% to 5%) under the alternatives. Flood Control Alternative: Similar to baseline conditions. ior Inter 17 of surplus through 2016 Probabilities of normal, surplus and Other Alternatives: Greater probability he shortage conditions. under the California and Shortage Protection alternatives and of tlower (26%) under0 Basin States and Six States Surplus: 2002 through 2016 29% t. 2 ,2 2017 through 2050 21% e D p slightly berThe 9 theof surplus under the alternatives is alternatives. probability v. em to tion < n Novabout the same as baseline from 2017the 2050. The probability Shortage: 2002 through 2016 4% of shortage condition deliveries under alternatives is slightly jo Na2050ed o50% 2017 through higher (7% to 14%) through 2016. From 2017 to 2050, the Nava archiv probability of shortages under the alternatives is similar to in baseline conditions. cited 16864, 14 No. Normal: 2002 through 2016 96% Nevada Water Supply Flood Control Alternative: Similar to baseline conditions. Probabilities of normal, surplus and 4 shortage conditions. California Water Supply Water Supply Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 42 of 1200 Increased potential for lower Lake Mead levels and increased inflow channel lengths under baseline projections could increase potential of elevated contaminant concentrations. Baseline projections assume compliance with numeric criteria along the river. The Basin States are committed to meeting the numeric criteria. Baseline Conditions/No Action 2 The alternatives, except the Flood Control Alternative, result in slightly increased potential for increased contaminant concentrations in Boulder Basin, due to greater potential for lower Lake Mead levels than under baseline conditions. Modeling indicates potential for slight reductions in salinity under each alternative as compared to baseline. Effects of Alternatives 39 Species are adapted to fluctuating reservoir levels. Therefore, increased potential for lower Lake Mead and Lake Powell surface levels is not expected to adversely affect aquatic species. Average annual probability from 2002 through 2016: Davis Dam 9% Parker Dam 10% Average annual probability from 2017 through 2050: Davis Dam 5% Parker Dam 6% COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Potential effects on Lake Mead and Lake Powell fisheries and associated aquatic habitat. Lake Habitat and Sport Fisheries Aquatic Resources Probability of damaging flows below Davis and Parker Dams. Flooding Downstream of Hoover Dam Glen Canyon Dam. Compared with baseline conditions, slightly increased potential for higher reservoir levels under the Flood Control Alternative and increased potential for lower reservoir levels under the other alternatives would not be expected to result in substantial changes to lake habitat. The probability under other alternatives is slightly less than under baseline conditions. The probability under the Flood Control Alternative is slightly greater than under baseline conditions. ior Inter 17 Flow-Related Issues the 2 ofprobability 29, the 0 t. Beach/Habitat-Building Flow The average annual probability of BHBF r under during the is typically less than Dep Thembaseline conditionsalternativesinterim period, and Releases releases is 16% through 2016 and 14% from under be v. e tion n Novconverges with baseline conditions thereafter. Probability of BHBF release conditions 2017 through 2050. Na d o from Glen Canyon Dam. jo Nava archive in Low Steady Summer Flows annual t requisite864 probability flows is 38% under baseline under the during the is seven less and cifored The averagelow,steady summerof conditions The probability conditionsalternativesfirsttypicallyyearsthan for 6 2016 and 62% from 2017 through Probability of requisite conditions 4-1 similar to or slightly greater than under baseline conditions low steady summer flow releaseso. 1 through from 2050. thereafter. N Contaminant concentrations in Boulder Basin of Lake Mead, in proximity to the SNWS intakes at Saddle Island. Lake Mead Water Quality and Las Vegas Water Supply Potential change in salinity below Hoover Dam. Colorado River Salinity Water Quality Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 43 of 1200 Under baseline conditions, increased potential over time for lower reservoir levels could increase potential for development of temporary riparian habitat at the deltas, which would benefit special-status wildlife species that utilize such habitat. Under baseline conditions, special-status plant species would continue to be affected by fluctuating water levels, which would periodically expose and inundate areas where the plants occur. Baseline Conditions/No Action 2 The Flood Control Alternative would have slightly lower potential, while the other alternatives would have increased potential, for lower reservoir elevations and associated potential increases in delta habitat. Although reservoir elevations would differ, the effects of all alternatives would be similar to baseline conditions. Effects of Alternatives 40 Baseline condition projections indicate an increased potential for the occurrence of lower Lake Mead and Lake Powell reservoir levels, which may result in potential increases in navigation hazards and decreased safe boating capacity (due to decreased reservoir surface area). operating range that some existing facilities may be able to accommodate. Such occurrence would likely result in modification of facilities to accommodate lower surface elevations. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Potential effects on reservoir boating that may result from changes in Lake Mead and Lake Powell surface elevations. Reservoir Boating/Navigation recreation facilities from changes in Lake Mead and Lake Powell surface elevations. The Flood Control Alternative has slightly lower potential, and each of the other alternatives have higher potential, for each of navigation hazards and reduced carrying capacity. ior Inter 17 e of th 29, 20 pt. er . De Changes in potential for lower reservoir levels under the various Special-Status Fish Under baseline conditions, increased potential n v have ovalternatives would not change potential for effects. emb tio for lower elevations is not expected to N Potential effects of Lake Mead and jo Na ved different effects on special-status species fish on aoccur at present. Lake Powell reservoir level changes v than Na that on special-status fish species. in those 4, archi Recreation cited 1686 Reservoir Marinas/Boat Launching 14Baseline condition projections indicate The Flood Control Alternative has a slightly decreased potential No. increased potential for reservoir levels lower for lower reservoir levels; each of the other alternatives have Potential effects on shoreline than those considered within the normal increased potential for lower levels and necessary relocations. Potential effects on special-status wildlife species associated primarily with potential effects on riparian habitat at the Lake Mead and Virgin River deltas, and the lower Grand Canyon. Special-Status Wildlife Potential effects on special-status plants for areas influenced by Lake Powell and Lake Mead water levels. Special-Status Plants Special-Status Species Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 44 of 1200 Baseline condition projections indicate increased relocation costs associated with future increased potential for lower reservoir levels. Potential effects on sport fisheries are minimal under baseline conditions. Boaters may have reduced take-out opportunities due to increased potential for lower reservoir surface elevations. Baseline Conditions/No Action 2 The Flood Control Alternative is similar to baseline conditions. Other alternatives have greater potential for increased relocation costs, based on an average cost per foot associated with relocating facilities. Changes in reservoir elevations under each of the alternatives would not be expected to adversely affect sport fisheries or fishing in either reservoir. The Flood Control Alternative has lower potential, and each of the other alternatives have increased potential, for reduced take-out opportunities resulting from lower reservoir elevations. Effects of Alternatives 41 Future lower average Lake Mead water levels would require more energy and increased pumping costs for the SNWS intake. 4685 GWh through 2016; 3903 GWh from 2017 through 2050. production: COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Potential change in the cost of power to pump Lake Mead water through the SNWS. Pumping Power Needs for SNWS Increased costs associated with relocating shoreline facilities to remain in operation at lower reservoir elevations. Basin States Flood Control Six States California Shortage Protection $229,395 $ 32,685 $214,779 $544,843 $532,635 The increase over baseline conditions of annual pumping costs for each alternative follows: production is from 51 to 127 GWh less. ior Inter 17 e of th 29, 20 pt. . De ember v Energy Resources ation on Nov N average annual Hydroelectric Power Production Glen Canyonajo The Flood Control Alternative is similar to baseline conditions. v Powerplanthived energy production: Na c Potential for changes in energy Average annual power production under the other alternatives in ar production at Glen Canyon and ited 4532 GWh64, 2016; 4086 GWh from 2017 is greater than under baseline conditions for the first six to eight through c 6 2050. Hoover powerplants. through 8 years, then is less for the remaining years. Averaged from 14-1 Powerplant average annual energy 2002 to 2050, Glen Canyon annual power production is from 12 o. Hoover N to 30 GWh less than baseline conditions, while Hoover power Recreation Facilities Relocation Costs Potential effects on sport fishing in Lake Mead and Lake Powell. Reservoir Sport Fishing Potential effects on river boating at Lake Powell and Lake Mead inflow areas. River and Whitewater Boating Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 45 of 1200 Future lower average Lake Powell water levels would require more energy and increased pumping costs for the Navajo Generating Station and the City of Page. Intake Energy Requirements at Lake Powell 2 The increase over baseline conditions of annual pumping costs for each alternative follows: Navajo Generating Station $2,216 Basin States $ 0 Flood Control $2,129 Six States $4,651 California $4,660 Shortage Protection Effects of Alternatives 42 Not significant due to past water level fluctuations. Impacts have already occurred. Increased probability of temporary degradation in visual attractiveness of shoreline vistas resulting from increasing potential for lower water levels in Lake Mead and Lake Powell. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Effects on Historic Properties in Operational Zone of Reservoir and River Reaches. Cultural Resources Potential effects of lower reservoir elevations on scenic quality. Visual Attractiveness of Reservoir Scenery, Lake Mead and Lake Powell Visual Resources Not significant due to past water level fluctuations. Impacts have already occurred. Other alternatives: Higher probability of degradation of visual attractiveness through 2016 due to accelerated decline of minimum reservoir levels. Flood Control Alternative: Same as baseline conditions. City of Page Basin States Flood Control Six States California Shortage Protection ior $ 529 Inter 17 $ 0 e of th 29, 20 $ 508 $1,110 pt. $1,112 . De ember v Air Quality tion n Nov a Fugitive Dust Emissions from Increased potential for lower reservoir levels Slightly decreased shoreline exposure under Flood Control ajo N ived o Nav arc for Exposed Reservoir Shoreline would increase potential h shoreline exposure Alternative would lower fugitive dust emission potential. Other in baseline , 4would be minimal due to low increased fugitive have slightly increased changes in Potential for fugitive dust emissionse it d underemissions conditions. Increases in fugitive alternatives woulddust emissions. Minimalpotential for areac 86 from shoreline exposure at Lake Mead dust 6 4-1 potential of shoreline. emission wide fugitive dust emissions would be expected. 1 and Lake Powell. No. Potential change in the cost of power to pump Lake Powell water to the Navajo Generating Station and the City of Page. Baseline Conditions/No Action Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 46 of 1200 No effects are anticipated. There is a probability of shortages of CAP priority water for tribes in central Arizona. The water available to members of Ten Tribes Partnership would not be affected by future changes under baseline conditions. Baseline Conditions/No Action 2 No effects anticipated. Greater probability of shortages of CAP priority water for tribes in central Arizona under all alternatives with the exception of the Flood Control Alternative. No effect on water available to members of Ten Tribes Partnership. Effects of Alternatives Under the Basin States Alternative there would be no effect on desert pupfish, Vaquita, Yuma clapper rail, California black rail, Clarks grebe; and there is not likely to be any adverse affect on totoaba, Southwestern willow flycatcher, Yellow-billed cuckoo, Elf owl or Bell's vireo. Other alternatives: Small reduction in probability of excess flows. 43 Effects identified are based on probabilities developed through modeling of possible future conditions through 2050, discussed in detail in Chapter 3. In general, the differences between the alternatives and baseline conditions would be greatest at or near 2016, the year in which the interim surplus criteria would terminate. Lake Powell is considered to be essentially full when the lake elevation reaches 3695 feet msl (5 feet below the top of the spillway gates). Probabilities of shortage are based on the modeling assumption of protecting a Lake Mead elevation of 1083 feet msl. There are no established shortage criteria for the operation of Lake Mead. Probability of excess flows below Morelos Dam would gradually decline. would gradually decline under baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3. 4. 1. 2. Potential Effects on Species and Habitat in Mexico Amount of excess flow that may reach the Colorado River delta. ior Inter 17 Transboundary Effects the ofFlood Control9, 20 would provide slightly higher (1%) . Normal: 2002 through 2016 100% ept The Treaty Water Delivery Obligations er 2 Alternative .D 2017 through 2050 100% probabilities of surplus than under baseline conditions 2016. v mbof the alternatives provide slightly lower (3% to 7%) Probabilities of meeting Treaty delivery e tion 26% obligations Na2016 d on NovThe rest of surpluses through 2016 and about the same Surplus: 2002 through probabilities ajo 2050 level as baseline through 2050. Deliveries less than the treaty Nav2016 throughhive 19% in apportionment (1.5 mafy) do not occur under the alternatives at d Shortage: 62002 through 2016 , arc 4 0% any time through 2050. cite 168 2017 through 2050 0% 4. 1 Probability of excess flows below Morelos Dam Flood Control Alternative: Similar to baseline. Flow Below Morelos Dam No Exposure of Minority or Low Income Communities to Health or Environmental Hazards Environmental Justice Effects on water supply for Indian Tribes and Communities Indian Trust Assets Resource/Issue Table S-1 1 Summary of Potential Effects of Implementing Interim Surplus Criteria EXECUTIVE SUMMARY Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 47 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 48 of 1200 EXECUTIVE SUMMARY Table S-2 Participants with Reclamation Regarding the Interim Surplus Criteria Environmental Impact Statement Process Agency or Organization Invited to or Requesting Meetings Meetings Federal Agencies National Park Service – Cooperating Agency Various plan formulation and evaluation meetings U. S. Section of the International Boundary and Water Commission – Cooperating Agency Various plan formulation and evaluation meetings; Briefings for Mexico Bureau of Indian Affairs 5/26/99, 12/15/99, 1/21/00, 2/24/00, 8/30/00 Environmental Protection Agency 6/15/99, 8/30/00 Fish And Wildlife Service Geological Survey Various Consultation Meetings on ESA Compliance Consultation on Special Status Species in the Sea of Cortez, 10/12/00 6/15/99, 8/15/00 Western Area Power Administration 6/15/99, 8/15/00 National Marine Fisheries Service ior Inter 17 0 f the pt. o er 29, 2 Chemehuevi Tribe (10 Tribes member) 5/26/99, 6/15/99, 11/16/1999, 12/15/99, e v. D & 25/00,b 2/24 m 8/4/00 ation on Nove N Cocopah Indian Tribe (10 Tribes member) vajo ed 5/26/99, 6/15/99, 111/16/1999, 2/15/99, in Na 4, archiv 2/24 & 25/00, 8/3/00 d cite 1686 Colorado River Indian Tribes - Tribes member) 5/26/99, 6/15/99, 11/16/1999, 12/15/99, 14 (10 No. 2/24 & 25/00, 8/4/00 Tribal Coordination – Ten Tribes Partnership Fort Mojave Indian Tribe (10 Tribes member) 5/26/99, 6/15/99, 11/16/1999, 12/15/99, 2/24 & 25/00, 8/2/00 Jicarilla Apache Tribe (10 Tribes member) 5/26/99, 11/16/1999, 12/15/99, 2/24 & 25/00 Navajo Nation (10 Tribes member) 5/26/99, 11/16/1999, 12/15/99, 2/24 & 25/00, 9/27/00, 8/3/00 Northern Ute Tribe (10 Tribes member) 5/26/99, 11/16/1999, 12/15/99, 2/24 & 25/00, 8/17/00 Quechan Indian Tribe (10 Tribes member) 5/26/99, 6/15/99, 11/16/1999, 12/15/99, 2/24 & 25/00, 8/2/00 Southern Ute Indian Tribe (10 Tribes member) 5/26/99, 11/16/1999, 12/15/99, 2/24 & 2500 Ute Mountain Ute Tribe (10 Tribes member) 5/26/99, 11/16/1999, 12/15/99, 2/24 & 25/00, 8/3/00 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 44 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 49 of 1200 EXECUTIVE SUMMARY Table S-2 Participants with Reclamation Regarding the Interim Surplus Criteria Environmental Impact Statement Process Agency or Organization Invited to or Requesting Meetings Meetings Tribal Coordination –Tribes And Communities In Central Arizona Ak-Chin Indian Community 5/26/99, 6/15/99, 1/21/00, 8/3/00 Mojave-Apache Tribe 5/26/99, 1/21/00, 8/3/00 Gila River Indian Community 5/26/99, 6/15/99, 1/21/00, 8/3/00 Pasqua-Yaqui Tribe 5/26/99, 1/21/00 Salt River Pima-Maricopa Indian Community 5/26/99, 6/15/99, 1/21/00 San Carlos Indian Tribe 5/26/99, 6/15/99, 1/21/00, 8/3/00 Tohono O’Odham Tribe 5/26/99, 6/15/99, 1/21/00, 8/15/00, 8/3/00 Tonto Apache Tribe 5/26/99, 6/15/99, 1/21/00, 8/4/00 Yavapai-Apache Indian Community 5/26/99, 6/15/99, 1/21/00, 8/3/00 Yavapai-Prescott Indian Tribe 5/26/99, 6/15/99, 1/21/00 Morongo Band of Mission Indians 8/30/00 Torres-Martinez Desert Cahuilla Tribe 1/21/00, 8/30/00 Twenty-Nine Palms Band of Mission Indians [Contact attempted; DEIS sent] ior Inter 17 0 f the pt. o er 29, 2 e Indians Tribal Coordination – Coachella Valley Consortium Of.Mission v D v mb ation on8/30/00,e9/6/00 No Agua Caliente Band of Cahuilla Indians jo N va ed in Na rchiv Augustine Band of Mission Indians 64, a [Contact attempted; DEIS sent] ited 68 c 4-1 Cabazon Band of Mission1 (Contact attempted; DEIS sent] No. Indians Tribal Coordination – Other Tribes Havasupai Indian Tribe 6/15/99, 5/26/99, 1/21/00 Hopi Tribe 6/15/99, 5/26/99, 1/21/00, 8/4/00 Hualapai Nation 6/15/99, 5/26/99, 1/21/00, 8/3/00 Kaibab Paiute Tribe 8/3/00 San Juan Southern Paiute Tribe 8/3/00 San Luis Rey Indian Water Authority 8/16/00 Zuni Indian Tribe 8/3/00 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 45 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 50 of 1200 EXECUTIVE SUMMARY Table S-2 Participants with Reclamation Regarding the Interim Surplus Criteria Environmental Impact Statement Process Agency or Organization Invited to or Requesting Meetings Meetings State and Local Water and Power Agencies Arizona Department of Water Resources 6/15/99, 12/16/1999, Central Arizona Water Conservancy District 6/15/99, 8/15/00 Coachella Valley Water District 6/15/99, 6/6/00, 8/15/00 Colorado River Board of California 6/15/99, 12/16/1999, 6/6/00, 8/15/00,11/14/00 Colorado River Commission of Nevada 6/15/99, 12/16/1999, Colorado River Water Conservation District 8/15/00 Colorado Water Conservation Board 12/16/99, 8/15/00 Utah Division of Water Resources 12/16/99, Imperial Irrigation District 6/15/99, 6/6/00, 8/15/00, 11/14/00 Las Vegas Valley Water District 6/22/99 Upper Colorado River Commission 6/15/99, 8/15/00 San Diego County Water Authority 8/15/00 Southern Nevada Water Authority 12/16/99, 8/15/00 ior Inter 17 f the 9, 0 Metropolitan Water District, California 6/15/99,o pt. 6/6/00, 8/15/00 2 De er 2 n v. 12/16/99,mb New Mexico Interstate Stream Commission atio Nove 8/15/00 ajo N ived on Nav Office of the State Engineer, iWyoming 12/16/99, 8/15/00 d n 64, arch te ciResources68 Parker Valley Natural 12/16/99, -1 Conservation D. o. 14 N Non-Governmental Agencies Center for Biodiversity 12/15/99, 6/8/00 Defenders of Wildlife 12/15/99, 8/15/00 Environmental Defense 12/15/99, 8/15/00 Glen Canyon Action Network 8/22/00 Pacific Institute 12/15/99, 8/15/00 Southwest Rivers 12/15/99, 8/15/00 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 46 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 51 of 1200 EXECUTIVE SUMMARY Table S-2 Participants with Reclamation Regarding the Interim Surplus Criteria Environmental Impact Statement Process Agency or Organization Invited to or Requesting Meetings Meetings International Agencies International Boundary and Water Commission, Mexico Section 4/12/00, 5/11 & 12/2000, 9/30/00, 11/9/00, 11/14/00 National Water Commission, Mexico 4/12/00, 5/11 & 12/2000, 9/30/00, 11/9/00, 11/14/00 National Institute of Ecology, Mexico 4/12/00, 9/30/00, 11/9/00, 11/14/00 Secretariat of Environment, Natural Resources and Fish, Mexico 9/30/00, 11/14/00 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 47 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 52 of 1200 Table S-3 Federal Register Notices Regarding Interim Surplus Criteria Notice Title Volume 64, No. 95, Page 27008, May 18, 1999 Intent to Solicit Comments on the Development of Surplus Criteria for Management of the Colorado River and to Initiate NEPA Process. Volume 64, No. 103, Page 29068, May 28, 1999 Public Meetings on the Development of Surplus Criteria for Management of the Colorado River and to Initiate NEPA Process Volume 64, No. 234, Page 68373, December 7, 1999 Colorado River Interim Surplus Criteria; Notice of Intent to Prepare an Environmental Impact Statement Volume 65, No. 131, Page 68373, July 7, 2000 Notice of availability of a draft environmental impact statement and public hearings for the propose adoption of Colorado River Interim Surplus Criteria Volume 65, No. 149, Page 47516, August 2, 2000 Notice of revised dates for public hearings on the proposed adoption of Colorado River Interim Surplus Criteria Volume 65, No. 153, Page 48531, August 8, 2000 Notice of public availability of information submitted on a draft environmental impact statement for the proposed adoption of Colorado river Interim Surplus Criteria (Colorado River Basin States: Interim Surplus Guidelines – Working Draft) ior Inter 17 0 f the pt. o er 29, 2 e Volume 65, No. 185, Notice of correction to n v. D Federal Register notice of availability published mb Page 57371, (Colorado River Basin States: Interim Surplus Guidelines – Working Draft) atio on Nove jo N September 22, 2000 Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 48 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 53 of 1200 ior Inter 17 the t. of r 29, 20 Dep mbe n v. tio ove jo Na ved on N va in Na 4, archi cited 1686 o. 14 N Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 54 of 1200 erior e Int 017 2 of th ept. ber 29, .D v tion ovem o Na ed on N vaj in Na 4, archiv cited 1686 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 55 of 1200 ior Inter 17 e 20 of th ept. ber 29, .D v tion ovem o Na ed on N j iv Nava d in 64, arch ite c -168 o. 14 N Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 56 of 1200 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 57 of 1200 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 58 of 1200 TABLE OF CONTENTS VOLUME I 1 INTRODUCTION AND BACKGROUND......................................................................1-1 1.1 1.1.1 1.1.2 1.1.3 1.1.4 1.1.5 INTRODUCTION ..............................................................................................1-1 Proposed Federal Action ..............................................................1-2 Background...................................................................................1-2 Purpose of and Need for Action ...................................................1-3 Relationship to the United States-Mexico Water Treaty..............1-4 Lead and Cooperating Agencies...................................................1-4 1.2 SUMMARY OF CONTENTS OF THIS FEIS...................................................1-5 1.3 WATER SUPPLY MANAGEMENT AND ALLOCATION ............................1-6 1.3.1 Colorado River System Water Supply..........................................1-6 1.3.2 Apportionment of Water Supply ..................................................1-8 1.3.2.1 The Law of the River ....................................................................1-8 1.3.2.2 Apportionment Provisions..........................................................1-10 1.3.2.2.1 Upper Division State Apportionments .......................................1-12 ior 1.3.2.2.2 Lower Division State Apportionments .......................................1-13 Inter 17 0 f the 1.3.2.2.3 Mexico Apportionment ..............................................................1-15 pt. o er 29, 2 eCriteria ..................................................1-15 1.3.3 Long-Range Operating v. D mb ation PlanNove 1.3.4 Annual Operating on ...............................................................1-16 oN avaj chive and 1.3.4.1 NNormal,rSurplusd Shortage Determinations ..........................1-16 in a 1.3.5 cited 16System Reservoirs and Diversion Facilities ...............................1-17 864, 14- Flood Control Operation.............................................................1-20 1.3.6 No. 1.3.7 Hydropower Generation .............................................................1-21 1.4 RELATED AND ONGOING ACTIONS.........................................................1-22 1.4.1 California’s Colorado River Water Use Plan .............................1-22 1.4.1.1 Imperial Irrigation District/San Diego County Water Authority Water Transfer ...........................................................1-23 1.4.1.2 All-American and Coachella Canal Lining Projects ..................1-23 1.4.2 Glen Canyon Dam Operations....................................................1-24 1.4.2.1 Adaptive Management Program.................................................1-25 1.4.2.2 Beach/Habitat-Building Flows and Beach/HabitatMaintenance Flows.....................................................................1-25 1.4.2.3 Temperature Control at Glen Canyon Dam................................1-26 1.4.3 Actions Related to the Biological and Conference Opinion on Lower Colorado River Operations and Maintenance ............1-26 1.4.4 Lower Colorado River Multi-Species Conservation Program ......................................................................................1-27 1.4.5 Secretarial Implementation Agreement Related To California’s Colorado River Water Use Plan .............................1-28 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - i Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 59 of 1200 TABLE OF CONTENTS 1.4.6 1.5 2 Offstream Storage of Colorado River Water and Development and Release of Intentionally Created Unused Apportionment In The Lower Division States ...........................1-28 DOCUMENTS INCORPORATED BY REFERENCE ...................................1-28 DESCRIPTION OF ALTERNATIVES............................................................................2-1 2.1 INTRODUCTION ..............................................................................................2-1 2.2 DEVELOPMENT OF ALTERNATIVES ..........................................................2-1 2.2.1 Operating Strategies for Surplus Determination ..........................2-1 2.2.1.1 The R Strategy..............................................................................2-1 2.2.1.2 The A Strategy..............................................................................2-1 2.2.1.3 The P Strategy ..............................................................................2-2 2.2.1.4 Flood Control Strategy .................................................................2-2 2.2.2 Origins of the California, Six States, and Basin States Alternatives ........................................................................2-2 2.2.3 Pacific Institute Proposal ..............................................................2-3 2.2.4 Formulation of Alternatives .........................................................2-4 2.2.5 Utilization of Proposals from the Basin States.............................2-5 2.2.6 No Action Alternative and Baseline Condition............................2-6 erior e Int 2.3 DESCRIPTION OF ALTERNATIVES..............................................................2-6 of th 29, 2017 pt.BaselinerCondition............................2-7 D e 2.3.1 No Action Alternative e n v. and emb 2.3.1.1 Approach atiSurplusn NovDetermination ..................................2-7 to o o Water oN avaj rchi ed 2.3.1.2 N70R BaselinevSurplus Triggers .....................................................2-8 in a 2.3.2 cited 16Basin States Alternative (Preferred alternative) .........................2-10 864, 2.3.2.1 o. 14- Approach to Surplus Water Determination ................................2-11 2.3.2.2 N Basin States Alternative Surplus Triggers..................................2-11 2.3.2.1.1 Basin States Alternative Tier 1 (70R).........................................2-14 2.3.2.1.2 Basin States Alternative Tier 2 (1145 feet msl) .........................2-14 2.3.2.1.3 Basin States Alternative Tier 3 (1125 feet msl) .........................2-14 2.3.2.2 Draft Guidelines .........................................................................2-14 2.3.3 Flood Control Alternative...........................................................2-14 2.3.3.1 Approach to Surplus Water Determination ................................2-14 2.3.3.2 Flood Control Alternative Surplus Triggers...............................2-15 2.3.4 Six States Alternative .................................................................2-15 2.3.4.1 Approach to Surplus Water Determination ................................2-15 2.3.4.2 Six States Alternative Surplus Triggers......................................2-18 2.3.4.2.1 Six States Alternative Tier 1 (70R) ............................................2-18 2.3.4.2.2 Six States Alternative Tier 2 (1145 feet msl) .............................2-19 2.3.4.2.3 Six States Alternative Tier 3.......................................................2-19 2.3.5 California Alternative .................................................................2-19 2.3.5.1 Approach to Surplus Water Determination ................................2-19 2.3.5.2 California Alternative Surplus Triggers .....................................2-19 2.3.5.2.1 California Alternative Tier 1 ......................................................2-20 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - ii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 60 of 1200 TABLE OF CONTENTS 2.3.5.2.2 2.3.5.2.3 2.3.6 2.3.6.1 2.3.6.2 2.4 3 California Alternative Tier 2 ......................................................2-20 California Alternative Tier 3 ......................................................2-20 Shortage Protection Alternative..................................................2-22 Approach to Surplus Water Determination ................................2-22 Surplus Triggers .........................................................................2-22 SUMMARY TABLE OF IMPACTS................................................................2-22 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES........3.1-1 3.1 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.1.6 INTRODUCTION ...........................................................................................3.1-1 Structure of Resource Sections..................................................3.1-1 Use of Modeling to Identify Potential Future Colorado River System Conditions ...........................................................3.1-1 Baseline Conditions...................................................................3.1-2 Impact Determination................................................................3.1-2 Period of Analysis .....................................................................3.1-2 Environmental Commitments....................................................3.1-2 3.2 POTENTIALLY AFFECTED AREA .............................................................3.2-1 3.2.1 Colorado River Segments and Issues Addressed ......................3.2-1 3.2.1.1 Lake Powell ...............................................................................3.2-3 ior Inter Lake Mead ...........3.2-3 3.2.1.2 Colorado River from Glen Canyon Dam to 017 f the pt. o er 29, 2 3.2.1.3 Lake Mead .................................................................................3.2-3 . De b 3.2.1.4 Colorado Rivern v Hoover m to the Southerly io from NoveDam at oN on International Boundary..............................................................3.2-4 avaj r NAdaptive chived in 3.2.2 a Management Program Influence on Glen cited 16Canyon Dam Releases ...............................................................3.2-5 864, 4- o. 1 N 3.3 RIVER SYSTEM OPERATIONS ...................................................................3.3-1 3.3.1 Operation of the Colorado River System ..................................3.3-1 3.3.1.1 Operation of Glen Canyon Dam................................................3.3-2 3.3.1.2 Operation of Hoover Dam .........................................................3.3-3 3.3.2 Natural Runoff and Storage of Water........................................3.3-6 3.3.3 Modeling and Future Hydrology ...............................................3.3-9 3.3.3.1 Model Configuration .................................................................3.3-9 3.3.3.2 Interim Surplus Criteria Modeled..............................................3.3-9 3.3.3.3 General Modeling Assumptions ..............................................3.3-10 3.3.3.4 Lake Mead Water Level Protection Assumptions...................3.3-12 3.3.3.5 Computational Procedures.......................................................3.3-13 3.3.3.6 Post-Processing and Data Interpretation Procedures...............3.3-14 3.3.4 Modeling Results.....................................................................3.3-15 3.3.4.1 General Observations Concerning Modeling Results .............3.3-15 3.3.4.2 Lake Powell Water Levels.......................................................3.3-18 3.3.4.2.1 Dam and Reservoir Configuration...........................................3.3-18 3.3.4.2.2 Historic Water Levels..............................................................3.3-19 3.3.4.2.3 Baseline Conditions.................................................................3.3-19 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - iii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 61 of 1200 TABLE OF CONTENTS 3.3.4.2.4 3.3.4.3 3.3.4.4 3.3.4.4.1 3.3.4.4.2 3.3.4.4.3 3.3.4.4.4 3.3.4.5 3.3.4.5.1 3.3.4.5.2 3.3.4.5.3 3.3.4.5.4 Comparison of Surplus Alternatives to Baseline Conditions.................................................................3.3-25 River Flows Between Lake Powell and Lake Mead................3.3-27 Lake Mead Water Levels.........................................................3.3-29 Dam and Reservoir Configuration...........................................3.3-29 Historic Lake Mead Water Levels...........................................3.3-31 Baseline Conditions.................................................................3.3-31 Comparison of Surplus Alternatives to Baseline Conditions.................................................................3.3-37 Comparison of River Flows Below Hoover Dam ...................3.3-42 River Flows Between Hoover Dam and Parker Dam..............3.3-45 River Flows Between Parker Dam and Palo Verde Diversion .................................................................................3.3-54 River Flows Between Palo Verde Diversion Dam and Imperial Dam...........................................................................3.3-63 River Flows Between Imperial Dam and Morelos Dam .........3.3-71 3.4 WATER SUPPLY............................................................................................3.4-1 3.4.1 Introduction ...............................................................................3.4-1 3.4.2 Methodology..............................................................................3.4-1 ior 3.4.3 Affected Environment ...............................................................3.4-1 Inter 17 0 f the 3.4.3.1 Water Use Projection Process....................................................3.4-3 pt. o er 29, 2 e v. D 3.4.3.2 State of Arizona.........................................................................3.4-3 mb ation on Nove 3.4.3.3 Statejo N of California......................................................................3.4-7 ava Nevada........................................................................3.4-12 NState of rchived 3.4.3.4 d in 64, a 3.4.3.5 cite 8 16Upper Basin States ..................................................................3.4-14 . 14- Mexico.....................................................................................3.4-14 3.4.3.6 No 3.4.4 Environmental Consequences..................................................3.4-16 3.4.4.1 State of Arizona.......................................................................3.4-17 3.4.4.1.1 Baseline Conditions.................................................................3.4-17 3.4.4.1.2 Comparison of Surplus Alternatives to Baseline Conditions.................................................................3.4-23 3.4.4.2 State of California....................................................................3.4-26 3.4.4.2.1 Baseline Conditions.................................................................3.4-26 3.4.4.2.2 Comparison of Surplus Alternatives to Baseline Conditions.................................................................3.4-31 3.4.4.3 State of Nevada........................................................................3.4-34 3.4.4.3.1 Baseline Conditions.................................................................3.4-34 3.4.4.3.2 Comparison of Surplus Alternatives to Baseline Conditions.................................................................3.4-38 3.4.4.4 Upper Basin States ..................................................................3.4-41 3.4.4.5 Mexico.....................................................................................3.4-42 3.4.4.5.1 Baseline Conditions.................................................................3.4-42 3.4.4.5.2 Comparison of Surplus Alternatives to Baseline Conditions.................................................................3.4-47 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - iv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 62 of 1200 TABLE OF CONTENTS 3.5 WATER QUALITY.........................................................................................3.5-1 3.5.1 Introduction ...............................................................................3.5-1 3.5.2 Colorado River Salinity.............................................................3.5-1 3.5.2.1 Methodology..............................................................................3.5-1 3.5.2.2 Affected Environment ...............................................................3.5-2 3.5.2.2.1 Historical Data...........................................................................3.5-2 3.5.2.2.2 Regulatory Requirements and Salinity Control Programs ........3.5-3 3.5.2.2.3 General Municipal, Industrial, and Agricultural Effects of Increased Salinity Concentrations .............................................3.5-6 3.5.2.3 Environmental Consequences....................................................3.5-9 3.5.3 Lake Mead Water Quality and Las Vegas Water Supply..........3.5-9 3.5.3.1 Methodology..............................................................................3.5-9 3.5.3.2 Affected Environment .............................................................3.5-11 3.5.3.2.1 General Description.................................................................3.5-11 3.5.3.2.2 Lake Mead Water Quality and Limnology..............................3.5-16 3.5.3.2.3 Hydrodynamics of Lake Mead and Boulder Basin .................3.5-19 3.5.3.3 Environmental Consequences..................................................3.5-20 3.5.3.3.1 General Effects of Reduced Lake Levels ................................3.5-20 3.5.3.3.1.1 Volume Reduction...................................................................3.5-22 ior 3.5.3.3.1.2 Tributary Water Quality ..........................................................3.5-22 Inter 17 3.5.3.3.2 Comparison of Baseline Conditions and , 20 Alternatives.............3.5-22 f the pt. o er 29 e 3.5.3.3.2.1 Baseline Conditions.................................................................3.5-23 v. D mb 3.5.3.3.2.2 Basin StatestiAlternative ..........................................................3.5-23 a on on Nove oN 3.5.3.3.2.3 avaj chived NBaselinerConditions.................................................................3.5-25 a 3.5.3.3.2.4 in Basin States Alternative ..........................................................3.5-25 cited 16864, 3.5.3.3.2.5 4- Flood Control Alternative........................................................3.5-25 1 No. 3.5.3.3.2.6 Six States Alternative ..............................................................3.5-25 3.5.3.3.2.7 California Alternative ..............................................................3.5-25 3.5.3.3.2.8 Shortage Protection Alternative...............................................3.5-26 3.5.3.3.2.9 Summary of Changes in Lake Mead Volume and Elevation..................................................................................3.5-26 3.5.4 Water Quality Between Hoover Dam and Southerly International Boundary............................................................3.5-26 3.6 RIVERFLOW ISSUES ....................................................................................3.6-1 3.6.1 Introduction ...............................................................................3.6-1 3.6.2 Beach/Habitat-Building Flows ..................................................3.6-1 3.6.2.1 Methodology..............................................................................3.6-2 3.6.2.2 Affected Environment ...............................................................3.6-2 3.6.2.3 Environmental Consequences....................................................3.6-3 3.6.2.3.1 Baseline Conditions...................................................................3.6-5 3.6.2.3.2 Basin States Alternative ............................................................3.6-5 3.6.2.3.3 Flood Control Alternative..........................................................3.6-5 3.6.2.3.4 Six States Alternative ................................................................3.6-5 3.6.2.3.5 California Alternative ................................................................3.6-5 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - v Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 63 of 1200 TABLE OF CONTENTS 3.6.2.3.6 3.6.3 3.6.3.1 3.6.3.2 3.6.4 3.6.4.1 3.6.4.1.1 3.6.4.1.2 3.6.4.1.3 3.6.4.1.4 3.6.4.1.5 3.6.4.1.6 3.6.4.2 Shortage Protection Alternative.................................................3.6-6 Low Steady Summer Flow ........................................................3.6-6 Affected Environment ...............................................................3.6-6 Environmental Consequences....................................................3.6-6 Flooding Downstream of Hoover Dam .....................................3.6-8 Affected Environment ...............................................................3.6-9 Hoover Dam to Davis Dam .......................................................3.6-9 Davis Dam to Parker Dam.........................................................3.6-9 Hoover Dam to Davis Dam .....................................................3.6-10 Davis Dam to Parker Dam.......................................................3.6-10 Parker Dam to Laguna Dam ....................................................3.6-10 Laguna Dam to SIB .................................................................3.6-10 Environmental Consequences..................................................3.6-11 3.7 AQUATIC RESOURCES................................................................................3.7-1 3.7.1 Introduction ...............................................................................3.7-1 3.7.2 Lake Habitat ..............................................................................3.7-1 3.7.2.1 Methodology..............................................................................3.7-1 3.7.2.2 Affected Environment ...............................................................3.7-2 3.7.2.2.1 Lake Powell ...............................................................................3.7-2 ior 3.7.2.2.2 Lake Mead .................................................................................3.7-4 Inter 17 the ....................................3.7-4 0 3.7.2.2.3 General Effects of Reservoirof pt. Operation9, 2 e r2 3.7.2.3. Environmental n v. D Consequences....................................................3.7-5 mbe atio ...........................................................................3.7-5 Nove 3.7.3 Sportjo N Fisheries n ava rchived o NMethodology..............................................................................3.7-6 3.7.3.1 d in 64, a 3.7.3.2 cite 8 16Affected Environment ...............................................................3.7-6 . 14- Reservoir Sport Fisheries ..........................................................3.7-7 3.7.3.2.1 No 3.7.3.3 Environmental Consequences....................................................3.7-7 3.7.3.3.1 Reservoir Sport Fisheries ..........................................................3.7-7 3.7.3.3.2 Colorado River Sport Fisheries .................................................3.7-8 3.8 SPECIAL-STATUS SPECIES ........................................................................3.8-1 3.8.1 Introduction ...............................................................................3.8-1 3.8.2 Methodology..............................................................................3.8-2 3.8.3 Affected Environment ...............................................................3.8-2 3.8.3.1 Lake and Riparian Habitat.........................................................3.8-2 3.8.3.1.1 Lakeside Habitat ........................................................................3.8-2 3.8.3.1.2 Riverside Habitat .......................................................................3.8-5 3.8.3.2 Special-Status Plant Species......................................................3.8-6 3.8.3.2.1 Plant Species Removed from Further Consideration ................3.8-8 3.8.3.2.2 Plant Species Considered Further..............................................3.8-8 3.8.3.3 Special-Status Wildlife Species...............................................3.8-10 3.8.3.3.1 Wildlife Species Removed from Further Consideration .........3.8-12 3.8.3.3.2 Special-Status Wildlife Species Considered Further...............3.8-14 3.8.3.4 Special-Status Fish Species .....................................................3.8-18 3.8.4 Environmental Consequences..................................................3.8-22 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - vi Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 64 of 1200 TABLE OF CONTENTS 3.8.4.1 3.8.4.1.1 3.8.4.1.2 3.8.4.2 3.8.4.2.1 3.8.4.2.2 3.8.4.3 3.8.4.3.1 3.8.4.3.2 Effects on Special-Status Plant Species ..................................3.8-22 Baseline Conditions.................................................................3.8-22 Effects of the Alternatives .......................................................3.8-23 Effects on Special-Status Wildlife Species .............................3.8-24 Baseline Conditions.................................................................3.8-24 Effects of the Alternatives .......................................................3.8-25 Effects on Special-Status Fish Species....................................3.8-25 Baseline Conditions.................................................................3.8-26 Effects of the Alternatives .......................................................3.8-27 3.9 3.9.1 3.9.2 RECREATION ................................................................................................3.9-1 Introduction ...............................................................................3.9-1 Reservoir Marinas, Boat Launching and Shoreline Access .......................................................................3.9-1 3.9.2.1 Methodology..............................................................................3.9-1 3.9.2.2 Affected Environment ...............................................................3.9-2 3.9.2.2.1 Lake Powell Recreation Resources ...........................................3.9-2 3.9.2.2.2 Shoreline Public Use Facilities..................................................3.9-5 3.9.2.2.2.1 Threshold Elevations .................................................................3.9-8 3.9.2.2.3 Lake Mead Recreation Resources .............................................3.9-9 ior 3.9.2.2.4 Shoreline Public Use Facilities at Lake tMead...........................3.9-9 In er 17 0 f the 3.9.2.2.4.1 Threshold Elevations ...............................................................3.9-13 pt. o er 29, 2 e 3.9.2.3 Environmental n v. D mb o Consequences..................................................3.9-13 ati.............................................................................3.9-14 Nove 3.9.2.3.1 Lakejo N Powell n ava chived o NBaselinerConditions.................................................................3.9-20 3.9.2.3.1.1 in a cited 3.9.2.3.1.2 16Basin States Alternative ..........................................................3.9-20 864, 1 - Flood Control Alternative........................................................3.9-21 3.9.2.3.1.3 4 No. 3.9.2.3.1.4 Six States Alternative ..............................................................3.9-21 3.9.2.3.1.5 California Alternative ..............................................................3.9-21 3.9.2.3.1.6 Shortage Protection Alternative...............................................3.9-22 3.9.2.3.2 Lake Mead ...............................................................................3.9-22 3.9.2.3.2.1 Baseline Conditions.................................................................3.9-25 3.9.2.3.2.2 Basin States Alternative ..........................................................3.9-25 3.9.2.3.2.3 Flood Control Alternative........................................................3.9-25 3.9.2.3.2.4 Six States Alternative ..............................................................3.9-25 3.9.2.3.2.5 California Alternative ..............................................................3.9-25 3.9.2.3.2.6 Shortage Protection Alternative...............................................3.9-26 3.9.3 Reservoir Boating/Navigation .................................................3.9-26 3.9.3.1 Methodology............................................................................3.9-26 3.9.3.2 Affected Environment .............................................................3.9-27 3.9.3.2.1 Lake Powell Boating Navigation and Safety...........................3.9-27 3.9.3.2.1.1 Lake Powell Safe Boating Capacity ........................................3.9-28 3.9.3.2.2 Lake Mead Boating Navigation and Safety.............................3.9-29 3.9.3.2.3 Lake Mead Safe Boating Capacity ..........................................3.9-30 3.9.3.3 Environmental Consequences..................................................3.9-31 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - vii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 65 of 1200 TABLE OF CONTENTS 3.9.3.3.1 3.9.3.3.1.1 3.9.3.3.1.2 3.9.3.3.1.3 3.9.3.3.1.4 3.9.3.3.1.5 3.9.3.3.1.6 3.9.3.3.2 3.9.3.3.2.1 3.9.3.3.2.2 3.9.3.3.2.3 3.9.3.3.2.4 3.9.3.3.2.5 3.9.3.3.2.6 3.9.4 3.9.5 3.9.5.1 3.9.5.2 3.9.5.2.1 3.9.5.2.2 3.9.5.2.3 3.9.5.3 3.9.5.3.1 Lake Powell .............................................................................3.9-32 Baseline Conditions.................................................................3.9-34 Basin States Alternative ..........................................................3.9-34 Flood Control Alternative........................................................3.9-34 Six States Alternative ..............................................................3.9-35 California Alternative ..............................................................3.9-35 Shortage Protection Alternative...............................................3.9-35 Lake Mead ...............................................................................3.9-35 Baseline Conditions.................................................................3.9-37 Basin States Alternative ..........................................................3.9-37 Flood Control Alternative........................................................3.9-38 Six States Alternative ..............................................................3.9-38 California Alternative ..............................................................3.9-38 Shortage Protection Alternative...............................................3.9-38 River and Whitewater Boating ................................................3.9-39 Sport Fishing ...........................................................................3.9-39 Methodology............................................................................3.9-40 Affected Environment .............................................................3.9-40 Sport Fishing in Lake Powell ..................................................3.9-40 ior Sport Fishing in Lake Mead ....................................................3.9-41 Inter 17 the Sport Fishing in Lake Mohavef................................................3.9-43 0 pt. o er 29, 2 e Environmental Consequences..................................................3.9-44 v. D mb Sport Fishingon Lake Powell, Lake Mead and ati in on Nove oN avaj rchived NLake Mohave ...........................................................................3.9-44 in a 3.9.6 cited 16Recreational Facilities Operational Costs ...............................3.9-45 864, 3.9.6.1 14- Methodology............................................................................3.9-45 No. 3.9.6.2 Affected Environment .............................................................3.9-45 3.9.6.2.1 Lake Powell .............................................................................3.9-45 3.9.6.2.2 Lake Mead ...............................................................................3.9-47 3.9.6.3 Environmental Consequences..................................................3.9-48 3.9.6.3.1 Lake Powell .............................................................................3.9-48 3.9.6.3.2 Lake Mead ...............................................................................3.9-48 3.10 ENERGY RESOURCES ...............................................................................3.10-1 3.10.1 Introduction .............................................................................3.10-1 3.10.2 Hydropower .............................................................................3.10-1 3.10.2.1 Methodology............................................................................3.10-1 3.10.2.2 Affected Environment .............................................................3.10-2 3.10.2.2.1 Factors of Power Production ...................................................3.10-2 3.10.2.2.2 Power Marketing and Customers ............................................3.10-3 3.10.2.3 Environmental Consequences..................................................3.10-4 3.10.2.3.1 Baseline Conditions.................................................................3.10-5 3.10.2.3.1.1 Glen Canyon Dam ...................................................................3.10-5 3.10.2.3.1.2 Hoover Dam ............................................................................3.10-5 3.10.2.3.1.3 Combined Capacity and Energy Reduction Under COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - viii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 66 of 1200 TABLE OF CONTENTS Baseline Conditions.................................................................3.10-8 Basin States Alternative ..........................................................3.10-8 Glen Canyon Dam ...................................................................3.10-8 Hoover Dam ............................................................................3.10-8 Flood Control Alternative........................................................3.10-8 Glen Canyon Dam ...................................................................3.10-8 Hoover Dam ............................................................................3.10-9 Six States Alternative ..............................................................3.10-9 Glen Canyon Dam ...................................................................3.10-9 Hoover Dam ............................................................................3.10-9 California Alternative ............................................................3.10-10 Glen Canyon Dam .................................................................3.10-10 Hoover Dam ..........................................................................3.10-10 Shortage Protection Alternative.............................................3.10-10 Glen Canyon Dam .................................................................3.10-10 Hoover Dam ..........................................................................3.10-11 Comparison of Alternatives...................................................3.10-11 Southern Nevada Water System Lake Mead Intake Energy Requirements ............................................................3.10-13 ior 3.10.3.1 Methodology..........................................................................3.10-13 Inter 17 3.10.3.2 Affected Environment ...........................................................3.10-13 0 f the pt. o er 29, 2 e 3.10.3.3 Environmental Consequences................................................3.10-13 v. D mb 3.10.3.3.1 Baseline Conditions and ove ation on N Alternatives....................................3.10-14 oN 3.10.4 avaj Energy Requirements at Lake Powell ........................3.10-14 NIntake archived 3.10.4.1 cited in Methodology..........................................................................3.10-14 864, 16Affected Environment ...........................................................3.10-15 3.10.4.2 . 14o 3.10.4.3N Environmental Consequences................................................3.10-15 3.10.2.3.2 3.10.2.3.2.1 3.10.2.3.2.2 3.10.2.3.3 3.10.2.3.3.1 3.10.2.3.3.2 3.10.2.3.4 3.10.2.3.4.1 3.10.2.3.4.2 3.10.2.3.5 3.10.2.3.5.1 3.10.2.3.5.2 3.10.2.3.6 3.10.2.3.6.1 3.10.2.3.6.2 3.10.2.4 3.10.3 3.11 AIR QUALITY ..............................................................................................3.11-1 3.11.1 Introduction .............................................................................3.11-1 3.11.2 Fugitive Dust from Exposed Shoreline ...................................3.11-1 3.11.2.1 Methodology............................................................................3.11-1 3.11.2.2 Affected Environment .............................................................3.11-2 3.11.2.3 Environmental Consequences..................................................3.11-3 3.12 VISUAL RESOURCES.................................................................................3.12-1 3.12.1 Introduction .............................................................................3.12-1 3.12.2 Methodology............................................................................3.12-1 3.12.3 Affected Environment .............................................................3.12-1 3.12.3.1 Lake Powell .............................................................................3.12-2 3.12.3.1.1 Landscape Character................................................................3.12-2 3.12.3.1.2 Sensitive Viewing Locations ...................................................3.12-2 3.12.3.2 Lake Mead ...............................................................................3.12-3 3.12.3.2.1 Landscape Character................................................................3.12-3 3.12.3.2.2 Sensitive Viewing Locations ...................................................3.12-3 3.12.4 Environmental Consequences..................................................3.12-4 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - ix Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 67 of 1200 TABLE OF CONTENTS 3.12.4.1 3.12.4.1.1 3.12.4.1.2 3.12.4.2 3.12.4.2.1 3.12.4.2.2 3.12.4.3 3.12.4.3.1 3.12.4.3.2 3.12.4.4 3.12.4.4.1 3.12.4.4.2 3.12.4.5 3.12.4.5.1 3.12.4.5.2 3.12.4.6 3.12.4.6.1 3.12.4.6.2 3.13 3.13.1 3.13.2 3.13.3 3.13.4 Baseline Conditions.................................................................3.12-4 Lake Powell .............................................................................3.12-4 Lake Mead ...............................................................................3.12-5 Basin States Alternative ..........................................................3.12-6 Lake Powell .............................................................................3.12-6 Lake Mead ...............................................................................3.12-6 Flood Control Alternative........................................................3.12-6 Lake Powell .............................................................................3.12-6 Lake Mead ...............................................................................3.12-6 Six States Alternative ..............................................................3.12-7 Lake Powell .............................................................................3.12-7 Lake Mead ...............................................................................3.12-7 California Alternative ..............................................................3.12-7 Lake Powell .............................................................................3.12-7 Lake Mead ...............................................................................3.12-8 Shortage Protection Alternative...............................................3.12-8 Lake Powell .............................................................................3.12-8 Lake Mead ...............................................................................3.12-8 CULTURAL RESOURCES ..........................................................................3.13-1 ior Introduction .............................................................................3.13-1 Inter 17 0 f the Approach to Analysis ..............................................................3.13-1 pt. o er 29, 2 e v. D Affected Environment .............................................................3.13-2 mb ation on Nove Environmental Consequences..................................................3.13-3 ajo N d Nav hive n 3.14 INDIAN iTRUST4, arc ............................................................................3.14-1 ASSETS cited 16Introduction .............................................................................3.14-1 86 3.14.1 14No. 3.14.2 Ten Tribes Partnership ............................................................3.14-1 3.14.2.1 Northern Ute Indian Tribe – Uintah and Ouray Reservation ..............................................................................3.14-2 3.14.2.2 Jicarilla Apache Indian Reservation ........................................3.14-3 3.14.2.3 Navajo Indian Reservation ......................................................3.14-4 3.14.2.4 Southern Ute Reservation........................................................3.14-5 3.14.2.5 Ute Mountain Ute Indian Reservation.....................................3.14-5 3.14.2.6 Fort Mojave Indian Reservation ..............................................3.14-6 3.14.2.7 Chemehuevi Indian Reservation..............................................3.14-7 3.14.2.8 Colorado River Indian Reservation .........................................3.14-7 3.14.2.9 Quechan Indian Reservation (Fort Yuma)...............................3.14-8 3.14.2.10 Cocopah Indian Tribe ..............................................................3.14-9 3.14.2.11 Environmental Consequences................................................3.14-10 3.14.2.11.1 Upper Basin Mainstem Tribes...............................................3.14-10 3.14.2.11.2 Lower Basin Mainstem Tribes ..............................................3.14-11 3.14.3 Tribes served by Central Arizona Project..............................3.14-11 3.14.3.1 Water Rights Setting..............................................................3.14-11 3.14.3.1.1 CAP Priority Scheme ............................................................3.14-11 3.14.3.1.2 Examples of Reductions of CAP Water Deliveries...............3.14-14 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - x Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 68 of 1200 TABLE OF CONTENTS 3.14.3.2 3.14.3.2.1 3.14.3.2.2 3.15 Environmental Consequences................................................3.14-18 Impacts Resulting from Baseline Conditions and Alternatives.....................................................................3.14-18 Summary of Impacts..............................................................3.14-20 ENVIRONMENTAL JUSTICE ....................................................................3.15-1 3.16 TRANSBOUNDARY IMPACTS..................................................................3.16-1 3.16.1 Introduction .............................................................................3.16-1 3.16.2 Methodology............................................................................3.16-1 3.16.3 Consultation With Mexico ......................................................3.16-2 3.16.4 Affected Environment .............................................................3.16-4 3.16.4.1 Historical Colorado River Between the Southerly International Boundary and the Gulf of California .................3.16-4 3.16.4.2 Present Status of the Colorado River Between the NIB and the Gulf of California........................................................3.16-5 3.16.5 Excess Flows to Mexico........................................................3.16-10 3.16.5.1 Baseline Conditions...............................................................3.16-10 3.16.5.2 Comparison of Surplus Alternatives to Baseline Conditions...............................................................3.16-15 3.16.5.3 Potential Transboundary Effects of Reduced r terio Flood Flow Frequency .....................................................................3.16-22 he In 2017 of t 9, 3.16.5.3.1 General Effects of . Dept. Flood Flows.............................................3.16-22 ber 2 v 3.16.5.3.2 Effects of ation Excessvem N Reducedon No Flows..........................................3.16-23 o 3.16.5.4 Summary Ofved avaj i Potential Effects To Special-Status Status in Nand4, archIn Mexico ...........................................................3.16-23 Habitat d cite 16Potential Effects to Habitat in Mexico ..................................3.16-23 86 3.16.5.5 . 14- Potential Effects to Special Status-Species in Mexico .........3.16-24 No 3.16.5.5.1 3.16.5.5.2 Desert pupfish........................................................................3.16-24 3.16.5.5.3 Vaquita ..................................................................................3.16-26 3.16.5.5.4 Totoaba ..................................................................................3.16-28 3.16.5.5.5 Southwestern Willow Flycatcher...........................................3.16-30 3.16.5.5.6 Yuma Clapper Rail ................................................................3.16-33 3.16.5.5.7 Yellow-billed Cuckoo ...........................................................3.16-36 3.16.5.5.8 California Black Rail .............................................................3.16-37 3.16.5.5.9 Elf Owl ..................................................................................3.16-38 3.16.5.5.10 Bell’s Vireo ...........................................................................3.16-39 3.16.5.5.11 Clark’s Grebe.........................................................................3.16-40 3.17 3.17.1 3.17.2 3.17.3 3.17.4 3.17.5 3.17.6 SUMMARY OF ENVIRONMENTAL COMMITMENTS ..........................3.17-1 Water Quality ..........................................................................3.17-1 Riverflow Issues ......................................................................3.17-2 Aquatic Resources ...................................................................3.17-2 Special-Status Species .............................................................3.17-2 Recreation................................................................................3.17-2 Cultural Resources...................................................................3.17-2 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xi Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 69 of 1200 TABLE OF CONTENTS 3.17.7 4 Transboundary Impacts ...........................................................3.17-3 OTHER NEPA CONSIDERATIONS...............................................................................4-1 4.1 4.2 CUMULATIVE IMPACTS................................................................................4-1 4.3 RELATIONSHIP BETWEEN SHORT-TERM USES OF THE ENVIRONMENT AND LONG-TERM PRODUCTIVITY...............................4-2 4.4 5 INTRODUCTION ..............................................................................................4-1 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES .....................................................................................................4-3 CONSULTATION AND COORDINATION...................................................................5-1 5.1 INTRODUCTION ..............................................................................................5-1 5.2 5.2.1 5.2.2 GENERAL PUBLIC INVOLVEMENT ACTIVITIES......................................5-1 Project Scoping.............................................................................5-1 Public Review Of DEIS................................................................5-2 5.3 5.3.1 5.3.2 FEDERAL AGENCY COORDINATION .........................................................5-2 National Park Service ...................................................................5-2 United States Section of the International rior te Boundary and he In 2017 Water Commission .......................................................................5-3 . of t r 2 ........................................5-3 e Indian Affairs 9, United States Bureau of pt be v. D United Stateson and NovemService Including ati Fish on Wildlife oN avaj rch ved NEndangered iSpecies Act Compliance...........................................5-3 in a cited 16National Marine Fisheries Service ...............................................5-4 864, Historic Preservation Act Compliance ..........................5-5 14- National 5.3.3 5.3.4 5.3.5 5.3.6 No. 5.4 TRIBAL CONSULTATION ..............................................................................5-6 5.5 STATE AND LOCAL WATER AND POWER AGENCIES COORDINATION ..............................................................................................5-6 5.6 NON-GOVERNMENTAL ORGANIZATIONS COORDINATION ................5-7 5.7 MEXICO CONSULTATION .............................................................................5-7 5.8 SUMMARY OF COORDINATION CONTACTS ............................................5-8 5.9 FEDERAL REGISTER NOTICES...................................................................5-12 Glossary GL-1 Index IND-1 References Cited REF-1 List of Preparers LOP-1 Document Distribution DIST-1 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 70 of 1200 TABLE OF CONTENTS List of Tables Table 1-1 Documents Included in the Law of the River............................................1-11 Table 1-2 Colorado River Storage Facilities and Major Diversion Dams from Lake Powell to Morelos Dam....................................................................1-19 Table 2-1 Baseline Potential Surplus Water Supply..................................................2-10 Table 2-2 Basin States Alternative Potential Surplus Water Supply.........................2-13 Table 2-3 Flood Control Potential Alternative Surplus Water Supply ......................2-15 Table 2-4 Six States Alternative Potential Surplus Water Supply.............................2-18 Table 2-5 California Alternative Potential Surplus Water Supply ............................2-20 Table 2-6 Shortage Protection Alternative Potential Surplus Water Supply.............2-22 Table 2-7 Summary of Potential Effects of Implementing Interim Surplus Criteria.......................................................................................................2-24 Table 3.3-1 Glen Canyon Dam Release Restrictions...................................................3.3-3 Table 3.3-2 Minimum Required Colorado River System Storage or Space ....................3.3-4 Table 3.3-3 Table 3.3-4 Table 3.3-5 teri ,2 er 29 In Minimum Flood Control Releases at Hoover Dam ..................................3.3-5 017 f the pt. o Lake Powell End-of-July Water e emb Comparison of Surplus v. D Elevations; ation Condition; 90th, 50th and 10th Alternatives and Baseline on Nov ajo N Percentileav ....................................................................................3.3-25 N Valuesrchived in a ed citLake Powell 4, 1686 End-of-July Water Elevations; Comparison of Surplus . 14NoAlternatives and Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 3695 Feet ........................................3.3-27 Table 3.3-6 Lake Powell End-of-July Water Elevations; Comparison of Surplus Alternatives and Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 3612 Feet ........................................3.3-27 Table 3.3-7 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions; 90th, 50th and 10th Percentile Values .............................................................................3.3-37 Table 3.3-8 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives and Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1200 Feet ............................3.3-41 Table 3.3-9 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1083 Feet ............................3.3-41 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xiii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 71 of 1200 TABLE OF CONTENTS Table 3.3-10 Table 3.3-11 Lake Mead End-of-December Water Elevations;Comparison of Surplus Alternatives and Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1050 Feet ............................3.3-41 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives and Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1000 Feet ............................3.3-42 Table 3.3-12 Colorado River Flow Locations Identified for Evaluation ....................3.3-42 Table 3.3-13 Comparison of Mean Monthly Flow (cfs) – Baseline Conditions and Surplus Alternatives; Colorado River Downstream of Havasu NWR (River Mile = 242.3); 70th Percentile Values for Year 2016........3.3-48 Table 3.3-14 Comparison of Mean Monthly Flow (cfs) – Baseline Conditions and Surplus Alternatives; Colorado River Upstream of CRIR Diversion (River Mile = 180.8); 70th Percentile Values for Year 2016 ..................3.3-58 Table 3.3-15 Comparison of Mean Monthly Flow (cfs) – Baseline Conditions and Surplus Alternatives; Colorado River Downstream of Palo Verde Diversion Dam (River Mile = 133.8); 70th Percentile Values for ior Year 2016 ...............................................................................................3.3-64 Inter Table 3.3-16 Table 3.4-1 f the 017 9, 2 Comparison of Mean Monthly Flow.Data – Baseline Conditions pt o . De Riverber 2 and Surplus Alternatives; Colorado vem Downstream of Morelos nv o Natio d onPercentile Values (cfs) Dam (River Mile = 23.1); 90th N vajo hive Na for Year 2016..........................................................................................3.3-75 d in , arc cite 16864 Summary of Arizona Modeled Annual Depletions; Comparison . 14Noof Surplus Alternatives to Baseline Conditions......................................3.4-24 Table 3.4-2 Summary of California Modeled Annual Depletions; Comparison of Surplus Alternatives to Baseline Conditions......................................3.4-33 Table 3.4-3 Summary of Nevada Modeled Annual Depletions; Comparison of Surplus Alternatives to Baseline Conditions......................................3.4-41 Table 3.4-4 Summary of Mexico Modeled Annual Depletions; Comparison of Surplus Alternatives to Baseline Conditions......................................3.4-47 Table 3.5-1 Estimated Colorado River Salinity in 2016............................................3.5-10 Table 3.5-2 Estimated Colorado River Salinity in 2050............................................3.5-10 Table 3.5-3 Morphometric Characteristics of Lake Mead.........................................3.5-12 Table 3.5-4 Chemical Characteristics of Colorado River ..........................................3.5-16 Table 3.5-5 Hydraulic Inputs for Lake Mead ............................................................3.5-18 Table 3.5-6 Modeled Characteristics of Lake Mead Under Baseline and Alternative Conditions............................................................................3.5-24 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xiv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 72 of 1200 TABLE OF CONTENTS Table 3.5-7 Modeled Comparisons of Alternatives to Baseline Conditions .............3.5-24 Table 3.6-1 Probabilities of BHBF Releases from Glen Canyon Dam .......................3.6-3 Table 3.6-2 Probability of Minimum Glen Canyon Dam Releases (Annual Releases of 8.23 maf) .................................................................3.6-8 Table 3.6-3 Development in Flood Plains Between Hoover Dam and SIB, 1979 Data .......................................................................................3.6-10 Table 3.6-4 Discharge Probabilities from Hoover, Davis and Parker Dams .............3.6-12 Table 3.6-5 Estimated Flood Damages Between Hoover Dam and the SIB (1979 level of development and 2000 price level1)................................3.6-12 Table 3.7-1 Fish Species Present in the Project Area ..................................................3.7-3 Table 3.8-1 Special-Status Plant Species Potentially Occurring Within the Area of Analysis .......................................................................................3.8-7 Table 3.8-2 Special-Status Wildlife Species Potentially Occurring Within the Area of Analysis .....................................................................................3.8-11 Table 3.8-3 Special-Status Fish Species Potentially Occurring Within the r Area of Analysis .....................................................................................3.8-18 terio Table 3.9-1 Table 3.9-2 he In r mbe 7 01 Glen Canyon National Recreationpt. ofVisitation,..................................3.9-3 Area t 29 2 . De n ed o Lake Powell Shorelineon v Useove ati Public N Facilities............................................3.9-6 jo N ited 6864, a Table 3.9-4 c Probabilities of Lake Powell Elevation Exceeding 3677 feet -1 . July oin14 .....................................................................................................3.9-17 N Table 3.9-3 Laken Nava rcPublic Use Facilities ...............................................3.9-10 i Mead Marina hiv Table 3.9-5 Probabilities of Lake Powell Elevation Exceeding 3612 feet in July .....................................................................................................3.9-18 Table 3.9-6 Comparison of Lake Mead Elevation Exceedance Probabilities for Elevation 1183 Feet ..........................................................................3.9-22 Table 3.9-7 Lake Powell Safe Boating Capacity at Water Surface Elevations .........3.9-29 Table 3.9-8 Lake Mead Safe Boating Capacity at Water Surface Elevations ...........3.9-31 Table 3.9-9 Probabilities of Lake Powell Elevation Exceeding 3626 feet in July .....................................................................................................3.9-34 Table 3.9-10 Probabilities of Lake Mead End-of-December Elevation Exceeding 1170 feet .................................................................................................3.9-37 Table 3.9-11 Nevada Division of Wildlife Annual Angler Questionnaire Results for Lake Mead............................................................................3.9-42 Table 3.9-12 Lake Mohave Developed Recreation Facilities......................................3.9-43 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 73 of 1200 TABLE OF CONTENTS Table 3.9-13 Costs Associated with Adjustments to Lake Powell Recreation Facilities .................................................................................................3.9-46 Table 3.9-14 Costs Incurred to Recreational Facilities from Lake Mead Pool Fluctuations (Year 2000 Price Level).....................................................3.9-47 Costs Associated with Potential Relocation of Lake Powell Recreational Facilities Under Alternatives; Compared to Baseline Conditions (Year 2000 Price Level).......................................................3.9-48 Table 3.9-15 Table 3.9-16 Costs Associated with Potential Relocation of Lake Mead Recreational Facilities Under Alternatives Compared to Baseline Conditions................................................................................3.9-49 Table 3.10-1 Hydropower Capacity and Energy – Comparison of Alternatives to Baseline Conditions; (Difference between baseline conditions and each alternative2) ..........................................................................3.10-12 Table 3.10-2 Southern Nevada Water System Lake Mead Intake Energy Requirements Average Annual Power Cost – Comparison of Alternatives to Baseline Conditions; (Differences between baseline conditions and each alternative) ...........................................................3.10-14 Table 3.10-3 r io Intake Energy Requirements at Lake Powell Average Annual Inter 17 heBaseline0Conditions Power Cost – Comparison of Alternatives to of t 9 2 ept. and reach ,alternative) ...........3.10-16 (Difference between baseline D . conditions be 2 v m n e Natio d on Nov Table 3.11-1 Median Lake Mead Surface Elevation ajo av ive SurfaceN d in Area4and rch , a Exposed Shoreline Area Under Baseline e citConditions6 Alternative Projections..................................................3.11-5 168 and . 14o Table 3.11-2 N Median Lake Powell Surface Elevation, Surface Area and Exposed Shoreline Area Under Baseline Conditions and Alternative Projections ..............................................................................................3.11-6 Table 3.14-1 Central Arizona Project Indian Water Allocations...............................3.14-13 Table 3.14-2 Traditional Reclamation Priorities for Central Arizona Project Water ........................................................................................3.14-15 Table 3.14-3 Reductions in Indian CAP Water Supplies During Times of Shortage on Colorado River Likely Future Without GRIC Settlement ..................................................................................3.14-16 Table 3.14-4 Reductions in Indian CAP Water Supplies During Times of Shortage on Colorado River (Likely Future with GRIC Settlement)............................................................................................3.14-17 Table 3.16-1 Frequency Occurrence of Excess Flows Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions.............................................................................................3.16-15 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xvi Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 74 of 1200 TABLE OF CONTENTS Table 3.16-2 Excess Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions; 75th Percentile Values for Selected Years (kaf)....................................3.16-20 Table 3.16-3 Excess Flows Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions; 90th Percentile Values for Selected Years (kaf)....................................3.16-21 Yellow-billed Cuckoos Survey Results................................................3.16-37 Table 3.16-4 Table 5-1 Participants with Reclamation Regarding the Interim Surplus Criteria Environmental Impact Statement Process......................................5-9 Table 5-2 Federal Register Notices Regarding Interim Surplus Criteria ..................5-12 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xvii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 75 of 1200 TABLE OF CONTENTS List of Figures Figure 1-1 Locations of Lee Ferry and Lees Ferry .......................................................1-6 Figure 1-2 Schematic of Colorado River Releases and Diversions ............................1-14 Figure 2-1 Baseline Surplus Trigger Elevations ...........................................................2-9 Figure 2-2 Basin States Alternative Surplus Trigger Elevations ................................2-12 Figure 2-3 Flood Control Alternative Surplus Trigger Elevations..............................2-16 Figure 2-4 Six States Alternative Surplus Trigger Elevations ....................................2-17 Figure 2-5 California Alternative Surplus Trigger Elevations....................................2-21 Figure 2-6 Shortage Protection Alternative Trigger Elevations..................................2-23 Figure 3.3-1 Natural Flow at Lees Ferry Stream Gage .................................................3.3-7 Figure 3.3-2 Historic Annual Flow at Lees Ferry Stream Gage ...................................3.3-8 Figure 3.3-3 Lake Powell and Glen Canyon Dam Important Operating Elevations ...............................................................................................3.3-19 Figure 3.3-4 Figure 3.3-5 Figure 3.3-6 rior 0 29, 2 nte Historic Lake Powell Water Levels........................................................3.3-20 17 the I t. of Lake Powell End-of-July Water ep . D Elevations er b Under Baseline th th ion v th vemValues and Representative Conditions; 90 , 50atand 10 n No Percentile N vajo hived o Traces .....................................................................................................3.3-21 Na arc ed in 86 End-of-July Water Elevations; Comparison of citLake Powell 4, 16 . 14oSurplus Alternatives to Baseline Conditions; 90th, 50th and 10th N Percentile Values ....................................................................................3.3-23 Figure 3.3-7 Lake Powell End-of-July Water Elevations; Comparison of Surplus Alternatives to Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 3695 Feet ........................................3.3-24 Figure 3.3-8 Lake Powell End-of-July Water Elevations; Comparison of Surplus Alternatives to Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 3612 Feet ........................................3.3-26 Figure 3.3-9 Histogram of Modeled Lake Powell Annual Releases (Water Years) 2002 to 2016 (85 Traces) .......................................................................3.3-28 Figure 3.3-10 Lake Mead and Hoover Dam Important Operating Elevations..............3.3-30 Figure 3.3-11 Historic Lake Mead Water Levels (Annual Highs and Lows) ...............3.3-32 Figure 3.3-12 Lake Mead End-of-December Water Elevations Under Baseline Conditions; 90th, 50th and 10th Percentile Values and Representative Traces .....................................................................................................3.3-33 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xviii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 76 of 1200 TABLE OF CONTENTS Figure 3.3-13 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives and Baseline Conditions; 90th, 50th and 10th Percentile Values ...................................................................................3.3-35 Figure 3.3-14 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives and Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1200 Feet ........................................3.3-36 Figure 3.3-15 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives to Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1083 Feet .......................................3.3-38 Figure 3.3-16 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives to Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1050 Feet ........................................3.3-39 Figure 3.3-17 Lake Mead End-of-December Water Elevations; Comparison of Surplus Alternatives to Baseline Conditions; Percentage of Values Greater than or Equal to Elevation 1000 Feet ........................................3.3-40 Figure 3.3-18 Colorado River Downstream of Havasu NWR Annual Flow Volume (af); Comparison of Surplus Alternatives toior Baseline Inter 17 Conditions; (0th, 50th, and 10th Percentile Values ...................................3.3-46 he Figure 3.3-19 t. of t , 20 Colorado River Annual Flow Volume Downstream of Havasu NWR; Dep mber 29 n v. Comparison of Surplus Alternativesve Baseline Conditions for atio on No to ajo N ................................................................................3.3-49 Modeled Year 2016 hived Nav ed in , arc Figure 3.3-20a citColorado 864 Seasonal Flows Downstream of Havasu NWR; 16 River . 14NoComparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ................................................................................3.3-50 Figure 3.3-20b Colorado River Seasonal Flows Downstream of Havasu NWR; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ................................................................................3.3-51 Figure 3.3-20c Colorado River Seasonal Flows Downstream of Havasu NWR; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ................................................................................3.3-52 Figure 3.3-20d Colorado River Seasonal Flows Downstream of Havasu NWR; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ................................................................................3.3-53 Figure 3.3-21 Colorado River Upstream of CRIR Diversion Annual Flow Volume (af); Comparison of Surplus Alternatives to Baseline Conditions; 90th, 50th, and 10th Percentile Values ..................................3.3-55 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xix Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 77 of 1200 TABLE OF CONTENTS Figure 3.3-22 Colorado River Annual Flow Volumes Upstream of Colorado River Indian Reservation; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2006 ........................................................3.3-57 Figure 3.3-23a Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ........................................................3.3-59 Figure 3.3-23b Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-60 Figure 3.3-23c Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-61 Figure 3.3-23d Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation;Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-62 Figure 3.3-24 Colorado River Downstream Palo Verde DiversionrDam Annual Flow ior Inte Baseline Volume (af); Comparison of Surplus Alternatives to 017 f the 9, 2 th th th pt. o Values ....................................3.3-65 Conditions; 90 50 and 10 Percentile er 2 De mb n v. atioFlow n Nove Downstream of Palo Verde Figure 3.3-25 Colorado River Annual Volumes ajo N ived o Irrigation av N Diversion;hComparison of Surplus Alternatives to ed in 864, arc citBaseline Conditions for Modeled Year 2006 .........................................3.3-66 16 . 14Figure 3.3-26aNoColorado River Seasonal Flows Downstream of Palo Verde Diversion Division; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-67 Figure 3.3-26b Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-68 Figure 3.3-26c Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-69 Figure 3.3-26d Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016........................................................3.3-70 Figure 3.3-27 Colorado River Below Mexico Diversion at Morelos Dam Annual Flow Volume (af); Comparison of Surplus Alternatives to Baseline Conditions 90th, 50th and 10th Percentile Values ....................................3.3-73 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xx Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 78 of 1200 TABLE OF CONTENTS Figure 3.3-28 Colorado River Annual Flow Volumes Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2006 ........................................................3.3-74 Figure 3.3-29a Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ........................................................3.3-76 Figure 3.3-29b Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ........................................................3.3-77 Figure 3.3-29c Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ........................................................3.3-78 Figure 3.3-29d Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ........................................................3.3-79 Figure 3.4-1 Arizona Projected Colorado River Water Demand Schedules ior Inter 17 (Full Surplus, Normal and Shortage Water Supply Conditions) ..............3.4-5 the Figure 3.4-2 Figure 3.4-3 Figure 3.4-4 t. of 9, 20 California Projected ColoradoDep Water er 2 . River b Demand Schedules on Shortage Water iand v Novem Supply Conditions) ..........3.4-11 (Full Surplus, Normal Nat n vajo ed o NevadaNa ProjectedrColorado River Water Demand Schedules chiv ed in 864Normal and Shortage Water Supply Conditions) ............3.4-13 it(Full Surplus, , a c -16 . 14 NoUpper Basin Depletion Projections (Based on 1998 Depletion Schedule) ................................................................................................3.4-15 Figure 3.4-5 Arizona Modeled Annual Depletions Under Baseline Conditions; 90th, 50th and 10th Percentile Values ....................................................3.4-19 Figure 3.4-6 Arizona Modeled Depletions Comparison of Surplus Alternatives to Baseline Conditions Years 2002 to 2016 ...............................................3.4-21 Figure 3.4-7 Arizona Modeled Depletions Comparison of Surplus Alternatives to Baseline Conditions Years 2017 to 2050 ...............................................3.4-22 Figure 3.4-8 Arizona Modeled Annual Depletions; Comparison of Surplus Alternatives to Baseline Conditions; 90th, 50th and 10th Percentile Values ....................................................................................3.4-25 Figure 3.4-9 California Modeled Annual Depletions Under Baseline Conditions; 90th, 50th and 10th Percentile Values .......................................................3.4-27 Figure 3.4-10 California Modeled Depletions; Comparison of Surplus Alternatives to Baseline Conditions; Years 2002 to 2016 ..............................................3.4-29 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxi Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 79 of 1200 TABLE OF CONTENTS Figure 3.4-11 California Modeled Depletions; Comparison of Surplus Alternatives to Baseline Conditions; Years 2017 to 2050 ..........................................3.4-30 Figure 3.4-12 California Modeled Annual Depletions; Comparison of Surplus Alternatives to Baseline Conditions; 90th, 50th and 10th Percentile Values ....................................................................................3.4-32 Figure 3.4-13 Nevada Modeled Annual Depletions Under Baseline Conditions; 90th, 50th and 10th Percentile Values ....................................................3.4-35 Figure 3.4-14 Nevada Modeled Depletions; Comparison of Surplus Alternatives to Baseline Conditions; Years 2002 to 2016 ..............................................3.4-37 Figure 3.4-15 Nevada Modeled Depletions; Comparison of Surplus Alternatives to Baseline Conditions; Years 2017 to 2050 ..............................................3.4-39 Figure 3.4-16 Nevada Modeled Annual Depletions; Comparison of Surplus Alternatives to Baseline Conditions; 90th, 50th and 10th Percentile Values ....................................................................................3.4-40 Figure 3.4-17 Mexico Modeled Annual Depletions Under Baseline Conditions; 90th, 50th and 10th Percentile Values .......................................................3.4-43 Figure 3.4-18 Figure 3.4-19 Figure 3.4-20 ior Mexico Modeled Depletions; Comparison of Surplus Alternatives to Inter 17 he Baseline Conditions; Years 2002 to 2016t..............................................3.4-45 , 20 . of ept r 29 . Mexico Modeled Depletions; D mbe ion v Comparison of Surplus Alternatives to atYears 2017 to ve ..............................................3.4-46 No 2050 Baseline Conditions; ajo N d on Nav hive a ed in Modeled rc citMexico6864, Annual Depletions; Comparison of Surplus 1 Alternatives to Baseline Conditions; 90th, 50th and 10th . 14NoPercentile Values ....................................................................................3.4-48 Figure 3.5-1 Historical Monthly Salinity Concentrations Below Glen Canyon Dam (1940-1995) .....................................................................................3.5-3 Figure 3.5-2 Historical Glen Canyon Dam and Imperial Dam Releases ......................3.5-4 Figure 3.5-3 Historical Salinity Concentrations of Releases from Glen Canyon, Hoover, and Imperial Dams .....................................................................3.5-5 Figure 3.5-4 Estimated Cost of Damages Associated with Increased Salinity Concentrations..........................................................................................3.5-8 Figure 3.5-5 Lake Mead End-of-Year Water Elevations; Comparison of Surplus Alternatives to Baseline Conditions; 50th Percentile Values..................3.5-21 Figure 3.6-1 Lake Powell Releases Probability of Occurrence of BHBF Flows ..........3.6-4 Figure 3.6-2 Lake Powell Releases Probability of Approximately 8.23 maf Annual Release .........................................................................................3.6-7 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 80 of 1200 TABLE OF CONTENTS Figure 3.9-1 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions 90th, 50th and 10th Percentile Values ......................................................3.9-15 Figure 3.9-2 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percent of Values Greater than or Equal to 3677 Feet msl ....................3.9-16 Figure 3.9-3 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percent of Values Greater than or Equal to 3612 Feet msl ....................3.9-19 Figure 3.9-4 Lake Mead End of December Water Elevations Comparison of Surplus Alternative to Baseline Conditions 90th, 50th and 10th Percentile Values........................................................3.9-23 Figure 3.9-5 Lake Mead End of December Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percent of Values Greater than or Equal to 1183 Feet msl ....................3.9-24 Figure 3.9-6 Lake Powell End of July Water Elevations ior Inter 17 Comparison of Surplus Alternatives to Baseline Conditions 0 f the 3626 Feet......................3.9-33 Percentage of Values Greater than or Equal to 29, 2 pt. o e r Figure 3.9-7 v. D mbe n e Lake Mead End of Decembern NovElevations Natio d o Water ajo Comparison of Surplus Alternatives to Baseline Conditions Nav archive d in 64Values Greater than or Equal to 1170 Feet......................3.9-36 e citPercentage of , 8 -16 . 14 Figure 3.10-1 NoGlen Canyon Powerplant/Annual Average Energy Production .............3.10-6 Figure 3.10-2 Hoover Powerplant Annual Average Energy Production.......................3.10-7 Figure 3.16-1 Probability of Occurrence of Excess Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions..............................................................................3.16-11 Figure 3.16-2 Potential Magnitude of Excess Flows Greater Than 250,000 af Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions ...............3.16-13 Figure 3.16-3 Potential Magnitude of Excess Flows Greater Than 1,000,000 af Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions ...............3.16-14 Figure 3.16-4 Potential Magnitude of Excess Flows Below Mexico Diversions at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 ......................................................3.16-16 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxiii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 81 of 1200 TABLE OF CONTENTS Figure 3.16- 5 Potential Magnitude of Excess Flows Below Mexico Diversion at Morelos Dam; Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2050 ......................................................3.16-17 Figure 3.16- 6 Potential Magnitude of Excess Flows To Mexico 90th and 75th Percentile Values ............................................................3.16-19 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxiv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 82 of 1200 TABLE OF CONTENTS List of Maps Map 1-1 Colorado River Drainage Basin...................................................................1-7 Map 1-2 Upper and Lower Basins of the Colorado River .......................................1-10 Map 1-3 Upper and Lower Division States of the Colorado River..........................1-12 Map 1-4 Lower Colorado River Dams.....................................................................1-18 Map 3.2-1 Area of Potential Effect ............................................................................3.2-2 Map 3.3-1 Colorado River Locations Selected for Modeling..................................3.3-44 Map 3.4-1 Colorado River Water Service Areas in the Lower Basin........................3.4-2 Map 3.5-1 Las Vegas Wash and SNWA Lake Mead Intake Facilities at Saddle Island ..........................................................................................3.5-14 Map 3.9-1 Lake Powell and Associated Shoreline Recreation Facilities ..................3.9-4 Map 3.9-2 Lake Mead and Associated Shoreline Recreation Facilities ..................3.9-11 Map 3.16-1 Colorado River Location Within Mexico...............................................3.16-6 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 83 of 1200 TABLE OF CONTENTS TABLE OF CONTENTS VOLUME II Attachment A - Long Range Operating Criteria Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of September 30, 1968 (p.l. 90-537) Attachment B - Environmental Guidelines for Transboundary Impacts Executive Order 12114 Guidance on NEPA Analyses for Transboundary Impacts, Council on Environmental Quality, 1997 Attachment C - Dams and Reservoirs Along the Lower Colorado River Attachment D - Glen Canyon Dam Operation Record of Decision Record of Decision based on Operation of Glen Canyon Dam Final Environmental Impact Statement, March 1995 ior Inter 17 Attachment E - Surplus Criteria Proposal by Six Statesthe , t. of Criteria 20 Proposal for Interim Lake Mead Reservoirep Operation er 29 Related to Surplus, .D b nv em Normal and Shortage Year Declarations, December 4, 1998 Natio d on Nov o avaj rchive Attachment F - SurplusN in Criteria Proposal by California a cited 16864, 14 Surplus Criteria-for Management of the Colorado River, Exhibit A to a draft document No. Terms for Quantification of Settlement Among the State of California, entitled Key IID, CVWD, and MWD Attachment G - Surplus Criteria Proposal by Pacific Institute Letter report dated February 15, 2000 Excerpts from September 8, 2000, letter of comment on the Colorado River Interim Surplus Criteria DEIS Attachment H - Lower Division Depletion Schedules Arizona’s Depletion Schedule Nevada’s Depletion Schedule California’s Depletion Schedule with Transfers California’s Depletion Schedule without Transfers COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxvi Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 84 of 1200 TABLE OF CONTENTS Attachment I - Draft Interim Surplus Guidelines Basin States Alternative Interim Surplus Guidelines Attachment J - Detailed Modeling Documentation Attachment K - Upper Division Depletion Schedule Depletion Schedule for Upper Division States, December 1999 Attachment L - Sensitivity Analysis Comparing Baseline with Transfers to Baseline Without Transfers Lake Powell Water Surface Elevations Lake Mead Water Surface Elevations Hoover Dam Flood Control Releases Water Supply Attachment M - Sensitivity Analysis of Modeled Lake Mead Water Level Protection Assumptions ior Inter 17 0 f the pt. o er 29, 2 Lake Powell Water Surface Elevations. De v mb ation RiverNove Attachment N - Comparison ajo N of Colorado on Flows Nav archived in Comparisond Flows64, cite of 168 Downstream of the Havasu National Wildlife Refuge Diversion 14Comparison of Flows Upstream of the Colorado River Indian Reservation Diversion No. Lake Mead Water Surface Elevations Comparison of Flows Downstream of the Palo Verde Irrigation District Diversion Comparison of Flows Below Morelos Dam Attachment O - Water Supply for Lower Division States Arizona Water Supply California Water Supply Nevada Water Supply COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxvii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 85 of 1200 TABLE OF CONTENTS Attachment P - Energy Analysis Worksheets Average Lake Mead Elevation and Comparison of SNWA Power Cost Average Lake Powell Elevation Glen Canyon Dam Discharge Multiplier and Powerplant Capacity vs. Elevation Hoover Powerplant Capacity vs. Elevation Glen Canyon Powerplant Summary of Average Annual Capacity and Energy Glen Canyon Powerplant Comparison to Baseline Conditions Hoover Powerplant Summary of Average Annual Capacity and Energy Hoover Powerplant Comparison to Baseline Conditions Attachment Q - Ten Tribes Depletion Schedule Tables of Water Demand Nodes, Water Rights and Depletions for Ten Tribes Partnership Members used in operational model Attachment R - Public Scoping Process ior Inter 17 e 20 of th Analysis of Public Scoping Meetings & Dept. Letters 9, Response er 2 . emb on v atiU.S. FishNovWildlife Service and National Attachment S - Correspondence with on and jo N Nava archived Marine Fisheries Services in cited 16864, Memorandum4- May 22, 2000 from Boulder Canyon Operations to Arizona 1 of No.Services Ecological Public Scoping Process Memorandum of June 5, 2000 from Interior Bureau of Reclamation Memorandum of August 14, 2000 from Interior to the Bureau of Reclamation Memorandum of August 31, 2000 from Reclamation to the U.S. Fish and Wildlife Service Memorandum of November 29, 2000 from Bureau of Reclamation to the U.S. Fish and Wildlife Service Attachment T - Consultation with Mexico Draft Authority and Assumptions Letter from Commissioner of Mexico Section of IBWC to United States Section of IBWC dated May 22, 2000 [in Spanish]. Letter from Commissioner of Mexico Section of IBWC to the United States Section of IBWC dated May 22, 2000, English translation. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxviii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 86 of 1200 TABLE OF CONTENTS Letter from Commissioner of Mexico Section of IBWC to United States Section of IBWC dated October 10, 2000 [in Spanish]. Letter from Commissioner of Mexico Section of IBWC to the United States Section of IBWC dated October 10, 2000, English translation. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxix Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 87 of 1200 TABLE OF CONTENTS TABLE OF CONTENTS VOLUME III INTRODUCTION TO VOLUME III .................................................................................. 1 PART A – PUBLIC HEARINGS AND ORAL COMMENTS ......................................A-1 PART B – COMMENT LETTERS AND RESPONSES................................................ B-1 Individuals Garcia.......................................................................................................................... B-3 Belles........................................................................................................................... B-4 Forbes Willson ............................................................................................................ B-5 Inskip........................................................................................................................... B-6 Miller........................................................................................................................... B-7 Zarbin.......................................................................................................................... B-9 ior Inter 17 0 f the American Water Resources, Inc. .............................................................................. B-11 pt. o er 29, 2 e v. D mb American Water Resources, Inc. .............................................................................. B-12 ation on Nove jo N American Water Resources, Inc. .............................................................................. B-14 Nava archive.d..................................................................... B-16 n Center for Biological Diversity, et,al1 ted i 6 ............................................................................................... B-22 ciof Wildlife864, Defenders -1 o. 14 Pacific Institute ......................................................................................................... B-34 N Organizations Southwest Rivers ...................................................................................................... B-51 Water User Agencies and Organizations Central Arizona Water Conservation District (CAWCD) ........................................ B-59 Coachella Valley Water District (CVWD) ............................................................... B-63 Colorado River Energy Distributors Association (CREDA) .................................... B-67 Colorado River Water Conservation District (CRWCD) ......................................... B-69 Cottonwood Creek Consolidated Irrigation Company (CCCIC).............................. B-71 Emery Water Conservancy District (EWCD)........................................................... B-72 Grand Water and Sewer (GW&S) ............................................................................ B-73 Imperial Irrigation District (IID)............................................................................... B-74 Irrigation and Electrical Districts Association of Arizona (I&EDAA) .................... B-77 Metropolitan Water District of Southern California (MWD) ................................... B-89 Mohave County Water Authority (MCWA)............................................................. B-95 Ouray Park Irrigation Company (OPIC)................................................................... B-98 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxx Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 88 of 1200 TABLE OF CONTENTS Water User Agencies and Organizations (Continued) Salt River Project (SRP) ........................................................................................... B-99 San Diego County Water Authority (SDCWA)...................................................... B-100 Southern California Edison Company (SCEC)....................................................... B-102 Southern Nevada Water Authority (SNWA) .......................................................... B-104 Uintah Water Conservancy District (UWCD) ........................................................ B-106 Union Park Water Authority (UPWA) ................................................................... B-109 Upper Colorado River Commission (UCRC) ......................................................... B-116 Local Agencies City of Phoenix, Office of the City Manager.......................................................... B-119 Grand County Council (Utah)................................................................................. B-122 State Agencies Arizona Power Authority (APA) ............................................................................ B-123 Arizona Power Authority (APA) ............................................................................ B-128 ior Arizona Department of Water Resources (ADWR) ............................................... B-130 Inter 17 Arizona Game and Fish Department (AG&FD)..................................................... B-136 0 f the pt. o er 29, 2 Colorado River Board of California (CRBC)e ......................................................... B-141 v. D v mb California Regional Water Quality on ati Control Boarde N n No (CRWQCB) ............................ B-142 Colorado Departmentavajo hived o (CDNR) ............................................ B-144 of Natural Resources c in N New Mexico Interstate 64, ar Commission (NMISC) .......................................... B-146 ited 68 Stream c Colorado River 4-1 1 Commission of Nevada (CRCN) .................................................. B-148 No. Commission (Nevada State Historic Preservation Colorado River Office-NSHPO).................................................................................................... B-151 New Mexico Environmental Department (NMED)................................................ B-154 Utah Department of Natural Resources, Division of Water Resources (UDNR, DWR) .................................................................................................... B-155 Office of Federal Land Policy (State of Wyoming) (WOFLP) .............................. B-157 Tribes Agua Caliente Band of Cahuilla Indians ................................................................ B-165 Hualapai Nation ...................................................................................................... B-167 Navajo Nation Department of Justice (excludes attachments) ............................... B-187 Navajo Tribal Utility Authority .............................................................................. B-191 Ute Mountain Ute Tribe ......................................................................................... B-193 Ten Tribes Partnership............................................................................................ B-194 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxxi Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 89 of 1200 TABLE OF CONTENTS Federal Agencies Bureau of Indian Affairs (BIA)............................................................................... B-221 Bureau of Indian Affairs, Navajo Region ............................................................... B-223 Environmental Protection Agency (EPA)............................................................... B-225 U.S. Fish and Wildlife ............................................................................................ B-238 International Boundary and Water Commission, United States Section (IBWC, U.S. Section) .......................................................................................... B-278 National Park Service (NPS) .................................................................................. B-281 Western Area Power Administration (WAPA)....................................................... B-286 Western Area Power Administration (WAPA)....................................................... B-287 Western Area Power Administration (WAPA)....................................................... B-289 Mexican Agencies/Organizations Autonomous University of Baja California (AUBC) ............................................. B-291 International Boundary and Water Commission, Mexican Section (IBWC, Mexican) ................................................................................................ B-294 Mexicali Business Coordinating Council (MBCC) ................................................ B-296 ior Mexicali Economic Development Council (MEDC).............................................. B-298 Inter 17 e National Water Commission (NWC)...................................................................... B-300 of th , 20 9 pt. . De ember 2 nv Additional Tribe atio Nov ajo N ived on Nav d in 64, arch Kaibab Band of Paiute Indians ............................................................................... B-303 cite 168 14No. Oral Comments Noble....................................................................................................................... B-305 1 This letter was submitted by the following organizations: Defenders of Wildlife Environmental Defense El Centro de Derecho Ambiental e Integracion Economica del Sur, A.C. Friends of Arizona Rivers Glen Canyon Action Network Glen Canyon Institute Pacific Institute for Studies in Development, Environment and Security Sierra Club Fred Cagle Jaqueline Garcia-Hernandez COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxxii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 90 of 1200 TABLE OF CONTENTS TABLE OF CONTENTS EXECUTIVE SUMMARY S.1 INTRODUCTION AND BACKGROUND.........................................................................1 S.1.1 INTRODUCTION ................................................................................................. 1 S.1.2 PROPOSED FEDERAL ACTION ........................................................................ 4 S.1.3 BACKGROUND ................................................................................................... 4 S.1.3.1 Long-Range Operating Criteria ....................................................... 5 S.1.3.2 Annual Operating Plan ....................................................................6 S.1.4 PURPOSE AND NEED FOR ACTION................................................................ 7 S.1.5 RELATIONSHIP TO UNITED STATES–MEXICO WATER TREATY ........... 8 S.1.6 RELATED AND ON-GOING ACTIONS ............................................................ 8 S.1.6.1 California’s Colorado River Water Use Plan .................................. 8 S.1.6.1.1 Imperial Irrigation District/San Diego County Water Authority Water Transfer ................................................................ 9 or S.1.6.1.2 All-American and Coachella Canal Lining iProjects ..................... 10 Inter 17 0 f the S.1.6.2 Glen Canyon Dam Operations.......................................................10 pt. o er 29, 2 e S.1.6.2.1 Adaptive Management Program.................................................... 11 v. D mb ation on Nove S.1.6.2.2 Beach/Habitat-Building Flows and Beach/HabitatoN avaj rch Flows........................................................................ 11 NMaintenanceived in Temperature Control at Glen Canyon Dam................................... 12 a S.1.6.2.3cited 864, 16Actions Related to the Biological and Conference Opinion S.1.6.3 14No. on Lower Colorado River Operations and Maintenance ............... 12 S.1.6.4 Lower Colorado River Multi-Species Conservation Program ...... 13 S.1.6.5 Secretarial Implementation Agreement Related to California’s Colorado River Water Use Plan ................................13 S.1.6.6 Offstream Storage of Colorado River Water and Development and Release of Intentionally Created Unused Apportionment in the Lower Division States ................................ 14 S.2 ALTERNATIVES .............................................................................................................. 14 S.2.1 DEVELOPMENT OF ALTERNATIVES ........................................................... 14 S.2.1.1 Origins of California, Six States and Basin States Alternatives....................................................................................14 S.2.1.2 Utilization of Proposals from Basin States.................................... 15 S.2.2 DESCRIPTION OF ALTERNATIVES............................................................... 16 S.2.2.1 No Action Alternative and Baseline Conditions ........................... 16 S.2.2.1.1 Approach to Surplus Water Determination ................................... 16 S.2.2.1.2 70R Baseline Surplus Triggers ...................................................... 16 S.2.2.2 Basin States Alternative (Preferred Alternative) ...........................17 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxxiii Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 91 of 1200 TABLE OF CONTENTS S.2.2.2.1 S.2.2.2.2 S.2.2.3 S.2.2.3.1 S.2.2.3.2 S.2.2.4 S.2.2.4.1 S.2.2.4.2 S.2.2.5 S.2.2.5.1 S.2.2.5.2 S.2.2.6 S.2.2.6.1 S.2.2.6.2 Approach to Surplus Water Determination ................................... 17 Basin States Alternative Surplus Triggers.....................................18 Flood Control Alternative.............................................................. 18 Approach to Surplus Water Determination ................................... 18 Flood Control Alternative Surplus Triggers..................................18 Six States Alternative .................................................................... 18 Approach to Surplus Water Determination ................................... 18 Six States Alternative Surplus Triggers......................................... 19 California Alternative ....................................................................19 Approach to Surplus Water Determination ................................... 19 California Alternative Surplus Triggers ........................................ 19 Shortage Protection Alternative..................................................... 20 Approach to Surplus Water Determination ................................... 20 Shortage Protection Alternative Surplus Triggers......................... 20 S.3 SUMMARY OF ENVIRONMENTAL CONSEQUENCES .............................................20 S.3.1 USE OF MODELING TO IDENTIFY POTENTIAL FUTURE COLORADO RIVER SYSTEM CONDITIONS ................................................ 20 S.3.2 BASELINE CONDITIONS................................................................................. 20 r S.3.3 S.3.4 terio ,2 er 29 In IMPACT DETERMINATION APPROACH ......................................................21 017 f the pt. o ve n No PERIOD OF ANALYSIS ....................................................................................21 v. De mb n Natio d o ................................................................. 21 S.3.5 POTENTIALLY ajo v AFFECTED AREA e in Na OF archiv ALTERNATIVES TO BASELINE d , SURPLUS S.3.6 COMPARISON 4 cite 1686 CONDITIONS .....................................................................................................22 14No. S.3.6.1 Effects on Reservoir Surface Elevations and River Flows............ 22 S.3.6.2 S.3.6.3 S.3.6.3.1 S.3.6.3.2 S.3.6.3.3 S.3.6.3.4 S.3.6.3.5 S.3.6.3.6 S.3.6.3.7 Summary of Environmental Impacts............................................. 24 Environmental Commitments........................................................24 Water Quality ................................................................................ 25 Riverflow Issues ............................................................................25 Aquatic Resources .........................................................................25 Special-Status Species ...................................................................26 Recreation...................................................................................... 26 Cultural Resources.........................................................................26 Transboundary Impacts .................................................................26 S.4 OTHER NEPA CONSIDERATIONS................................................................................ 27 S.4.1 CUMULATIVE IMPACTS................................................................................. 27 S.4.2 RELATIONSHIP BETWEEN SHORT-TERM USES OF THE ENVIRONMENT AND LONG-TERM PRODUCTIVITY................................ 28 S.4.3 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES ...................................................................................................... 28 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxxiv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 92 of 1200 TABLE OF CONTENTS S.5 CONSULTATION AND COORDINATION....................................................................29 S.5.1 GENERAL PUBLIC INVOLVEMENT ACTIVITIES....................................... 29 S.5.1.1 Project Scoping.............................................................................. 29 S.5.1.2 Public Review of DEIS ................................................................. 30 S.5.2 FEDERAL AGENCY COORDINATION .......................................................... 31 S.5.2.1 National Park Service .................................................................... 31 S.5.2.2 U.S. Section of the International Boundary and Water Commission ........................................................................ 31 S.5.2.3 U.S. Bureau of Indian Affairs........................................................ 31 S.5.2.4 U.S. Fish and Wildlife Service Including Endangered Species Act Compliance ................................................................ 31 S.5.2.5 National Marine Fisheries Service ................................................ 33 S.5.2.6 National Historic Preservation Act Compliance ...........................33 S.5.3 TRIBAL CONSULTATION ...............................................................................34 S.5.4 STATE AND LOCAL WATER AND POWER AGENCIES COORDINATION ............................................................................................... 34 S.5.5 NON-GOVERNMENTAL ORGANIZATIONS COORDINATION ................. 35 S.5.6 S.5.7 S.5.8 erior t. of r 29, 20 SUMMARY OF COORDINATION ep CONTACTS .............................................36 v. D mbe ation on Nove FEDERAL REGISTER NOTICES .......................................................................36 jo N Nava archived in cited 16864, 14No. nt MEXICO CONSULTATION .............................................................................. 36 17 the I COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS TOC - xxxv Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 93 of 1200 ACRONYMS AND ABBREVIATIONS 4.4 Plan California 4.4 Plan °C degrees Celsius AAC All-American Canal CAP Central Arizona Project AAQS ambient air quality standards CA PLAN ADEQ Arizona Department of Environmental Quality California’s Colorado River Water Use Plan CAWCD Arizona Department of Water Resources Central Arizona Water Conservation District CBRFC Colorado Basin River Forecast Center CDFG Colorado Department of Fish and Game Council on Environmental Quality ADWR af acre-feet afy acre-feet per year AGFD Arizona Game and Fish Department CEQ ALP Animas-La Plata Project CFR AMP Glen Canyon Dam Adaptive Management Program cfs AMWG AOP APE erior t t. of r 29, 20 Cleanep Water Federal Water Pollution D be Adaptive Management Work ion v. Control Act Act Novem at Group on jo N Nava archivedthe Compact Colorado River Compact of Annuald in Plan 1992 cite Operating64, 168Effect 4Area . 1 United States Army Corps of Corps No of Potential AWBA Arizona Water Banking Authority BA cubic Int per second he feet 17 Engineers Biological Assessment Basin States Code of Federal Regulations Council Advisory Council on Historic Preservation Colorado River Basin States Court United States Supreme Court BCO Biological and Conference Opinion CRBPA Colorado River Basin Project Act of 1968 BCPA Boulder Canyon Project Act of 1928 CRFWLS Colorado River Front Work and Levee System BHBF Beach/Habitat-Building Flow CRIR Colorado River Indian Reservation BIA Bureau of Indian Affairs CRIT Colorado River Indian Tribes BLM Bureau of Land Management CRMWG BMI Basic Management, Inc. Colorado River Management Work Group BO Biological Opinion CRSP Colorado River Storage Project COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS ACR-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 94 of 1200 ACRONYMS AND ABBREVIATIONS CRSPA Colorado River Storage Project Act of 1956 CRSS Colorado River Simulation System CRSSez A simplified version of CRSS CUP Central Utah Project CVWD Coachella Valley Water District Decree The 1964 U. S. Supreme Court Decree, Arizona v. California DEIS Draft Environmental Impact Statement DO DOE Gulf Gulf of California GWh gigawatt-hour HAVFISH Lake Havasu Fishery Improvement Project HCP Habitat Conservation Plan IBWC International Boundary and Water Commission United States and Mexico IID Imperial Irrigation District Indian American Indian Interior U.S. Department of the Interior dissolved oxygen ISM Indexed Sequential Method United States Department of Energy ITA Indian Trust Asset kaf thousand acre-feet EA Environmental Assessment kV kilovolt(s) EIR Environmental Impact Report LCRAS EIS EPA ESA o F rior nt Colorado River Lowere 17 the I , 20System Accounting 9 of ept. ber 2 v. D m Lower Colorado River MultiLCRMSCP ation on Nove N Species Conservation Program Environmentalvajo Protection ed in a 4, archiv Agency N Lake Mead National LMNRA cited 1686 Recreation Area 4Endangered Species Act of o. 1 as amended N 1973, Long-Range Operating Criteria LROC Environmental Impact Statement degrees Fahrenheit LVWCAMP FEMA maf million acre-feet mafy million acre-feet per year Mexico United Mexican States μg/g micrograms per gram μg/l microgram per liter milligram per liter mg/m3 Finding of No Significant Impact municipal and industrial milligrams per cubic meter Federal Emergency Management Agency FONSI Las Vegas Wash Comprehensive Adaptive Management Plan M&I Final Environmental Impact Statement Las Vegas Wash Coordination Committee mg/l FEIS LVWCC Forum Colorado River Basin Salinity Control Forum FWCA Fish and Wildlife Coordination Act of 1934 GCNRA Glen Canyon National Recreation Area GRIC Gila River Indian Community COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS ACR-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 95 of 1200 ACRONYMS AND ABBREVIATIONS MOA Memorandum of Agreement P.L. Public Law MOC Memorandum of Clarification PM particulate matter MODE Main Outlet Drain Extension ppb parts per billion MOU Memorandum of Understanding ppm parts per million PPR present perfected rights mph miles per hour PVID Palo Verde Irrigation District MSCP Multi-Species Conservation Program Reclamation United States Bureau of Reclamation msl mean sea level RM river mile MW megawatts RMP Resource Management Plan MWD Metropolitan Water District of Southern California ROD Record of Decision MWh megawatt-hours San Carlos San Carlos Apache Tribe NAAQS National Ambient Air Quality Standards SCP Colorado River Basin Salinity Control Program NDEP Nevada Division of Environmental Protection SDCWA NDOW NEPA NFWG NHPA San Diego County Water ior Int r 7 Authority e e 01 f th pt. o SaferDrinking Water Act of 29, 2 e SDWA Nevada Division of Wildlife v. D mbe ation on Nove 1974 National Environmental Policy oN avaj United States Secretary of the Namended rchivedSecretary Act of 1969, as in Interior ited 6864, a c Native Fish 1 4- Work Group 1 Section 7 of the Federal Section 7 No. National Historic Preservation Endangered Species Act Act of 1966 Section 10 Section 10 of the Federal Endangered Species Act Northerly International Boundary Service United States Fish and Wildlife Service NIIP Navajo Indian Irrigation Project SHPO State Historic Preservation Officer NMFS National Marine Fisheries Service SIB Southerly International Boundary NPS National Park Service SLD Shoreline Development Value NWR National Wildlife Refuge SNWA O&M operation and maintenance Southern Nevada Water Authority Pacific Institute Pacific Institute for Studies in Development Environment and Security SNWS Southern Nevada Water System NHWZ New High Water Zone NIB COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS ACR-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 96 of 1200 ACRONYMS AND ABBREVIATIONS SRPMIC Salt River Pima Maricopa Indian Community USGS United States Geological Survey SWP California State Water Project USIBWC TDS total dissolved solids United States Section of the International Boundary and Water Commission Treaty U.S.-Mexico Water Treaty of 1944 Western Western Area Power Administration UIIP Uintah Indian Irrigation Project WSCC Western States Coordinating Council 2 Umho/cm micromhos per centimeter squared ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS ACR-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 97 of 1200 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 98 of 1200 1 INTRODUCTION AND BACKGROUND 1.1 INTRODUCTION The Secretary of the United States Department of the Interior (Secretary), acting through the United States Bureau of Reclamation (Reclamation), is considering the adoption of specific interim criteria under which surplus water conditions may be declared in the lower Colorado River Basin during a 15-year period that would extend through 2016. The Secretary is vested with the responsibility of managing the mainstream waters of the lower Colorado River pursuant to applicable federal law. This responsibility is carried out consistent with a collection of documents known as the Law of the River, which includes a combination of federal and state statutes, interstate compacts, court decisions and decrees, an international treaty, contracts with the Secretary, operating criteria, regulations and administrative decisions (see Section 1.3.2.1 for a further discussion of the Law of the River). The long-term Colorado River system management objectives are terior n to: 7 he I . of t r 29, 201 pt • Minimize flood damages from river flows, . De be ion v Novem at withnthe 1964 Decree in Arizona v. • Release water only inajo N accordance o Nav archived California (Decree), in cited 16864, • Protect and enhance the environmental resources of the basin, 14No. • Provide reliable delivery of water for beneficial consumptive use, • Increase flexibility of water deliveries under a complex allocation system, • Encourage efficient use of renewable water supplies, • Minimize curtailment to users who depend on such supplies, and • Consider power generation needs. As the agency that is designated to act on the Secretary’s behalf with respect to these matters, Reclamation is the Lead Federal Agency for the purposes of NEPA compliance for the development and implementation of the proposed interim surplus criteria. The National Park Service (NPS) and the United States Section of the International Boundary and Water Commission (USIBWC) are cooperating agencies for purposes of assisting with the environmental analysis. This Final Environmental Impact Statement (FEIS) has been prepared pursuant to the National Environmental Policy Act of 1969 (NEPA), as amended, and the Council on Environmental Quality’s (CEQ) Regulations for Implementing the Procedural COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 99 of 12001 CHAPTER INTRODUCTION Provisions of NEPA (40 Code of Federal Regulations [CFR] Parts 1500 through 1508). This FEIS has been prepared to address the formulation and evaluation of specific interim surplus criteria and to identify the potential environmental effects of implementing such criteria. This FEIS addresses the environmental issues associated with, and analyzes the environmental consequences of various alternatives for specific interim surplus criteria. The alternatives addressed in this FEIS are those Reclamation has determined would meet the purpose and need for the federal action and represent a broad range of the most reasonable alternatives. 1.1.1 PROPOSED FEDERAL ACTION The proposed federal action is the adoption of specific interim surplus criteria pursuant to Article III(3)(b) of the Criteria for Coordinated Long-Range Operation of the Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of September 30, 1968 (Long-Range Operating Criteria [LROC]). The interim surplus criteria would be used annually to determine the conditions under which the Secretary may declare the availability of surplus water for use within the states of Arizona, California and Nevada. The criteria must be consistent with both therDecree entered by ior n California Iv. te 17 and the e the United States Supreme Court in 1964 in the case of Arizona of th 29, 20 LROC. The interim surplus criteria would remainept. in effect forrdeterminations made . D of mbe through calendar year 2015 regardingatioavailability vesurplus water through calendar the n v No year 2016, subject to five-yearajo N conducted concurrently with LROC reviews, v reviews ived on n Na as part and would be applied each year , archof the Annual Operating Plan (AOP). ted i 4 ci 1686 . 141.1.2 BACKGROUND No Pursuant to Article II(B)2 of the Decree, if there exists sufficient water available in a single year for pumping or release from Lake Mead to satisfy annual consumptive use in the States of California, Nevada, and Arizona in excess of 7.5 million acre-feet (maf), such water may be determined by the Secretary to be available as “surplus” water. The Secretary is authorized to determine the conditions upon which such water may be made available. The Colorado River Basin Project Act of 1968 (CRBPA) directs the Secretary to adopt criteria for coordinated long-range operation of reservoirs on the Colorado River in order to comply with and carry out the provisions of the Colorado River Compact of 1922 (Compact), the Colorado River Storage Project Act of 1956 (CRSPA), the Boulder Canyon Project Act of 1928 (BCPA) and the United States-Mexico Water Treaty of 1944 (Treaty). These criteria are the LROC, described in detail later in this chapter and reproduced in Attachment A. The Secretary sponsors a formal review of the LROC every five years. The LROC provide that the Secretary will determine the extent to which the reasonable consumptive use requirements of mainstream users in Arizona, California and Nevada (the Lower Division states) can be met. The LROC define a normal year as a year in COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 100 of 1200 CHAPTER 1 INTRODUCTION which annual pumping and release from Lake Mead will be sufficient to satisfy 7.5 maf of consumptive use in accordance with the Decree. A surplus year is defined as a year in which water in quantities greater than normal (i.e., greater than 7.5 maf) is available for pumping or release from Lake Mead pursuant to Article II(B)2 of the Decree after consideration of relevant factors, including the factors listed in the LROC. Surplus water is available to agencies which have contracted with the Secretary for delivery of surplus water, for use when their water demand exceeds their basic entitlement, and when the excess demand cannot be met within the basic apportionment of their state. Water apportioned to, but unused by one or more Lower Division states can be used to satisfy beneficial consumptive use requests of mainstream users in other Lower Division states as provided in Article II(B)(6) of the Decree. Pursuant to the CRBPA, the LROC are utilized by the Secretary, on an annual basis, to make determinations with respect to the projected plan of operations of the storage reservoirs in the Colorado River Basin. The AOP is prepared by Reclamation, acting on behalf of the Secretary, in consultation with representatives of the Colorado River Basin states (Basin States) and other parties, as required by federal law. The interim surplus criteria would serve to implement the provisions of Article III(3)(b) of the LROC on an annual basis in the determinations made by the Secretary as part of the AOP process. ior Inter 17 1.1.3 PURPOSE OF AND NEED FOR ACTION 0 f the pt. o er 29, 2 e D b To date, the Secretary has applied factors, n v. to those found tio including but m aannual on Novenot limited availability of in N Article III(3)(b)(i-iv) of the LROC, in vajo ed determinations of the surplus quantities of water for pumpingior release from Lake Mead. As a result of in Na 4, arch v ted 6 and c experience86 through preparation of AOPs, particularly during recent actual operating i -1 o. 14 years when there has been increasing demand for surplus water, the Secretary has N determined that there is a need for more specific surplus criteria, consistent with the Decree and applicable federal law, to assist in the Secretary’s annual decision making during an interim period. For many years, California has been diverting more than its normal 4.4 maf apportionment. Prior to 1996, California utilized unused apportionments of other Lower Division states that were made available by the Secretary. Since 1996, California has also utilized surplus water made available by Secretarial determination. California is in the process of developing the means to reduce its annual use of Colorado River water to 4.4 maf. Arizona is approaching full use of its apportionment and Nevada was expected to reach its apportionment in 2000. Additionally, through adoption of specific interim surplus criteria, the Secretary will be able to afford mainstream users of Colorado River water, particularly those in California who currently utilize surplus flows, a greater degree of predictability with respect to the likely existence, or lack thereof, of surplus conditions on the river in a given year. Adoption of the interim surplus criteria is intended to recognize California’s plan to reduce reliance on surplus deliveries, to assist California in moving COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 101 of 1200 CHAPTER 1 INTRODUCTION toward its allocated share of Colorado River water, and to avoid hindering such efforts. Implementation of interim surplus criteria would take into account progress, or lack thereof, in California’s efforts to achieve these objectives. The surplus criteria would be used to identify the specific amount of surplus water which may be made available in a given year, based upon factors such as the elevation of Lake Mead, during a period within which demand for surplus Colorado River water will be reduced. The increased level of predictability with respect to the prospective existence and quantity of surplus water would assist in planning and operations by all entities that receive surplus Colorado River water pursuant to contracts with the Secretary. 1.1.4 RELATIONSHIP TO THE UNITED STATES-MEXICO WATER TREATY Under Article 10(a) of the Treaty, the United Mexican States (Mexico) is entitled to an annual amount of 1.5 maf of Colorado River water. Under Article 10(b) of the Treaty, Mexico may schedule up to an additional 0.2 maf when “there exists a surplus of waters of the Colorado River in excess of the amount necessary to satisfy uses in the United States.” This is in addition to surplus determinations for the Lower Division states made pursuant to Article II(2)(b) of the Decree and Article III(3)(B) of the LROC. The proposed action is not intended to identify, or change in any manner,rconditions when ior Inte surplus Mexico may schedule this additional 0.2 maf. Under current e f th practice, 017 2 pt o er 2 control releases are declarations under the Treaty for Mexico are declared .when flood 9, D .aree emb this practice. made. Modeling assumptions used ination v this EIS based Nov upon Reclamation is currently engaged in discussions with Mexico through the IBWC on the ajo N ived on av effects of the proposedn N 4, arch d i action. te ci 86 4-16 . 1COOPERATING AGENCIES 1.1.5 LEADNo AND The Secretary is vested with the responsibility of managing the mainstream waters of the lower Colorado River pursuant to federal law. This responsibility is carried out consistent with the Law of the River. Reclamation, as the agency that is designated to act on the Secretary’s behalf with respect to these matters, is the Lead Federal Agency for the purposes of NEPA compliance for the development and implementation of the proposed interim surplus criteria. The NPS and the USIBWC are cooperating agencies for purposes of assisting with the environmental analysis. The NPS administers three areas of national significance along the Colorado River: Glen Canyon National Recreation Area (GCNRA), Grand Canyon National Park and Lake Mead National Recreation Area (LMNRA). The NPS administers recreation, cultural and natural resources in these areas from offices at Page and Grand Canyon National Park, Arizona and Boulder City, Nevada, respectively. The NPS also grants and administers concessions for the operation of marinas and other recreation facilities at Lake Powell and Lake Mead. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 102 of 1200 CHAPTER 1 INTRODUCTION The International Boundary and Water Commission United States and Mexico (IBWC) is a bi-national organization responsible for administration of the provisions of the Treaty, including the Colorado River waters allocated to Mexico, protection of lands along the Colorado River from floods by levee and floodway projects, resolution of international boundary water sanitation and other water quality problems, and preservation of the river as the international boundary. The IBWC consists of the United States Section and the Mexico Section, which have their headquarters in the adjoining cities of El Paso, Texas and Ciudad Juarez, Chihuahua, respectively. 1.2 SUMMARY OF CONTENTS OF THIS FEIS Following is a brief description of the topics presented in the three volumes that comprise this FEIS, including a summary of the chapters in Volume I. Volume I of this FEIS (this volume) describes the proposed action, the alternatives considered, the analysis of potential effects of interim surplus criteria on Colorado River operation and associated resources, and environmental commitments associated with the action alternatives. The contents of the chapters in this volume are as follows: Chapter 1, Introduction, includes the following: identification of the rior e purpose of and Intinformation need for the interim surplus criteria being considered; background 017 f the concerning the apportionment of Colorado River water and therphysical facilities pt. o e 29, 2 . De b associated with the Colorado River system; and discussion of the institutional ion v Novem at is managed. Chapter 1 also discusses framework within which the vajosystem ed on river N Na thatarchiavrelationship to the proposed interim surplus n previous and ongoing iactions , have cited 16864 criteria. 4- No. 1 Chapter 2, Description of Alternatives, describes the process of formulating alternatives and presents the reservoir operation strategies of each alternative under consideration. A summary table of potential environmental consequences of action alternatives is provided at the end of Chapter 2. Chapter 3, Affected Environment and Environmental Consequences, presents the analysis of baseline conditions along with potential impacts that could result from implementation of the interim surplus criteria alternatives under consideration. The discussion addresses both the affected environment (existing conditions within the area of potential effect) and environmental consequences (potential effects of the interim surplus criteria alternatives that could occur as compared to baseline projections). Also discussed, in Section 3.17, are environmental commitments that Reclamation would undertake if interim surplus criteria are implemented. Chapter 4, Other NEPA Considerations, discusses cumulative impacts, the relationship between short-term use and long-term productivity, and irreversible and irretrievable commitments of resources affected by the interim surplus criteria under consideration. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 103 of 1200 CHAPTER 1 INTRODUCTION Chapter 5, Consultation and Coordination, describes the public involvement process, including public notices, scoping meetings, and hearings. This chapter also describes the coordination with federal and state agencies, Indian Tribes, and Mexico during the preparation of this document and any permitting or approvals that may be necessary for implementation of proposed interim surplus criteria. In addition to the above, Volume I includes a list of acronyms used throughout this document, a glossary of commonly used terms, a list of references cited in the FEIS, a list of persons contributing to the preparation of the FEIS, a distribution list of agencies, organizations and persons receiving copies of the document, and an index. Volume II contains attachments which are comprised of documents and other supporting material that provide detailed historical background and/or technical information concerning this proposed action. Volume III contains reproductions of letters from the public resulting from the public review of the Draft Environmental Impact Statement (DEIS) and Reclamation’s responses to the comments received. r 1.3 WATER SUPPLY MANAGEMENT AND ALLOCATION terio e In o th 29 2017 .thef Colorado,River Basin from This section summarizes the water supply availablept De in mber n of natural runoff, its distribution under the iLaw v. the River, and the reservoirs and at o Nove diversion facilities through which the waterd on is administered from Lake Powell to ajo N ive supply Nav Mexico. d in 64, arch cite 168 141.3.1 COLORADO RIVER SYSTEM WATER SUPPLY No. The Colorado River serves as a source of water for irrigation, domestic and other uses in the States of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming and in Mexico. The Colorado River also serves as a source of water for a variety of recreational and environmental benefits. The Colorado River Basin is located in the southwestern United States, as shown on Map 1-1, and occupies a total area of approximately 250,000 square miles. The Colorado River is approximately 1400 miles in length and originates along the Continental Divide in Rocky Mountain National Park in Colorado. Elevations in the Colorado River Basin range from sea level to over 14,000 feet above mean sea level (msl) in the mountainous headwaters. Figure 1-1 Loc ations of Lee F err y and Lees Ferr y Climate varies significantly throughout the Colorado River Basin. Most of the Basin is comprised of desert COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-6 Figure 1-1 Locations of Lee Ferry and Lees Ferry Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 104 of 1200 CHAPTER 1 INTRODUCTION Map 1-1 Colorado River Drainage Basin ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 105 of 1200 CHAPTER 1 INTRODUCTION or semi-arid rangelands, which generally receive less than 10 inches of precipitation per year. In contrast, many of the mountainous areas that rim the northern portion of the Basin receive, on average, over 40 inches of precipitation per year. Most of the total annual flow in the Colorado River Basin is a result of natural runoff from mountain snowmelt. Because of this, natural flow is very high in the late spring and early summer, diminishing rapidly by mid-summer. While flows in late summer through autumn sometimes increase following rain events, natural flow in the late summer through winter is generally low. Major tributaries to the Colorado River include the Green, San Juan, Yampa, Gunnison and Gila Rivers. The annual flow of the Colorado River varies considerably from year to year. The natural flow at the Lees Ferry gaging station (see Figure 1-1), located 17 river miles (RMs) below Glen Canyon Dam, has varied annually, from 5 maf to 23 maf. Natural flow represents an estimate of flows that would exist without reservoir regulation, depletion, or transbasin diversion by man. Most of the lower Colorado River’s water, or about 88 percent of the annual natural supply, flows into the Lower Basin from the Upper Basin and is accounted for at Lee Ferry, Arizona. The remaining 12 percent of the lower Colorado River’srwater is erio attributed to sidewash inflows due to rainstorms and tributarye Int in the 7 h rivers 201 Lower Basin. of t The Lower Colorado River Basin’s mean annual tributary inflow is , ept. ber 29 about 1.38 maf, .D m excluding the intermittent Gila River inflow.vActual tributary inflows are highly ation on Nove N variable from year to year. vajo ed in Na rchiv ited 6864, a c 1.3.2 APPORTIONMENT OF WATER SUPPLY -1 o. 14 N This section summarizes the Colorado River apportionments of the Basin States and Mexico stemming from the Law of the River, past and current river diversions and consumptive use and projected future depletions. The apportionments of the Basin States are stipulated in terms of consumptive use, which consists of diversions minus return flows to the river system. 1.3.2.1 THE LAW OF THE RIVER As stated previously, the Secretary is vested with the responsibility to manage the mainstream waters of the lower Colorado River pursuant to applicable federal law. The responsibility is carried out consistent with a body of documents referred to as the Law of the River. The Law of the River encompasses numerous operating criteria, regulations and administrative decisions included in federal and state statutes, interstate compacts, court decisions and decrees, an international treaty, and contracts with the Secretary. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 106 of 1200 CHAPTER 1 INTRODUCTION Particularly notable among these documents are: 1) The Colorado River Compact of 1922, which apportioned beneficial consumptive use of water among the Upper and Lower Basins; The Boulder Canyon Project Act of 1928 (BCPA), which authorized construction of Hoover Dam and the All-American Canal (AAC), also authorized the Lower Division states to enter into an agreement apportioning the water, required that water users in the Lower Basin have a contract with the Secretary, and established the responsibilities of the Secretary to direct, manage and coordinate the operation of Colorado River dams and related works in the Lower Basin; 2) The California Seven Party Water Agreement of 1931, which established the relative priorities of rights among major users of Colorado River water in California who claimed rights at that time; 3) The United States-Mexico Water Treaty of 1944 and subsequent specific applications through minutes of the IBWC related to the quantity and quality of Colorado River water delivered to Mexico; rior Inte 4) The Upper Colorado River Basin Compact of 1948), which apportioned the f the 9, 2017 o Upper Basin water supply; 2 ept. .D ber ion vAct Novem 5) The Colorado River Storageat jo N Project on of 1956 (CRSPA), which authorized a Nava archived comprehensive water development plan for the Upper Basin that included the in cited 1686Canyon Dam; construction of Glen 4, 14No. United States Supreme Court Decree, Arizona v. California 6) The 1964 (Decree), which confirmed the apportionment of the Lower Basin tributaries was reserved for the exclusive use of the states in which the tributaries are located; confirmed the Lower Basin mainstem apportionments of 4.4 maf for use in California, 2.8 maf for use in Arizona and 0.3 maf for use in Nevada; addressed the reservation of water for American Indian (Indian) reservations and other federal reservations in California, Arizona and Nevada; and confirmed the significant role of the Secretary in managing the mainstream of the Colorado River within the Lower Basin; 7) The Colorado River Basin Project Act of 1968,which authorized construction of a number of water development projects including the Central Arizona Project (CAP) and required the Secretary to develop the LROC; 8) The Colorado River Basin Salinity Control Act of 1974, which authorized a number of salinity control projects and provided a framework to improve and meet salinity standards for the Colorado River in the United States and Mexico; and COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 107 of 1200 CHAPTER 1 INTRODUCTION 9) The Grand Canyon Protection Act of 1992, which addressed the protection of resources in Grand Canyon National Park and Glen Canyon National Recreation Area. Documents which are generally considered as part of the Law of the River include, but are not limited to, documents listed in Table 1-1. Among other provisions of applicable federal law, NEPA and the Endangered Species Act (ESA) provide a statutory overlay on certain actions taken by the Secretary. For example, as noted in Section 1.1, preparation of this FEIS has been undertaken pursuant to NEPA. 1.3.2.2 APPORTIONMENT PROVISIONS The initial apportionment of water from the Map 1-2 Upper and Lower Basins Colorado River was determined as part of the of the Colorado River 1922 Colorado River Compact. The Compact divided the Colorado River into two sub-basins, the Upper Basin and the Lower Basin (see Map 1-2). The Upper Basin includes those parts of the States of Colorado, Utah, Wyoming, Arizona and New Mexico ior Inter 17 within and from which waters drain naturally 0 f the into the Colorado River above Lee Ferry pt. o er 29, 2 e D mb (Arizona). The Lower Basin includes those v. ation on Nove oN parts of the States of Arizona, California, ed avaj rchiv NUtah within and Nevada, New Mexico iand a d n citenaturally 64, into the from which waters 168drain 14Colorado River system below Lee Ferry No. (Arizona). The Compact also divided the seven Basin States into the Upper Division and the Lower Division (see Map 1-3). The Upper Division consists of the states of Wyoming, Utah, Colorado and New Mexico. The Lower Division consists of the states of Arizona, California and Nevada. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 108 of 1200 CHAPTER 1 INTRODUCTION Table 1-1 Documents Included in the Law of the River The River and Harbor Act, March 3, 1899 The Reclamation Act of June 17, 1902 Reclamation of Indian Lands in Yuma, Colorado River and Pyramid Lake Indian Reservations Act of April 21, 1904 Yuma Project authorized by the Secretary of the Interior on May 10, 1904, pursuant to Section 4 of the Reclamation Act of June 17, 1902 Warren Act of February 21, 1910 Protection of Property Along the Colorado River Act of June 25, 1910 Patents and Water-Right Certificates Acts of August 9, 1912 and August 26, 1912 Yuma Auxiliary Project Act of January 25, 1917 Availability of Money for Yuma Auxiliary Project Act of February 11, 1918 Sale of Water for Miscellaneous Purposes Act of February 25, 1920 Federal Power Act of June 10, 1920 The Colorado River Compact of November 24, 1922 The Colorado River Front Work and Levee System Acts of March 3, 1925 and January 21,1927-June 28, 1946 The Boulder Canyon Project Act of December 21, 1928 The California Limitation Act of March 4, 1929 The California Seven Party Agreement of August 18, 1931 The Parker and Grand Coulee Dams Authorization of August 30, 1935 The Parker Dam Power Project Appropriation Act of May 2, 1939 The Reclamation Project Act of August 4, 1939 The Boulder Canyon Project Adjustment Act of July 19, 1940 The Flood Control Act of December 22, 1944 United States-Mexico Water Treaty of February 3, 1944 Gila Project Act of July 30, 1947 The Upper Colorado River Basin Compact of October 11, 1948 Consolidated Parker Dam Power Project and Davis Dam Project Act of May 28, 1954 Palo Verde Diversion Dam Act of August 31, 1954 Change Boundaries, Yuma Auxiliary Project Act of February 15, 1956 The Colorado River Storage Project Act of April 11, 1956 Water Supply Act of July 3, 1958 Boulder City Act of September 2, 1958 Report of the Special Master, Simon H. Rifkind, Arizona v. California, et al., December 5, 1960 United States Supreme Court Decree, Arizona v. California, March 9, 1964 International Flood Control Measures, Lower Colorado River Act of August 10, 1964 Southern Nevada (Robert B. Griffith) Water Project Act of October 22, 1965 The Colorado River Basin Project Act of September 30, 1968 Criteria for the Coordinated Long Range Operation of Colorado River Reservoirs, June 8, 1970 Supplemental Irrigation Facilities, Yuma Division Act of September 25, 1970 Minutes 218, March 22, 1965; 241, July 14, 1972, (replaced 218); and 242, August 30, 1973, (replaced 241) of the International Boundary and Water Commission, pursuant to the United States-Mexico Water Treaty of 1944 The Colorado River Basin Salinity Control Act of June 24, 1974 United States Supreme Court Supplemental Decrees, Arizona v. California, January 9, 1979 and April 16, 1984 Hoover Power Plant Act of August 17, 1984 The Numerous Colorado River Water Delivery and Project Repayment Contracts with the States of Arizona and Nevada, cities, water districts and individuals Hoover and Parker-Davis Power Marketing Contracts Reclamation States Emergency Drought Relief Act of 1991 Grand Canyon Protection Act of October 30, 1992 43 CFR 414 Offstream Storage of Colorado River Water in the Lower Division States 43 CFR 417 Lower Basin Water Conservation Measures ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 109 of 1200 CHAPTER 1 INTRODUCTION The Compact apportioned to each Basin, in perpetuity, the exclusive beneficial consumptive use of 7.5 maf of water per year. In addition to this apportionment, Article III(b) gives the Lower Basin the right to increase its beneficial consumptive use by 1.0 maf per annum. The Compact also stipulates in Article III(d) that the states of the Upper Division will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75 maf for any period of 10 consecutive years. Map 1-3 Upper and Lower Division States of the Colorado River The Compact, in Article VII, states that nothing in the Compact shall be construed as affecting the obligations of the United States to Indian Tribes. While the rights of most tribes to Colorado River water were subsequently adjudicated, some Tribal rights remain unadjudicated. ior Inter 17 e of th 29, 20 1.3.2.2.1 Upper Division State Apportionments pt. . De ber ion v Novem Nat The Compact apportioned 7.5 maf of water d on vajo hive in perpetuity to the Upper Basin. The a Upper Basin Compactin N apportioned among the four Upper Division states the following arc ited quantity,of consumptive use apportioned to and available for c total 16864 percentages of the 4use each year byo. 1Upper Basin under the Upper Colorado River Basin Compact and N the remaining after deduction of the use, not to exceed 50,000 acre-feet (af) per annum, made in the State of Arizona: • Wyoming 14.00 percent • Utah 23.00 percent • Colorado 51.75 percent • New Mexico 11.25 percent Map 1- 3 U pper and Lower Di vi sion States of the C olor ado Ri ver In 1988, a determination of Upper Basin water supply was made in Hydrologic Determination: Water Availability from Navajo Reservoir and the Upper Colorado River Basin for Use in New Mexico (Interior, 1989). In consideration of Article 3(d) of the Compact and accounting for the decrease in the average natural flow of the Colorado River since the signing of the Compact in 1922, the Determination concluded that Upper Basin annual water depletion can reasonably be expected to reach six maf. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 110 of 1200 CHAPTER 1 INTRODUCTION 1.3.2.2.2 Lower Division State Apportionments If sufficient mainstream water is available for release, as determined by the Secretary, to satisfy 7.5 maf of consumptive use in the Lower Division states, then the amount of Colorado River water apportioned for consumptive use in each Lower Division state is expressed in terms of a fixed amount in each state, subject to varying provisions at times of surpluses or shortages. These apportionments are: California, 4.4 maf; Arizona, 2.8 maf; and Nevada, 0.3 maf, totaling 7.5 maf. Figure 1-2 presents a schematic of the operation of the Colorado River, primarily in the Lower Basin. The apportionments to the Lower Division states were established by the BCPA and confirmed by the Decree. If water apportioned for use in a Lower Division state is not consumed by that state in any year, the Secretary may release the unused water for use in another Lower Division state. Consumptive use by a Lower Division state includes delivered water that is stored offstream for future use by that state or another state. All mainstream Colorado River waters apportioned to the Lower Basin, except for a few thousand af apportioned for use in the State of Arizona, have been fully allocated to specific entities and, except for certain federal establishments, placed under permanent water delivery contracts with the Secretary for irrigation or domestic use. These entities include irrigation districts, water districts, municipalities, Indian Tribes, r io public Inter 17 with e institutions, private water companies and individuals. Federal establishments 0 of th 2 Decree p II(D) of the 9, 2 are not federal reserved rights established pursuant to Articlet. e r be v. D required to have a contract with the Secretary, but the vem allocated to a federal ation on No water establishment is included withinjo N ved va the apportionment of the Lower Division state in which in Na 4, archi the federal establishment is located. ted ci 1686 . 14The highest priority Colorado River water rights are present perfected rights (PPRs), No which the Decree defines as those perfected rights existing on June 25, 1929, the effective date of the BCPA. The Decree also recognizes Federal Indian reserved rights for the quantity of water necessary to irrigate all the practicably irrigable acreage on five Indian reservations along the lower Colorado River. The Decree defines the rights of Indian and other federal reservations to be federal establishment PPRs. PPRs are important because in any year in which less than 7.5 maf of Colorado River water is available for consumptive use in the Lower Division states, PPRs will be satisfied first, in the order of their priority without regard to state lines. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 111 of 1200 CHAPTER 1 INTRODUCTION Figure 1-2 Schematic of Colorado River Releases and Diversions Trans-basin Diversions Evaporation Upper Basin Uses above Glen Canyon Dam Evaporation Tributary Gains above Hoover Dam Lower Basin Users above Hoover Dam ior Inter 17 f the 9, 20 pt. o er Evaporation Southern Nevada 2 De mb Users n v. atio Nove ajo N ived on Tributary Gains below Nav d in 64, arch Hoovercite Dam 168 . 14No Laughlin Area NV Users Bullhead City Area AZ Users CAP MWD California Irrigation Districts, Other Users Other AZ Users Delivery to Mexico COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-14 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 112 of 1200 CHAPTER 1 INTRODUCTION Waters available to a Lower Division state within its apportionment, but having a priority date later than June 25, 1929, have been allocated by the Secretary to water users within that state after consultation with the state as required by the BCPA. 1.3.2.2.3 Mexico Apportionment Mexico has an annual apportionment of 1.5 maf of Colorado River water, based on the provisions of the Treaty. Mexico may also receive additional water under two conditions. First, when surplus water exists in excess of the amount that can be beneficially used by the Basin States, Mexico is apportioned up to an additional 200,000 af of water which Mexico is allowed to schedule throughout the year in accordance with Article 15 of the Treaty. Second, when high runoff and flooding occur on the Colorado or Gila Rivers that is substantially more than can be put to beneficial use by the Lower Division states, such runoff flows into Mexico. Deliveries to Mexico are subject to reduction under extraordinary drought conditions or serious accident to the irrigation system in the United States. In such cases, deliveries to Mexico, as provided for under the Treaty, could be reduced in proportion to the reduction faced by users in the United States. rior Inte 1 As part of this NEPA documentation, international impacts are addressed in Section f the Abroad of7 20 Major 3.16 pursuant to Executive Order 12114-Environmentalo ept. Effects 29, r D be Federal Actions, January 4, 1997, and the n v.1, 1997 CEQ Guidelines on NEPA tioJuly n Nov m a(See AttachmenteB for copies of these Analyses for Transboundary Impacts. o jo N Nava archived documents.) in d cite 16864, 141.3.3 LONG-RANGE OPERATING CRITERIA No. The CRBPA required the Secretary to adopt operating criteria for the Colorado River by January 1, 1970. The LROC, adopted in 1970 (see Attachment A), control the operation of the Colorado River reservoirs in compliance with requirements set forth in the Compact, the CRSPA, the BCPA, the Treaty and other applicable federal laws. Under the LROC, the Secretary makes annual determinations in the AOP (discussed in the following section) regarding the availability of Colorado River water for deliveries to the Lower Division states (Arizona, California and Nevada). A requirement to equalize the active storage between Lake Powell and Lake Mead when there is sufficient storage in the Upper Basin is also included in the LROC, as required by the CRBPA. A more complete discussion of this concept is presented in Section 1.4.2 of this document. Section 602 of the CRBPA, as amended, provides that the LROC can only be modified after correspondence with the governors of the seven Basin States and appropriate consultation with such state representatives as each governor may designate. The LROC call for formal reviews at least every five years. The reviews are conducted as a public involvement process and are attended by representatives of federal agencies, the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-15 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 113 of 1200 CHAPTER 1 INTRODUCTION seven Basin States, Indian Tribes, the general public including representatives of the academic and scientific communities, environmental organizations, the recreation industry and contractors for the purchase of federal power produced at Glen Canyon Dam. Past reviews have not resulted in any changes to the criteria. 1.3.4 ANNUAL OPERATING PLAN The CRBPA requires preparation of an AOP for the Colorado River reservoirs that guides the operation of the system for the water year. The AOP describes how Reclamation will manage the reservoirs over a 12-month period, consistent with the LROC and the Decree. The AOP is prepared annually by Reclamation in cooperation with the Basin States, other federal agencies, Indian tribes, state and local agencies and the general public, including governmental interests as required by federal law. As part of the AOP process, the Secretary makes annual determinations regarding the availability of Colorado River water for deliveries to the Lower Division states as described below. 1.3.4.1 NORMAL, SURPLUS AND SHORTAGE DETERMINATIONS The Secretary is required to determine when normal, surplus or shortagerconditions rio occur in the lower Colorado River, based on various factors he Inte storage and including t 017 hydrologic conditions in the Colorado River Basin. pt. of 29, 2 e v. D v ber ion determinesem sufficient mainstream water at Normal conditions exist when the Secretary on No that a o N ved vof jannual iconsumptive use in the Lower Division states. is available to satisfy 7.5 Na maf h ed in its 4, arc ituse all of 86apportioned water for the year, the Secretary may allow c If a state will not -16 other states of No. 14 Division to use the unused apportionment, provided that the the Lower use is covered under a contract with the consuming entity. Surplus conditions exist when the Secretary determines that sufficient mainstream water is available for release to satisfy consumptive use in the Lower Division states in excess of 7.5 maf annually. This excess consumptive use is surplus and is distributed for use in California, Arizona and Nevada in allocations of 50, 46 and four percent, respectively. As stated above, if a state will not use all of its apportioned water for the year, the Secretary may allow other states of the Lower Division to use the unused apportionment, provided that the use is covered under a contract with the consuming entity. Surplus water under the Decree, for use in the Lower Division states, was made available by the Secretary in calendar years 1996, 1997, 1998, 1999 and 2000. Deliveries of surplus water to Mexico in accordance with the Treaty were made in calendar years 1983-1988, 1997, 1998, 1999 and 2000. Shortage conditions exist when the Secretary determines that insufficient mainstream water is available to satisfy 7.5 maf of annual consumptive use in the Lower Division states. When making a shortage determination, the Secretary must consult with various COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-16 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 114 of 1200 CHAPTER 1 INTRODUCTION parties as set forth in the Decree and consider all relevant factors as specified in the LROC (described above), including Treaty obligations, the priorities set forth in the Decree, and the reasonable consumptive use requirements of mainstream water users in the Lower Division. The Secretary is required to first provide for the satisfaction of the PPRs in the order of their priority, then to users who held contracts on September 30, 1968 (up to 4.4 maf in California), and finally to users who had contracted on September 30, 1968, when the CAP was authorized. To date, a shortage has never been determined. 1.3.5 SYSTEM RESERVOIRS AND DIVERSION FACILITIES The Colorado River system contains numerous reservoirs that provide an aggregate of approximately 60 maf of active storage. Lake Powell and Lake Mead provide approximately 85 percent of this storage. Upper Basin reservoirs provide approximately 31.2 maf of active storage, of which Lake Powell provides 24.3 maf. The other major storage reservoirs in the Upper Basin include Flaming Gorge Reservoir on the Green River, Navajo Reservoir on the San Juan River, and Blue Mesa Reservoir on the Gunnison River. rior The Lower Basin dams and reservoirs include Hoover, Davis e InParker dams, shown and te f th to 9, 2017of active on Map 1-4. Hoover Dam created Lake Mead and can store up 2 26.2 maf pt. o er . De to re-regulate Hoover Dam’s storage. Davis Dam was constructed byion v Reclamation emb at of 1.5 n NovMexico. Davis Dam creates releases and to aid in the annual jdelivery d o maf to oN Navamafrofhive storage. Parker Dam forms Lake Havasu Lake Mohave and provides 1.8 a c active in cit isd 168 by , from which water e pumped 64 both Metropolitan Water District of Southern 14California (MWD) and the CAP. Parker Dam re-regulates releases from Davis Dam No. and from the United States Army Corps of Engineers’ (Corps) Alamo Dam on the Bill Williams River, and in turn releases water for downstream use in the United States and Mexico. Other Lower Basin mainstream reservoirs, listed in Table 1-2, are operated primarily for the purpose of river flow regulation to facilitate diversion of water to Arizona, California and Mexico. Diversion facilities of the Lower Division states typically serve multiple entities. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-17 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 115 of 1200 CHAPTER 1 INTRODUCTION Map 1-4 Lower Colorado River Dams ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-18 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 116 of 1200 CHAPTER 1 INTRODUCTION Table 1-2 summarizes the Colorado River storage facilities (i.e., dams and reservoirs) and major diversion dams from Lake Powell downstream to Morelos Dam. Attachment C, Dams and Reservoirs Along the Lower Colorado River, describes the reservoirs and the role that each plays in the operation of the Colorado River system. Table 1-2 Colorado River Storage Facilities and Major Diversion Dams from Lake Powell to Morelos Dam Facility Reservoir Glen Canyon Dam Lake Powell Hoover Dam Lake Mead Davis Dam Lake Mohave Parker Dam Lake Havasu Headgate Rock Dam Lake Moovalya Morelos Dam impoundment Unnamed impoundment 1 Location Upstream of Lee Ferry, Utah, Arizona Nevada and Arizona near Las Vegas, 270 miles downstream of Glen Canyon Dam 70 miles downstream of Hoover Dam 150 miles downstream of Hoover Dam 164 miles downstream of Hoover Dam 209 miles downstream of Hoover Dam 290 miles downstream of Hoover Dam near Imperial Dam 290 miles downstream of Hoover Dam 300 miles downstream of Hoover Dam 320 miles downstream of Hoover Dam Storage Capacity (af) 24,322,000 Live 27,400,000 Live 1,818,000 648,000 N.A. 3 N.A. 3 r terio InN.A.3 17 Palo Verde Diversion Unnamed 0 f the Dam impoundment pt. o er 29, 2 e v. D Senator Wash Senator Wash 13,800 mb 2 ation on Nove regulating facility Reservoir N vajo ed in Na 4, archiv d Unnamed Imperial Dam 1000 cite impoundment 86 4-16 1 Unnamed Laguna Dam No. 700 1 2 3 Lake Havasu provides a relatively constant water level for pumped diversions by MWD and CAP. Senator Wash Reservoir is an offstream reservoir with a pumping/generating plant. Run-of-river diversion structure. In Nevada, the State’s consumptive use apportionment of Colorado River water is used almost exclusively for municipal and industrial (M&I) purposes. About 90 percent of this water is diverted from Lake Mead at a point approximately five miles northwest of Hoover Dam at Saddle Island by the Southern Nevada Water Authority (SNWA) facilities. The remainder of Nevada’s diversion occurs below Davis Dam in the Laughlin area. There are several points of diversion in Arizona. Up to 50,000 af of water is diverted above Lee Ferry. The intake for the CAP is the pumping plant on Lake Havasu below the confluence of the Bill Williams River. Irrigation water for the Fort Mojave Indian Reservation, near Needles, California, is pumped from wells. Irrigation water for the Colorado River Indian Reservation near Parker, Arizona, is diverted at Headgate Rock COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-19 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 117 of 1200 CHAPTER 1 INTRODUCTION Dam, which was constructed for that purpose. A river pumping plant in the Cibola area provides water to irrigate lands adjacent to the river. The last major diversion for Arizona occurs at Imperial Dam, where water is diverted into the Gila Gravity Main Canal for irrigation for the Gila and Wellton-Mohawk projects and into the AAC for subsequent release into the Yuma Main Canal for the Yuma Project and the City of Yuma. California receives most of its Colorado River water at three diversion points: MWD’s pumping plant on Lake Havasu; the Palo Verde Irrigation and Drainage District’s diversion at the Palo Verde Diversion Dam near Blythe, California; and the AAC diversion at Imperial Dam. 1.3.6 FLOOD CONTROL OPERATION Under the BCPA, flood control was specified as the project purpose having first priority for the operation of Hoover Dam. Subsequently, Section 7 of the Flood Control Act of 1944 established that the Secretary of War (now the Corps) will prescribe regulations for flood control for projects authorized wholly or partially for such purposes. The Los Angeles District of the Corps published the current flood control regulations in rior the Water Control Manual for Flood Control, Hoover Dam he ILake Mead Colorado and nte 17 ft River, Nevada and Arizona (Water Control Manual) dated December 20 pt. o er 29, 1982. The Field e b Working Agreement between Corps and on v. D for the i Reclamationvem flood control operation of at by theNo Control Manual, was signed Hoover Dam and Lake Mead, asjo N prescribed on Water Nava controlived is the result of a coordinated effort on February 8, 1984. in flood arch plan The cited 16864, between the Corps and -Reclamation; however, the Corps is responsible for providing the flood controlo. 14 N regulations and has authority for final approval. The Secretary is responsible for operating Hoover Dam in accordance with these regulations. Any deviation from the flood control operating criteria must be authorized by the Corps. Flood control operation of Lake Mead was established to deal with two distinct types of flooding—snowmelt and rain. Snowmelt constitutes about 70 percent of the annual runoff in the Upper Basin. Lake Mead’s uppermost 1.5 maf of storage capacity, between elevations 1219.61 feet above msl and 1229.0 feet msl, are allocated exclusively to control floods from rain events. The flood control regulations set forth two primary criteria to deal with snowmelt: • Preparatory reservoir space requirements, applicable from August 1 through December 31; and • Application of runoff forecasts to determine releases, applicable from January 1 through July 31. In preparation for each year’s seasonal snow accumulation and associated runoff, the first criterion provides for progressive expansion of the total Colorado River system COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-20 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 118 of 1200 CHAPTER 1 INTRODUCTION reservoir space during the latter months of each year. Required system space increases from 1.5 maf on August 1 to 5.35 maf on January 1. Required flood storage space up to 3.85 maf can be located within Lake Powell and in specified Upper Basin reservoirs. Space-building releases from Lake Mead are made when needed to meet the required August 1 to January 1 flood control space. Space-building releases beyond the minimum requirements of the Corps’ Water Control Manual (often described as anticipatory flood control releases) may be considered by the Secretary. The Secretary takes into consideration the following: 1) the channel capacity of the river below Davis Dam; 2) the channel capacity and channel maintenance of the river below the Southerly International Boundary (SIB) (through the IBWC); and 3) power plant maintenance requirements at Hoover, Davis and Parker dams. Between January 1 and July 31, flood control releases, based on the maximum forecasted inflow into Lake Mead, may be required to prevent filling of Lake Mead beyond its 1.5 maf minimum flood control space. Each month, runoff forecasts are developed by the National Weather Service’s Colorado Basin River Forecast Center. The required monthly releases from Hoover Dam are determined based on available space in Lake Mead and upstream reservoirs and the maximum forecasts of inflow into Lake Mead. Average monthly releases are determined each month erioapply only to and r Int River Floodway the current month. Release rates, developed pursuant to thehe Colorado 017 of t ,2 Protection Act of 1986, are discussed in SectionDept. 3.6.4.1. er 29 v. mb ation on Nove 1.3.7 HYDROPOWER GENERATION jo N Nava archived d in , Reclamation is cite -16by64 authorized 8 legislation to produce electric power at each of the major 14 Colorado River system dams, except Navajo Dam. Power generation at the Glen No. Canyon Dam Powerplant requires the water surface elevation of Lake Powell to be above 3490 feet msl. Water is released from Glen Canyon Dam Powerplant into the Colorado River through a combination of the eight main generating units. The minimum water surface elevation of Lake Mead necessary for power generation at Hoover Powerplant is approximately 1083 feet msl. Water is released from Hoover Powerplant to Lake Mohave through a combination of the 17 main generating units. Water is then released at Davis Dam Powerplant into the river through a combination of the five generators. Parker Dam is the last major regulating and reservoir facility on the Lower Colorado River. All releases scheduled from Parker Dam are in response to downstream water orders and reservoir regulation requirements and pass through a combination of its four generators. Although Reclamation is the federal agency authorized to produce power at the major Colorado River system dams, Western Area Power Administration (Western) is the federal agency authorized to market this power. Western enters into electric service contracts on behalf of the United States with public and private utility systems for distribution of hydroelectric power produced at Reclamation facilities. The released COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-21 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 119 of 1200 CHAPTER 1 INTRODUCTION water generates power, but water is not to be released from any Colorado River facility for the sole purpose of generating power. Under operating agreements with Western, Reclamation is subject to downstream water requirements to meet the power generation schedules of Hoover, Parker and Davis dams. Western produces these schedules in accordance with existing electric service contracts, recognizing Reclamation’s release requirements on the lower Colorado River (i.e., based on downstream delivery requirements) from the respective reservoirs. 1.4 RELATED AND ONGOING ACTIONS A number of ongoing and new actions proposed by Reclamation and other entities are related to the development of interim surplus criteria and the analysis contained in this document. This section describes these actions and their relationship to the development of interim surplus criteria. The following actions have been described in environmental documents, consultation packages under Section 7 of the ESA, or as project planning documents. Where appropriate, this FEIS incorporates by reference information contained in these documents. The documents described below are available for public inspection upon request at Reclamation offices in Boulder City, Nevada; Salt Lake City, Utah; and Phoenix and Yuma, Arizona. erior Int 0 f the PLAN17 1.4.1 CALIFORNIA’S COLORADO RIVERept. o USE 9, 2 WATER r 2 v. D v mbe o ation (CA Plan),ewhich was formerly known as California’s Colorado River Water N Plan on N vajo Use ived the California 4.4 Planin Na 4.4 Plan, calls for conservation measures to be put in place or the arch cited 16864, that will reduce California’s dependency on surplus Colorado River water. Surplus 4water is requiredo. 1 N to meet California’s current needs until implementation of the conservation measures can take place. During the period ending in 2016, the State of California has indicated that it intends to reduce its reliance on Colorado River water to meet its water needs above and beyond its 4.4-maf apportionment. It is important for the long-term administration of the system to bring the Lower Basin uses into accordance with the Lower Basin normal apportionment. In order to achieve its goals, California has expressed a need to continue to rely in some measure on the existence of surplus Colorado River water through 2016. These interim surplus criteria could aid California and its primary Colorado River water users as California reduces its consumptive use to 4.4 maf while ensuring that the other Basin States will not be placed at undue risk of future shortages. The CA Plan contains numerous water conservation projects, intrastate water exchanges, and groundwater storage facilities. The CA Plan is related to the implementation of the interim surplus criteria in the ways discussed below. First, implementation of the CA Plan is necessary to ensure the Colorado River system can meet the normal year deliveries in the Lower Basin over the long term. Failure of California to comply with the CA Plan places at risk the objective of providing reliable COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-22 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 120 of 1200 CHAPTER 1 INTRODUCTION delivery of water for beneficial consumptive use to Lower Basin users. Therefore, the Secretary may condition the continuation of interim surplus criteria for the entire period through 2016 on a showing of satisfactory progress in implementing the CA Plan. Regardless of which alternative is ultimately selected, failure of California to carry out the CA Plan may result in termination or suspended application of the proposed interim surplus criteria. In that event, the Secretary would fashion appropriate surplus criteria for the remaining period through 2016. For example, the Basin States Alternative presented in Chapter 2 anticipates that the 70R strategy would be used in the event of such a reversion. Second, from the perspective of the State of California, because of the linkage between various elements of the CA Plan and the quantities of water involved, a reliable supply of interim surplus water from the Colorado River is an indispensable pre-condition to successful implementation of the CA Plan. From the standpoint of environmental documentation and compliance, the CA Plan and its various elements have been, or will be, addressed under separate federal and/or state environmental reporting procedures. 1.4.1.1 IMPERIAL IRRIGATION DISTRICT/SAN DIEGO COUNTY WATER AUTHORITY ior Inter 17 ATER TRANSFER W the 20 of ept. ber 29, v. County Water Authority (SDCWA) The Imperial Irrigation District (IID)/San DiegoD em ation on Nova part of the CA Plan. SDCWA N water transfer is one of the intrastate exchanges that is vajo ed has negotiated an agreement for therlong-term transfer of conserved water from the IID. in Na 4, a chiv d cite 168 IID Under the proposed contract,6 customers would undertake water conservation efforts to reduce theirNo. of 4 use 1 Colorado River water. Water conserved through these efforts would be transferred to SDCWA. The agreement sets the transfer quantity at a maximum of 200 kaf/year. After at least 10 years of primary transfers, an additional discretionary component not to exceed 100 kaf/year may be transferred to SDCWA, MWD of Southern California, or Coachella Valley Water District in connection with the settlement of water rights disputes between IID and these agencies. The initial transfer target date is 2002, or whenever the conditions necessary for the agreement to be finalized are satisfied or waived, whichever is later. This transfer is being addressed in an ongoing EIS/EIR and involves the change in point of delivery of up to 300 kaf/year from Imperial Dam to Parker Dam. 1.4.1.2 ALL-AMERICAN AND COACHELLA CANAL LINING PROJECTS Two other components of the CA Plan having effects on the river are the All-American and Coachella Canal Lining Projects (the Coachella Canal is a branch of the AAC). These two similar actions involve the concrete lining of unlined portions of the canals to conserve water presently being lost as seepage from the earthen reaches. Together the projects involve a change in point of delivery from Imperial Dam to Parker Dam that totals 93.7 kaf/year, 67.7 kaf/year for the AAC and 26 kaf/year for the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-23 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 121 of 1200 CHAPTER 1 INTRODUCTION Coachella Canal. The effects of this change in point of delivery are being addressed in the Secretarial Implementation Agreement EA and BA (described in Section 1.4.5). The Record of Decision (ROD) for the All-American Canal Lining Project was approved on July 29, 1994. Construction is expected to begin in 2001. A draft EIS/EIR for the Coachella Canal Lining Project was released on September 22, 2000 for public review. 1.4.2 GLEN CANYON DAM OPERATIONS Glen Canyon Dam is operated consistent with the CRSPA and the LROC, which were promulgated in compliance with Section 602 of the CRBPA. Glen Canyon Dam is also operated consistent with the 1996 ROD on the Operation of Glen Canyon Dam (Attachment C) developed as directed under the Grand Canyon Protection Act of 1992. The minimum release from Lake Powell, as specified in the LROC, is 8.23 maf per year. In years with very low inflow, or in years when Lake Powell is significantly drawn down, annual releases of 8.23 maf from Lake Powell are made. The LROC also require that, when Upper Basin storage is greater than the storage required under Section 602(a) of the CRBPA, releases from Lake Powell will periodically be governed by the objective to maintain, as nearly as practicable, active storage inior Mead equal er Lake In provision in the to the active storage in Lake Powell. Because of this equalization t f the result 017 LROC, changes in operations at Lake Mead will, inpt. o years, 29, 2in changes in some . De ber annual release volumes from Lake Powell.n It is through this mechanism that delivery of io v Novem at on surplus water from Lake Meadajo N v can influence the operation of Glen Canyon Dam. ved iexists insufficient storage in the Upper Basin, Na Equalization is not required when arch d in 64, there citeof the CRBPA. per Section 602(a) -168 No. 14 In acknowledgement that the operation of Glen Canyon Dam, as authorized, to maximize power production was having a negative impact on downstream resources, the Secretary determined in July 1989 that an Environmental Impact Statement (EIS) should be prepared. The Operation of Glen Canyon Dam EIS developed and analyzed alternative operation scenarios that met statutory responsibilities for protecting downstream resources and achieving other authorized purposes, while protecting Native American interests. A final EIS was completed in March 1995, and the Secretary signed a ROD on October 8, 1996. Reclamation also consulted with the United States Fish and Wildlife Service (Service) under the ESA and incorporated the Service’s recommendations into the ROD. The ROD describes criteria and plans for dam operations and includes other measures to ensure Glen Canyon Dam is operated in a manner consistent with the Grand Canyon Protection Act of 1992. Among these are an Adaptive Management Program, beach/habitat-building flows (BHBFs), beach/habitat-maintenance flows, and further study of temperature control. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-24 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 122 of 1200 CHAPTER 1 INTRODUCTION The ROD is based on the EIS, which contains descriptions and analyses of aquatic and riparian habitats below Glen Canyon Dam, effects of Glen Canyon Dam release patterns on the local ecology, cultural resources, sedimentation processes associated with the maintenance of backwaters and sediment deposits along the river, Native American interests, and relationships between release patterns and the value of hydroelectric energy produced. Analyses of effects on other resources within the affected area are also included. Additional information concerning the operation of Glen Canyon Dam is contained in Section 3.3. 1.4.2.1 ADAPTIVE MANAGEMENT PROGRAM The Adaptive Management Program (AMP) provides a process for assessing the effects of current operations of Glen Canyon Dam on downstream resources and using the results to develop recommendations for modifying operating criteria and other resource management actions. This is accomplished through the Adaptive Management Work Group (AMWG), a federal advisory committee. The AMWG consists of stakeholders that are federal and state resource management agencies, representatives of the seven Basin States, Indian Tribes, hydroelectric power marketers, environmental and conservation organizations and recreational and other interest groups. The duties of the r AMWG are in an advisory capacity only. Coupled with this advisory irole are long-term ter o Inof resource conditions e monitoring and research activities that provide a continual record of th 29 2017 and new information to evaluate the effectiveness epthe operational, modifications. of t. D er v. mb t on aFiLOWSon Nove /HABITAT-MAINTENANCE 1.4.2.2 BEACH/HABITAT-Bvajo N a UILDINGhived AND BEACH FLOWS ed in N arc cit 864, -16 BHBF releases are scheduled high releases of short duration that are in excess of power o. 14 N plant capacity required for dam safety purposes and are made according to certain specific criteria as described in Section 3.6.2. These BHBFs are designed to rebuild high elevation sandbars, deposit nutrients, restore backwater channels, and provide some of the dynamics of a natural system. The first test of a BHBF was conducted in Spring of 1996. Beach/habitat-maintenance flow releases are releases at or near power plant capacity, which are intended to maintain favorable beach and habitat conditions for recreation and fish and wildlife, and to protect Tribal interests. Beach/habitat-maintenance flow releases can be made in years when no BHBF releases are made. Both beach/habitat-building and beach/habitat-maintenance flows, along with the testing and evaluation of other types of releases under the AMP, were recommended by the Service to verify a program of flows that would improve habitat conditions for endangered fish. The proposed interim surplus criteria could affect the range of storage conditions in Lake Powell and alter the flexibility to schedule and conduct such releases or to test other flow patterns. The magnitude of this reduction in flexibility has been COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-25 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 123 of 1200 CHAPTER 1 INTRODUCTION evaluated for each interim surplus alternative. The results are presented in Section 3.6, Riverflow Issues. 1.4.2.3 TEMPERATURE CONTROL AT GLEN CANYON DAM In 1994, the Service issued a Biological Opinion on the Operation of Glen Canyon Dam. One of the elements of the reasonable and prudent alternative in the Biological Opinion, also a common element in the Glen Canyon Dam EIS, was the evaluation of methods to control release temperatures and, if viable, implement controls. Reclamation agreed with this recommendation and included it in the Operation of Glen Canyon Dam Final Environmental Impact Statement and subsequent ROD. Reclamation has issued a draft planning report and environmental assessment (EA) entitled Glen Canyon Dam Modifications to Controls and Downstream Temperatures (Reclamation, 1999). Based on comments to this draft EA, Reclamation is currently in the process of preparing a new draft EA on temperature control at Glen Canyon Dam. Interim surplus criteria could result in new information related to temperature control at Glen Canyon Dam. Data and information made available from analysis related to interim surplus criteria will be utilized in the revised EA on temperaturercontrol at Glen rio Canyon Dam. Such information would also be considered in e Inte h the development of an t 017 appropriate design for a temperature control device.pt. of 29, 2 e .D ber ion v NovemAND CONFERENCE 1.4.3 ACTIONS RELATED jo Nat BIOLOGICAL a TO THE d on OPINION ONn Nav COLORADO RIVER OPERATIONS AND LOWER rchive i a cited 16 MAINTENANCE 864, 14No. a Biological Assessment (BA) in accordance with Section 7 of Reclamation prepared the ESA, addressing effects of ongoing and projected routine lower Colorado River operations and maintenance (Reclamation, 1996). After formal consultation, a Biological and Conference Opinion (BCO) was prepared by the Service (Service, 1997). Both documents are described in Section 1.4.5, Documents Incorporated by Reference. Pursuant to the reasonable and prudent alternative and 17 specific provisions provided in the BCO, Reclamation is taking various actions that benefit the riparian region of the lower Colorado River and associated species. In particular, these actions include: 1) acquisition, restoration, and protection of potential and occupied Southwestern willow flycatcher habitat; 2) extensive life history studies for Southwestern willow flycatcher along 400 miles of the lower Colorado River and other areas; and 3) protection and enhancement of endangered fish species through risk assessments, assisted rearing, and development of protected habitats along the lower Colorado River. This five-year BCO provides ESA compliance for Reclamation actions on the lower Colorado River until 2002. The BA and BCO contain life histories/status of lower Colorado River species, descriptions of ongoing and projected routine operation and maintenance activities, the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-26 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 124 of 1200 CHAPTER 1 INTRODUCTION Secretary’s discretionary management activities, operation and maintenance (O&M) procedures, endangered species conservation program, environmental baseline, effects of ongoing operations, reasonable and prudent alternatives, and supporting documentation useful in this FEIS. The 1996 BA and the 1997 BCO did not anticipate or address the effects of specific interim surplus criteria on the species considered. A separate Section 7 ESA consultation is in progress for the proposed action addressed by this FEIS. 1.4.4 LOWER COLORADO RIVER MULTI-SPECIES CONSERVATION PROGRAM Following the designation of critical habitat for three endangered fish species on nearly all of the lower Colorado River in April of 1994, the three Lower Basin States of Arizona, California and Nevada, Reclamation and the Service initiated the Lower Colorado River Multi-Species Conservation Program (LCRMSCP), which was one of the reasonable and prudent provisions of the five-year BCO received in 1997. The purpose of the LCRMSCP is to obtain long-term (50-year) ESA compliance for both federal and non-federal water and power interests. The LCRMSCP is a partnership of Federal, State, Tribal, and other public and private stakeholders with an interest in managing the water and related resources of the lower Colorado Riverior Basin. In August Inter 1entered into a e 1995, the Department of the Interior and Arizona, California and Nevada 7 of th 29, 20 Memorandum of Agreement (MOA) and later aDept. Memorandumrof Clarification (MOC) . mbe for development of the LCRMSCP. Theon v ati purpose ofoveMOA/MOC was to initiate N the development of an LCRMSCPajo N ved on av that would accomplish the following objectives: N rchi d in 6 itehabitat and4, a toward the recovery of threatened and endangered c • Conserve 4-168 work 1 specieso. reduce the likelihood of additional species listing under the ESA; N and and • Accommodate current water diversions and power production and optimize opportunities for future water and power development. The LCRMSCP is currently under development, and it is anticipated that the final EISenvironmental impact report (EIR) will be finalized in 2001. Once the LCRMSCP is accepted by the Service, Reclamation and other federal agencies, as well as the participating non-federal partners, will have achieved ESA compliance for ongoing and future actions. Since the interim surplus criteria determination is scheduled to be completed prior to the completion of the LCRMSCP, a separate Section 7 consultation has been conducted with the Service on the anticipated effects of implementing the interim surplus criteria. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-27 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 125 of 1200 CHAPTER 1 INTRODUCTION 1.4.5 SECRETARIAL IMPLEMENTATION AGREEMENT RELATED TO CALIFORNIA’S COLORADO RIVER WATER USE PLAN Within California, the allocation of Colorado River water is stipulated by various existing agreements among the seven parties with diversion rights. Recently, these parties have negotiated a Quantification Settlement Agreement which further defines the priorities for use of Colorado River water in California. This agreement provides a basis for various water conservation and transfer measures described in the CA Plan (California, 2000). The water transfers would require changes in the points at which the Secretary would deliver transferred water to various California entities, as compared with provisions in existing water delivery contracts. The operational changes caused by the water transfers are being addressed in separate NEPA and ESA documentation. 1.4.6 OFFSTREAM STORAGE OF COLORADO RIVER WATER AND DEVELOPMENT AND RELEASE OF INTENTIONALLY CREATED UNUSED APPORTIONMENT IN THE LOWER DIVISION STATES The above titled rule establishes a procedural framework for the Secretary to follow in rior considering, participating in, and administering Storage andhe Inte Release Interstate 17 t Agreements among the States of Arizona, California,tandfNevada 9, 20 Division p . o er 2 (Lower . De states). The Storage and Interstate Release Agreementsemb permit State-authorized ion v Nov would t N offstream, develop intentionally created unused entities to store Colorado River watera on vajoICUAvavailable to the Secretary for release for use in Namakearchi ed apportionment (ICUA), and d in , another Lower cite -16864 Division state. This rule provides a framework only and does not 14 authorize any specific activities. The rule does not affect any Colorado River water No. entitlement holder’s right to use its full water entitlement, and does not deal with intrastate storage and distribution of water. The rule only facilitates voluntary interstate water transactions that can help satisfy regional water demands by increasing the efficiency, flexibility, and certainty in Colorado River management. A Finding of No Significant Impact (FONSI) was approved on October 1, 1999. 1.5 DOCUMENTS INCORPORATED BY REFERENCE During recent decades, a considerable amount of environmental information has been obtained and environmental analyses conducted concerning the operation of the Colorado River water supply system. Much of this information is contained in various documents prepared under NEPA and the ESA. These documents have been previously distributed to interested agencies and private parties. In the interest of avoiding duplication and undue paperwork, this FEIS incorporates by reference parts or all of several documents. The documents described below are available for public inspection upon request at Reclamation offices in Boulder City, Nevada; Salt Lake City, Utah; Phoenix and Yuma, Arizona. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-28 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 126 of 1200 CHAPTER 1 INTRODUCTION • Biological Assessment for Proposed Interim Surplus Criteria, Secretarial Implementation Agreements for California Water Plan Components and Conservation Measures, August 30, 2000. This BA was prepared by Reclamation in Boulder City, Nevada, to address the potential effects on threatened or endangered species and designated critical habitat along the lower Colorado River attributable to the water transfers proposed by California as part of its CA Plan and to the implementation of the proposed interim surplus criteria. The BA was prepared to facilitate formal Section 7 consultation with the Service, which resulted in the BO cited below addressing these proposed actions. The pertinent parts of this BA are the ecology of aquatic and riparian habitat systems from Lake Mead to the SIB and the potential effects of these proposed actions on listed species and critical habitat. With regard to any potential effects of the proposed adoption of interim surplus criteria on ESA listed species in the Republic of Mexico or the Gulf of California, Reclamation has prepared additional information to supplement this assessment. • Biological Opinion on Proposed Interim Surplus Criteria, Secretarial Implementation Agreements for California Water Plan Components and r Conservation Measures, December, 2000. terio In f he 9 2017 . oin tPhoenix,, Arizona, through This Biological Opinion (BO), issued by theDept Service ber 2 mNevada, addresses the n v. formal consultation with Reclamation in Boulder City, atio Nove potential effects on threatened or endangered species and designated critical habitat ajo N ived on av along the lower d in N River rattributable to the water transfer agreements Colorado 4, a ch cite 16 as proposed by California 86part of its CA Plan and to the implementation of interim 14surplus criteria. The BO identifies reasonable and prudent measures for the No. avoidance of adverse effects of these proposed actions. The pertinent parts of the BO are the life histories of various species, their habitat descriptions, and relationships with river operations. • Biological Assessment on Transboundary Effects for Proposed Interim Surplus Criteria, December, 2000. This BA was prepared by Reclamation in Boulder City, Nevada, to address the potential effects on threatened or endangered species in the Colorado River Delta of Mexico attributable to the implementation of proposed interim surplus criteria. The BA was prepared to facilitate informal consultation with the Service and the National Marine Fisheries Service, which is in progress. The pertinent parts of the BA are the ecology of aquatic and riparian habitat systems from the SIB to the estuary at the mouth of the Colorado River in the Sea of Cortez and the potential effects of the proposed action on United States-listed species and critical habitat. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-29 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 127 of 1200 CHAPTER 1 INTRODUCTION • Description and Assessment of Operations, Maintenance, and Sensitive Species of the Lower Colorado River (Biological Assessment), August 1996. This BA was prepared by Reclamation in Boulder City, Nevada, to develop an inventory of aquatic and marsh habitat along the lower Colorado River and to analyze the relationships between river operation and maintenance of threatened and endangered species and critical habitat. The BA was prepared to facilitate the formal Section 7 consultation with the Service, which resulted in the April 1997 BCO cited below. The pertinent parts of the BA are the ecology of aquatic and riparian habitat systems from Lake Mead to the SIB and the potential effects of ongoing operation and maintenance on listed species and critical habitat. • Biological and Conference Opinion on Lower Colorado River Operations and Maintenance, April 1997. This BCO, prepared by the Service in Phoenix, Arizona, through formal consultation with Reclamation in Boulder City, Nevada, addresses the critical habitat for endangered species along the lower Colorado River that is related to the operation of the river for delivery of water to the Lower Division states and Mexico. The report identifies a reasonable and prudent alternative for the avoidance of or nteri 7 Iconference and opinion adverse effects of river operation. The pertinent partsfofhe the 201 o t are the life histories of various species, theirDept. descriptions, and relationships habitat r 29, be v. with river operations. ovem ation N N vajo hived on n Na , r • Operation of GleniCanyon Dam c 4 October 8, 1996. ited of Decision,a Final Environmental Impact Statement, March c 1995, and Record4-1686 1 No. The FEIS was prepared by Reclamation in Salt Lake City, Utah, to evaluate alternative plans for the water releases at Glen Canyon Dam and Powerplant and the ecological effects on the Colorado River corridor downstream to Separation Rapid. The FEIS was based on an extraordinary depth of analysis, involving numerous work groups with specialists in various disciplines from other agencies and private practice. The pertinent parts of the FEIS are the aquatic and riparian habitats below Glen Canyon Dam, the relationships between Glen Canyon Dam and Powerplant release patterns, effects on downstream ecology, and the sedimentation processes associated with the maintenance of backwaters and beaches along the river. The relationships between release patterns and the value of hydroelectric energy produced were also pertinent. The ROD adds commitments in the following areas: establishment of an AMP, monitoring and protecting cultural resources, flood frequency reduction measures, BHBF releases, efforts to establish a new population of the humpback chub, further study of selective withdrawals from Lake Powell, and emergency exception criteria to respond to various emergency situations. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-30 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 128 of 1200 CHAPTER 1 INTRODUCTION • Glen Canyon Dam Modification to Control Downstream Temperatures Plan and Environmental Assessment, January 1999 Draft. This draft planning report and EA was prepared by Reclamation in Salt Lake City, Utah, to consider alternatives for modifying the intakes to the penstocks to permit the selective withdrawal of water from Lake Powell at various temperatures. The pertinent parts of the report are the sensitivity of downstream fish species, particularly endangered species, to temperatures of Colorado River water downstream from the dam and the degree of temperature control that could be achieved by the modifications. Based on comments on the draft EA, Reclamation is in the process of preparing a new draft EA on temperature control at Glen Canyon Dam. • Final Biological Opinion, Operation of Glen Canyon Dam as the Modified Low Fluctuating Flow Alternative, December 1994. This Biological Opinion was prepared by the Service in Phoenix, Arizona, through consultation with Reclamation in Salt Lake City, Utah. The document addresses Glen Canyon Dam operations and the critical habitat for endangered species in the Colorado River from Glen Canyon Dam to Lake Mead and identifies a reasonable ior Inter 1also provides e and prudent alternative for the avoidance of jeopardy.f The document 7 20 o th area related to the environmental baseline and status of speciesDethe. actioner 29, in pt b v. preferred alternative. ovem ation N N vajo hived on in Na rc • Glen Canyon Adaptive Management Work Group Charter, December 8, 1998. ited 6864, a c -1 This charter outlines the membership and duties of the AMWG. The duties are to o. 14 N establish AMWG operating procedures, advise the Secretary in meeting environmental and cultural commitments of the Glen Canyon Dam FEIS and ROD, recommend a framework for AMP policy, goals and direction; develop recommendations for modifying dam operations and operating criteria; define and recommend resource management objectives for a long-term monitoring plan; review and provide input to the Secretary on required reports; facilitate input and coordination of information from stakeholders to the Secretary; and monitor and report on compliance of all program activities with applicable laws, permitting requirements, and the Grand Canyon Protection Act. • Quality of Water, Colorado River Basin, Progress Report No. 19, January 1999. This report is the latest of a series of biennial reports to Congress, prepared by Reclamation in Salt Lake City, Utah, that summarize progress of the Colorado River Water Quality Improvement Program in controlling Colorado River salinity. The pertinent parts of the report are those which discuss the mechanisms that contribute dissolved salts to the river system, the relationships between dissolved salt COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-31 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 129 of 1200 CHAPTER 1 INTRODUCTION concentrations and abundance of basin water supply, and the effects of dissolved minerals on uses of Colorado River water. • Southern Nevada Water Authority Treatment and Transmission Facility Final Environmental Impact Statement, September 1996, and Record of Decision, November 1996. This EIS and ROD contain pertinent information concerning the influence of Las Vegas Valley drainage on the water quality in Lake Mead’s Boulder Basin and the resulting quality of water pumped from the reservoir by the SNWA’s intake facilities. Critical intake elevations are identified in the documents. • Final Programmatic Environmental Assessment for Rulemaking for Offstream Storage of Colorado River Water and Development and Release of Intentionally Created Unused Apportionment in the Lower Division States, October 1999. This document, which includes a BA, analyzes the environmental effects of potential changes in reservoir and river operations that could occur if a Lower Division state diverts and stores water for the benefit of another Lower Division state for future use (interstate offstream storage). The BA containsor aquatic and eri marsh habitat descriptions and the relationships betweenhe Int in diversions from changes 17 0 f t marsh habitat Lake Mead and Lake Havasu and downstreamept. o and r 29, 2 aquatic D mbe maintenance. The relationships between v. n release patterns from atiouseful for oveanalysis. Hoover Dam and the N this value of hydroelectric energyo Nalso ed on vaj are in Na rchiv ited 6864, a c -1 o. 14 N COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1-32 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 130 of 1200 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 131 of 1200 2 DESCRIPTION OF ALTERNATIVES 2.1 INTRODUCTION This chapter discusses the process used to define the No Action Alternative and develop a range of reasonable interim surplus criteria alternatives, and summarizes various alternatives that were considered but eliminated from further analysis. It then describes the alternatives analyzed in this FEIS. Modeling procedures and assumptions used to analyze the alternatives are discussed in Section 3.3. The end of this chapter presents a table of effects of all alternatives. 2.2 DEVELOPMENT OF ALTERNATIVES This FEIS considers five interim surplus criteria alternatives as well as a No Action Alternative/baseline that was developed for comparison of potential effects. The five action alternatives considered include the Basin States Alternative (preferred alternative), the Flood Control Alternative, the Six States Alternative, the California Alternative, and the Shortage Protection Alternative (as described in Section 2.3). ior Section 2.2.1 discusses the strategies and origins of the action alternatives and describes Inter 17 f the 9, 2 alternatives that were considered but eliminated fromtfurther analysis. 0 p.o . De e er 2 n vSURPLUSmb a FOR 2.2.1 OPERATING STRATEGIEStio Nov DETERMINATION ajo N ived on Nav d in 64, arch 2.2.1.1 THE R STRATEGY cite 168 14No. In 1986, Reclamation developed an operating strategy for distributing surplus water and avoiding spills (Reclamation, 1986). That analysis established the Spill Avoidance or “R” strategy. The development of this strategy was an outcome of sustained flood control releases at Lake Mead from 1983 through 1986. The R strategy assumes a particular percentile historical runoff, along with normal 7.5 maf delivery to Lower Division states, for the next year. Applying these values to current reservoir storage, the projected reservoir storage at the end of the next year is calculated. If the calculated space available at the end of the next year is less than the space required by flood control criteria, then a surplus condition is determined to exist. Two alternatives considered in this FEIS use variations of the R strategy. The 70R strategy uses an annual runoff of 17.4 maf whereas the 75R strategy uses 18.1 maf. The 70R strategy was used to represent the baseline as described in Section 2.3.1. 2.2.1.2 THE A STRATEGY In the early and mid-1990s, Reclamation continued discussing surplus criteria strategies with the Colorado River Management Work Group (CRMWG), which formed a technical committee was formed to investigate additional surplus criteria strategies. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 132 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 One of the strategies developed through the CRMWG analysis was the Flood Control avoidance or “A” strategy. This strategy determines when there is insufficient storage space in Lake Mead and upstream reservoirs, in order to avoid flood control releases from Lake Mead with a particular percent assurance. The most common usage became the 70 percent assurance level (70A strategy). This alternative was eliminated because the modeling results were so similar to the Flood Control Alternative and the No Action/baseline (70R strategy) that it was not necessary to analyze it. 2.2.1.3 THE P STRATEGY Another strategy is the Shortage Protection or “P” strategy. This strategy is based on making surplus water available while maintaining storage sufficient to meet a 7.5 maf Lake Mead release requirement, while avoiding the likelihood of a future shortage determination at a specified assurance level. Through a separate modeling study, Reclamation determined the Lake Mead storage needed in each future year to meet Lower Basin and Mexico demands, with a specified percent assurance that Lake Mead would not drop below a specified elevation. Water stored in Lake Mead in excess of that storage requirement is deemed surplus to be made available to theior Lower Basin Inter 17 states. The Shortage Protection Alternative used in this FEIS, commonly referred to as 0 f the the 80P strategy, is described in more detail in Section. 2.3.6. r 29, 2 pt o e v. D mbe ation on Nove 2.2.1.4 FLOOD CONTROL STRATEGY jo N Nava archived in cited 1686 surplus conditions are determined only when flood Under a flood control strategy,4, 1 control releases from 4 No. Lake Mead are occurring or projected to occur in the subsequent year. In the 1998, 1999 and 2000 Annual Operating Plans (AOPs), Reclamation used the projection of flood control releases as the basis for making surplus water available to the Lower Division States. The Flood Control Alternative in this FEIS uses this strategy and is described in Section 2.3.3. 2.2.2 ORIGINS OF THE CALIFORNIA, SIX STATES, AND BASIN STATES ALTERNATIVES On December 17, 1997, California presented to the other Basin States its draft 4.4 Plan (CRBC, 1997), a plan to achieve a reduction in its dependence on surplus water from the Colorado River, through various conservation measures, water exchanges and conjunctive use programs. One of the elements of the draft 4.4 Plan was the expectation that the Secretary would continue to determine surplus conditions on the Colorado River until 2015. California proposed criteria on which the Secretary would base his determinations of surplus conditions during the interim period. In 1998, in response to California’s 1997 proposal of interim surplus criteria, the other six states within the Colorado River Basin (Six States) submitted a proposal with COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 133 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 surplus criteria that were similar in structure to those in California’s proposal. Under the proposal from the Six States, use of surplus water supplies would be limited depending on the occurrence of various specified Lake Mead surface elevations. The interim surplus criteria proposed by the Six States, presented in Attachment E, were used to formulate the “Six States Alternative” presented in Section 2.3.4. California subsequently proposed specific interim surplus criteria which were attached to the October 15, 1999 Key Terms for Quantification Settlement Among the State of California, Imperial Irrigation District, Coachella Valley Water District, and Metropolitan Water District of Southern California (See Attachment F). California also updated, renamed and re-released its 4.4 Plan in May 2000. The revised plan is now known as the California Colorado River Water Use Plan (CA Plan). The interim surplus criteria proposal stemming from the CA Plan and Quantification Settlement was used to formulate the “California Alternative” detailed in Section 2.3.5. In July 2000, during the public comment period on the DEIS, Reclamation received a draft proposal for interim surplus criteria from the seven Colorado River Basin States (Seven States). After a preliminary review of that proposal, Reclamation published it in the August 8, 2000 Federal Register for review and consideration by the public during the public review period for the DEIS. Reclamation published minorrior corrections to the Inte of 17 Federal proposal in a Federal Register notice of September 22, 2000. e Copies the of th 29, 20 Register notices are in Chapter 5. Reclamation Dept. the Basin States Alternative in derived . ber this FEIS from the draft Seven States ation v Proposal. vem o N N vajo hived on a 2.2.3 PACIFIC ed in N INSTITUTE,PROPOSAL arc it c 864 -16 On February 15,o. 14 a consortium of environmental organizations led by the Pacific 2000, N Institute for Studies in Development, Environment and Security (Pacific Institute) presented an interim surplus criteria proposal for consideration by the Secretary. Their proposal (as clarified by the Pacific Institute’s September 8, 2000 letter of comment on the DEIS), contains interim surplus criteria that are similar to the criteria in the Six States Alternative with respect to Lower Basin surplus determinations. The proposal and excerpts from the September 8 letter are included as Attachment G to this FEIS. The Pacific Institute Proposal also suggested that, during years when Lake Mead’s surface elevation exceeds 1120.4 feet mean sea level (msl), at least 32,000 af of additional water (i.e. water in excess of Mexico's treaty deliveries) be delivered to Mexico for the purpose of restoring and/or maintaining habitat in the upper reaches of the Colorado River delta. The proposal also included 260,000 af of additional water to be delivered to the Colorado River delta for ecological restoration purposes when reservoir elevations are high. This proposal is beyond the purpose and need for the proposed action because it would expand the proposed action by prescribing releases of Colorado River water stored in Lake Mead to Mexico. The proposed adoption of surplus criteria for use in Arizona, California and Nevada does not, by definition, apply to determinations of surplus to the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 134 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 United Mexican States (Mexico). Water delivery to Mexico is governed by the United States-Mexico Water Treaty of 1944. Releases of water to Mexico are not addressed by Section III(3) of the LROC or Article II(B)(2) of the Decree and are therefore not part of the proposed action analyzed in this EIS. From its initiation of this proposed action on May 18, 1999, Reclamation has clearly stated that its undertaking was intended to “identify those circumstances under which the Secretary of the Interior (“Secretary”) may make Colorado River water available for delivery to the States of Arizona, California, and Nevada .…” (64 Federal Register 27008, May 18, 1999). The proposed action only involves determinations of domestic surplus conditions pursuant to Article III(3) of the LROC (64 Federal Register 27009). Section 1.1.4 of the DEIS (page 1-4) states that “This proposed action is not intended to identify conditions when Mexico may schedule [its] 0.2 maf [surplus under Article 10(b) of the Treaty].” The United States, in its consultation with Mexico conducted through the Department of State, has consistently informed Mexico that the proposed action does not address determinations of surplus conditions to Mexico under the 1944 Treaty, and is limited to declarations of surplus conditions for the Lower Division states. In addition to changing and expanding the proposed action in a manner inconsistent with the purpose and need for the action, the Pacific Institute’s proposed alternative would also require that Reclamation make releases of water from Lakeor nteri Mead to Mexico in a manner that is inconsistent with the mandatory injunctione I the h issued to017Secretary by ft pt. o erCalifornia Decree 29, 2 the United States Supreme Court in Article II ofDe Arizona v. . the b i for v Nov water (1964). Pacific Institute’s proposal callson releases ofem from Lake Mead in at N on excess of the amount of water ajo would edreleased to Mexico “in satisfaction of [the Navthatarchivbe United States] obligations to 64,United States of Mexico under the treaty dated ed in 8 the cit.…” Reclamation does not believe that the range of reasonable February 3, 1944 14-16 No. alternatives includes alternatives that would violate the United States Supreme Court’s Decree and injunction. For the foregoing reasons, Reclamation concluded that the proposed alternative was not a reasonable alternative and it accordingly was not analyzed in this EIS. Because the Lower Basin surplus determinations of the Pacific Institute’s proposed interim surplus criteria are similar to, and within the range of, those contained in the alternatives already being analyzed, and because the proposed delivery of additional water to Mexico is beyond the purpose and need for interim surplus criteria, the Pacific Institute’s proposal is not analyzed in this FEIS. 2.2.4 FORMULATION OF ALTERNATIVES In response to the CA Plan and the Six States proposal, and the dialogue among Reclamation and the seven Basin States, Reclamation initiated a NEPA process to provide structure to evaluating potential interim surplus criteria alternatives and to determine and disclose the potential effects of these interim surplus criteria. At the initiation of the NEPA process, Reclamation began a public scoping process. Under that process, Reclamation conducted a series of public meetings in 1999 to inform COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 135 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 interested parties of the consideration being given to the development of interim surplus criteria, to show options and proposals developed up to that time, and to solicit public and agency comments and suggestions regarding the formulation and evaluation of alternatives for the criteria. The alternatives below were presented at the public meetings: Flood Control Alternative Spill Avoidance Alternative (70R) Flood Control Avoidance Alternative (70A) Multi-tier Alternative (based on the Six States Plan) Shortage Protection Alternative (80P) The scoping process and issues identified, including those associated with alternatives development, are discussed in Chapter 5 of this FEIS. Following the scoping meetings, and in consideration of comments received, Reclamation included the interim surplus criteria proposals of the Six States and California for evaluation in the DEIS. It should be noted that while the California and Six States alternatives analyzed in the DEIS and in this FEIS were based on criteria proposed by California and the Six States, the respective alternatives presented in this FEIS do not contain all the specific elements of ior Inter 17 those plans. the 20 of ept. ber 29, D The draft Seven States proposal was discussed. informally with the public during the m ion v atwas the n Nove comment in various letters public review period for the DEIS, N and subject of vajo h ved o received by Reclamation Na in in responsecto ithe DEIS and the Federal Register notice of the , ar c ond 1 discussions and comments, Reclamation formulated an proposal. Basedite these 6864 alternative basedo. 14 Seven States proposal and identified it as the preferred N on the alternative (the Basin States Alternative herein). It should be noted that the Basin States Alternative presented in this FEIS does not contain all the specific elements of the draft Seven States proposal. 2.2.5 UTILIZATION OF PROPOSALS FROM THE BASIN STATES As discussed in Section 2.2.2, various proposals submitted by individual Colorado River Basin states or groups of states were used by Reclamation to formulate interim surplus criteria alternatives. In recognition of the need to limit the delivery of surplus water at lower Lake Mead water levels, these proposals specified allowable uses of surplus water at various triggering levels. The Secretary will continue to apportion surplus water consistent with the applicable provisions of the Decree, under which surplus water is divided 50 percent to California, 46 percent to Arizona, and 4 percent to Nevada. The Secretary also intends to appropriately report the accumulated volume of water delivered to MWD under surplus conditions. The Secretary also intends to honor any forbearance arrangements made by COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 136 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 various parties for the delivery of surplus water or reparations for future shortage conditions. 2.2.6 NO ACTION ALTERNATIVE AND BASELINE CONDITION As required by NEPA, a No Action alternative must be considered during the environmental review process. Under the No Action Alternative, determinations of surplus would continue to be made on an annual basis, in the AOP, pursuant to the LROC and the Decree as discussed in Chapter 1. The No Action Alternative represents the future AOP process without interim surplus criteria. Surplus determinations consider such factors as end-of-year system storage, potential runoff conditions, projected water demands of the Basin States and the Secretary’s discretion in addressing year-to-year issues. However, the year-to-year variation in the conditions considered by the Secretary in making surplus water determinations makes projections of surplus water availability highly uncertain. The approach used in this FEIS for analyzing the hydrologic aspects of the interim surplus criteria alternatives was to use a computer model that simulates specific operating parameters and constraints. In order to follow CEQ guidelines calling for a No Action alternative for use as a “baseline” against which to compareor i project In er a baseline alternatives, Reclamation selected a specific operating strategy fortuse as17 0 f the condition, which could be described mathematically in the model. 9, 2 pt. o e r2 v. D v mbe o ation ostrategy.e Reclamation has utilized a 70R The baseline is based on a 70Rajo N avoidance N v spill andived n surplus determinations in past years. strategy for both planning purposesrch studies of in Na ited 6864, a surplus determinations as part of the DEIS effort, c When Reclamation reviewed previous -1 the data indicated . 14the 1997 surplus determination did not precisely fit the 70R o that N strategy. As a result, Reclamation selected the 75R strategy as representative of recent operational decisions, for use as the baseline condition in the DEIS. However, based on further review and analysis, public comment, and discussion with representatives of the states during the DEIS review period, Reclamation is using the 70R strategy for the baseline condition in this FEIS. While the 70R strategy is used to represent baseline conditions, it does not represent a decision by Reclamation to utilize the 70R strategy for determination of future surplus conditions in the absence of interim surplus criteria. It should be noted that the 70R strategy and 75R strategy yield very similar results for the purpose of determining impacts associated with the action alternatives analyzed in this FEIS. Figure 2-1 illustrates the close relationship between the 70R and 75R trigger lines (see Section 2.3.1.2). 2.3 DESCRIPTION OF ALTERNATIVES This section describes the five interim surplus criteria alternatives analyzed in this FEIS, and No Action, which is represented by the baseline condition for comparison purposes. The Secretary would base his annual determination of surplus conditions on the criteria selected, if any, as part of the AOP process unless extraordinary COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 137 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 circumstances arise. Such circumstances could include operations necessary for safety of dams or other emergency situations, the failure of California to meet its commitment to reduce dependence on Colorado River water, or other activities arising from actual operating experiences. The interim surplus criteria would remain in effect for surplus determinations made through calendar year 2015, subject to five-year reviews concurrent with the LROC reviews. As noted in Section 1.4.1, implementation of interim surplus criteria would take into account the progress, or lack thereof, in the implementation of the CA Plan. As noted above, the 70R operating strategy is not presented as an alternative for adoption. If an interim surplus criteria alternative is not implemented, the Secretary would determine surplus conditions using the same dynamic considerations currently used in the AOP. Subsequent to the surplus determination for 2016, the interim surplus criteria would terminate and, in the absence of subsequently-specified surplus criteria, surplus determinations would be made by future Secretaries based on factors such as those that are considered in the AOP, as discussed in Chapter 1. Because the selected baseline and the interim surplus criteria alternatives deal with ior Inter 17 operations, rather than construction or other physical Colorado River system changes, 0 f the the alternatives are described below in terms of their operatingrrules. 2 Department pt. o e 29, The e D mb and Reclamation intend to deliver waterion v. Article II(B)2 of the at in accordance withto be available each year Nove N n projected o o Decree. The estimated volumesjof surplus water ava ved under baseline conditionsN each rchi in and 4, a alternative are tabulated to demonstrate the cited 1686 operation under the respective conditions. The projected volumes of surplus water vary 4over the interim o. 1 in response to various factors including the implementation of N period various components of the CA Plan. A common element of all alternatives is that in years in which the Field Working Agreement between the Bureau of Reclamation and the Army Corps of Engineers for Flood Control Operation of Hoover Dam and Lake Mead requires releases greater than the downstream beneficial consumptive use demands, the Secretary shall determine a “flood control surplus” will be declared in that year. In such years, releases will be made to satisfy all beneficial uses within the United States (see the estimated amounts under Flood Control for each alternative), and up to an additional 200,000 af will be made available to Mexico under the Treaty. 2.3.1 NO ACTION ALTERNATIVE AND BASELINE CONDITION 2.3.1.1 APPROACH TO SURPLUS WATER DETERMINATION As discussed above in Section 2.2.6, the 70R operating strategy is being used as a baseline to show possible future operating conditions in the absence of interim surplus criteria. The primary effect of simulating operation with the 70R operating strategy COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 138 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 would be that surplus conditions would only be determined when Lake Mead is nearly full. 2.3.1.2 70R BASELINE SURPLUS TRIGGERS The 70R baseline strategy involves assuming a 70-percentile inflow into the system subtracting out the consumptive uses and system losses and checking the results to see if all of the water could be stored or if flood control releases would be required. If flood control releases would be required, additional water is made available to the Lower Basin states beyond 7.5 maf. The notation 70R refers to the specific inflow where 70 percent of the historical natural runoff is less than this value (17.4 maf) for the Colorado River basin at Lee Ferry. The 70R strategy is illustrated on Figure 2-1, which shows the average trigger elevation of Lake Mead’s water surface above which a surplus would be determined. In practice, the 70R surplus determination would not be based on the trigger line shown, but would be made during the fall of the preceding year using projected available system space. The 70R trigger line rises from approximately 1199 feet msl in 2002 to 1205 feet msl in 2050. The gradual rise of the 70R trigger line shown in Figure 2-1 is the result of ior Inter 1 a increasing water use in the Upper Basin. Under baseline conditions, when7 surplus the 0 condition is determined to occur, surplus water would .be f pt o maderavailable to fill all water 29, 2 e v D orders by holders of surplus water contracts in.the Lowermbe Division states in estimated ation on Nove N amounts on Table 2-1. ajo d ive Nav d in 64, arch cite 168 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-8 1,000 2000 1,050 1,100 1,150 1,200 1,250 2005 2010 2015 2020 2-9 Year 2025 2030 2035 2040 M INIM UM NEVADA PUM PING ELEVATIO N=1000 FT 75R TRIGGER FOR COMPARISON SPILLW AY ELEVATION=1221 FT ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in M64UMarc cite 168 INIM , ELEVATION FO R POW ER GENERATION=1083 FT o. 14 N 70R AVERAGE TRIGGER AVERAGE FLOOD RELEASE TRIGGER Figure 2-1 Baseline Surplus Trigger Elevations COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Lake Mead Elevation (feet) DESCRIPTION OF ALTERNATIVES 2045 2050 CHAPTER 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 139 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 140 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 Table 2-1 Baseline Potential Surplus Water Supply Unit : thousand acre-feet (kaf) Year 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2.3.2 Flood Control 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 70R Trigger 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 BASIN STATES ALTERNATIVE (PREFERRED ALTERNATIVE) Reclamation has identified the Basin States Alternative as the preferred alternative in rior this FEIS. The Basin States Alternatives is similar to, and based nte information I upon, 17 the the 20 submitted to the Secretary by representatives of the pt. of governors of29, states of Colorado, e r Wyoming, Utah, New Mexico, Arizona,ion v. D California. After receipt of this Nevada and vembe t No information (during the public ajo Na period), Reclamation shared the submission v commentved on Reclamation’s surplus criteria web with the public (through the Federalchi in Na r Register and ited and 864, a Reclamation then analyzed the states’ c sites) for consideration 16 comment. 14submission and crafted this additional alternative for inclusion in the FEIS. Some of the No. information submitted for the Department’s review was outside of the scope of the proposed action for adoption of interim surplus criteria and was therefore not included as part of the Basin States Alternative (i.e., adoption of shortage criteria and adoption of surplus criteria beyond the 15-year period) as presented in this FEIS. With respect to the information within the scope of the proposed action, Reclamation found the Basin States Alternative to be a reasonable alternative and fully analyzed all environmental effects of this alternative in this FEIS. The identified environmental effects of the Basin States Alternative are well within the range of anticipated effects of the alternatives presented in the DEIS and do not affect the environment in a manner not already considered in the DEIS. Reclamation selected the Basin States Alternative as its preferred alternative based on Reclamation's determination that it best meets all aspects of the purpose and need for the action, including the needs to remain in place for the entire period of the interim criteria, to garner support among the Basin States that will enhance the Secretary’s ability to manage the Colorado River reservoirs in a manner that balances all existing needs for these precious water supplies, and to assist in the Secretary’s efforts to insure that California water users reduce their over reliance on surplus Colorado River water. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 141 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 Reclamation notes the important role of the Basin States in the statutory framework for administration of Colorado River Basin entitlements and the significance that a sevenstate consensus represents on this issue. Thus, based on all available information, this alternative appears to be the most reasonable and feasible alternative. 2.3.2.1 APPROACH TO SURPLUS WATER DETERMINATION The Basin States Alternative specifies ranges of Lake Mead water surface elevations to be used through 2015 for determining the availability of surplus water through 2016. The elevation ranges are coupled with specific uses of surplus water in such a way that, if Lake Mead’s surface elevation were to decline, the amount of surplus water would be reduced. The interim criteria would be reviewed at five-year intervals with the LROC (and additionally as needed) and revised as needed based upon actual operational experience. 2.3.2.2 BASIN STATES ALTERNATIVE SURPLUS TRIGGERS The surplus determination elevations under the preferred alternative consist of the tiered Lake Mead water surface elevations listed below, each of which is associated with certain stipulations on the purposes for which surplus water could be used. The rior elevation tiers (also referred to as levels) are shown on Figuree Inte 2-2. They are as follows, 017 f th proceeding from higher to lower water levels: pt. o 29, 2 e .D ber v feet ion v to 1201 em msl) Nat Tier 1 - 70R Line (approximately 1199 n No vajo hived o Tier 2 - 1145 feet Na in msl rc itedfeet 6864, a Tier 3 -c 1125 msl -1 o. 14 N Table 2-2 lists the estimated maximum annual amounts of surplus water that would be available to contractors for surplus water in the Lower Division states under the Basin States Alternative, when Lake Mead is at or above each trigger. The table also lists the estimated amounts of surplus water that would be available to the Lower Division states when flood control releases are required. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-11 2000 1,000 1,050 1,100 1,150 1,200 1,250 70R AVERAGE TRIGGER SPILLW AY ELEVATION=1221 FT 2005 2010 2015 2020 2-12 Year 2025 2030 2035 M INIM UM NEVADA PUM PING ELEVATIO N=1000 FT 2040 ior Inter 17 TIER 2=1145 e of th 29, 20 pt. TIER 3=1125 . De ember v ation on Nov N vajo hived Na d in 64,Marc ELEVATION FO R POW ER GENERATION=1083 FT INIM UM cite 168 14 No. TIER 1=(70R) AVERAGE FLOOD RELEASE TRIGGER Figure 2-2 Basin States Alternative Surplus Trigger Elevations COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Lake Mead Elevation (feet) DESCRIPTION OF ALTERNATIVES 2045 2050 CHAPTER 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 142 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 143 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 Table 2-2 Basin States Alternative Potential Surplus Water Supply Unit: thousand acre-feet (kaf) Year 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Flood Control 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 Tier 1 (70R) 1150 1150 1050 1050 1050 1050 1100 1100 1150 1150 1200 1200 1200 1200 1200 Tier 2 (1145 feet) 650 600 550 550 500 500 450 450 450 450 450 450 450 450 450 Tier 3 (1125 feet) 200 200 150 150 150 150 150 150 150 200 200 250 250 300 300 The surplus amounts quantified for each tier in Table 2-2 are estimated annual ior quantities of water and are the Secretary’s best estimate of the amounts of surplus water Inter 17 th interim surplus guidelines. that could be made available during the 15-year period offthe e 0 pt. o er 29, 2 projected e These estimates are based on the most current .available data regarding v D mb Colorado River water use demands Naexisting contractors. The methodology that was by tion n Nove o that d o used to prepare the demandavaj scheduleshiveunderlie the surplus tables in this section is c in Nof “domestic,” “Direct Delivery Domestic Use” and “Offbased upon thecited definitions 864, ar 6 Stream Banking,” .as used in the information submitted to the Secretary by the Colorado 14-1 o (65 Federal Register 48531, 48535 [Aug. 8, 2000]). The quantities N River Basin states in each Tier are developed by using these definitions as set forth in the Basin States submission (see Table 2-2). Under these definitions, the quantity of estimated surplus quantities is based, in part, on supplying particular types of uses within the Lower Division states, with a higher priority for supplying domestic uses than that for irrigation uses or groundwater banking activities to supply future uses. While the Secretary, as an initial matter, would make surplus water available in amounts consistent with the percentages identified in Article II(B)(2) of the Decree, it is expected that water orders from Colorado River contractors will be submitted to reflect forbearance arrangements made by Lower Division states and individual contractors. The Secretary will deliver water to contractors in a manner consistent with these arrangements, to the extent that the water orders from contractors reflect these arrangements. The Secretary expects to make the specified quantities of water available during the 15-year period. However, the precise annual surplus quantities will continue to be reviewed on an annual basis during the preparation of the AOP, as required by applicable federal law, based on actual operating experience and updated information on the demand for Colorado River water by Lower Division contractors. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 144 of 1200 DESCRIPTION OF ALTERNATIVES 2.3.2.1.1 CHAPTER 2 Basin States Alternative Tier 1 (70R) The Basin States Alternative Tier 1 Lake Mead surplus trigger elevations are based on the 70R strategy and range from approximately 1199 feet msl to 1201 feet msl. In years when the Secretary determines that water should be released for beneficial consumptive use to reduce the risk of potential flood control releases based on the 70R operating strategy, the Secretary would determine the quantity of surplus water available and allocate it as follows: 50 percent to California, 46 percent to Arizona and 4 percent to Nevada. Regardless of the quantity of surplus water determined under Tier 1, surplus deliveries under Tier 2 (discussed below) would be met. 2.3.2.1.2 Basin States Alternative Tier 2 (1145 feet msl) The Basin States Alternative Tier 2 Lake Mead surplus trigger elevation is 1145 feet msl. At or above this Tier 2 elevation (and below the Tier 1 elevation), surplus water would be available for use by the Lower Division states in the estimated amounts in Table 2-2. ior Inter 17 f the 9, 20 pt. o erelevation is 1125 feet 2 The Basin States Alternative Tier 3 Lake Mead De trigger n v. surplus emb msl. At or above this Tier 3 elevation (and below Nov 2 elevation), surplus water the Tier Natio ajoLowerved on states in the estimated amounts on vthe would be available forin Nby use a rchi Division ite Mead6864,below the Tier 3 trigger surplus water would not be Table 2-2. At Laked levels a c made available. o. 14-1 N 2.3.2.1.3 Basin States Alternative Tier 3 (1125 feet msl) 2.3.2.2 DRAFT GUIDELINES Draft guidelines for implementation of the Basin States Alternative are presented in Attachment I. These guidelines describe in more detail the relationships between the implementation of interim surplus criteria under this alternative and the AOP process through which the Secretary would determine whether surplus water is available and how much is available. 2.3.3 FLOOD CONTROL ALTERNATIVE 2.3.3.1 APPROACH TO SURPLUS WATER DETERMINATION Under the Flood Control Alternative, a surplus condition is determined to exist when flood control releases from Lake Mead are occurring or projected to occur in the subsequent year. The method of determining need for flood control releases is based on flood control regulations published by the Los Angeles District of the Corps and the Field Working Agreement between the Corps and Reclamation, which are discussed in Section 1.3.6, Flood Control Operation. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-14 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 145 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 2.3.3.2 FLOOD CONTROL ALTERNATIVE SURPLUS TRIGGERS Under the flood control strategy, a surplus is determined when the Corps flood control regulations require releases from Lake Mead in excess of downstream demand. The specific operating provisions are described in Section 1.3.6, Flood Control Operation. If flood control releases are required, surplus conditions are determined to be in effect. This strategy is illustrated on Figure 2-3, which shows the average Lake Mead water surface elevation that would trigger flood control releases. The average triggering elevation is a level line at approximately 1211 feet msl. In practice, flood control releases are not based on the average trigger line shown, but would be determined each month by following the Corps regulations. The graph is a visual representation to illustrate the differences between the alternatives. When a flood control surplus is determined, surplus water would be made available for all established uses by contractors for surplus water in the Lower Division states. Table 2-3 lists the annual amounts of surplus water estimated to be available under the Flood Control Alternative. Table 2-3 Flood Control Alternative Potential Surplus Water Supply Unit: thousand acre-feet (kaf) ior Inter 17 Year 0 f the pt. o er 29, 2 e 2002 .D mb 2003 tion v a Nove N on jo2004 2005 Nava archived in cited 16864, 2006 2007 2008 o. 14 N 2009 Flood Control 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 2010 2011 2012 2013 2014 2015 2016 2.3.4 SIX STATES ALTERNATIVE 2.3.4.1 APPROACH TO SURPLUS WATER DETERMINATION The Six States Alternative specifies ranges of Lake Mead water surface elevations to be used through 2015 for determining the availability of surplus water through 2016. The elevation ranges are coupled with specific uses of surplus water in such a way that, if Lake Mead’s surface elevation were to decline, the amount of surplus water would be reduced. The interim criteria would be reviewed at five-year intervals with the LROC and as needed based upon actual operational experience. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-15 1,000 2000 1,050 1,100 1,150 1,200 1,250 2005 2010 2015 2020 2-16 Year 2025 2030 2035 M INIM UM NEVADA PUM PING ELEVATIO N=1000 FT 2040 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 M INIM UM ELEVATION FO R POW ER GENERATION=1083 FT o. 14 N AVERAGE FLOOD RELEASE TRIGGER SPILLW AY ELEVATION=1221 FT Figure 2-3 Flood Control Alternative Surplus Trigger Elevations COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Lake Mead Elevation (feet) DESCRIPTION OF ALTERNATIVES 2045 2050 CHAPTER 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 146 of 1200 7 0 R A V E R A G E T R IG G E R SPILLW AY ELEVATION=1221 FT 2005 T IE R 2 = 1 1 4 5 2010 2015 2020 2-17 Year 2025 2030 2035 2040 ior Inter 17 e of th 29, 20 pt. T IE R 3 = 1 1 2 5 . De ember v ation on Nov N vajo hived Na d in 64,Marc ELEVATION FO R POW ER GENERATION=1083 FT INIM UM cite 168 41 No. T IE R 1 = ( 7 0 R ) COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2000 1,000 1,050 1,100 1,150 1,200 AVERAGE FLOOD RELEASE TRIGGER Figure 2-4 Six States Alternative Surplus Trigger Elevations M 1,250 DESCRIPTION OF ALTERNATIVES 2045 2050 CHAPTER 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 147 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 148 of 1200 DESCRIPTION OF ALTERNATIVES CHAPTER 2 2.3.4.2 SIX STATES ALTERNATIVE SURPLUS TRIGGERS The surplus determination elevations under the Six States Alternative consist of the tiered Lake Mead water surface elevations listed below, each of which is associated with certain stipulations on the purposes for which surplus water could be used. The tiered elevations are shown on Figure 2-4. They are as follows, proceeding from higher to lower water levels: Tier 1 - 70R Line (approximately 1199 to 1201 feet msl) Tier 2 - 1145 feet msl Tier 3 - 1125 feet msl The following sections describe the various tiers and the estimated amounts of surplus water available at those tiers under the Six States Alternative. When flood control releases are made, any and all beneficial uses would be met, including unlimited off-stream storage. 2.3.4.2.1 Six States Alternative Tier 1 (70R) Six States Alternative Tier 1 Lake Mead surplus trigger elevations areior er based on the 70R strategy and range from approximately 1199 feet msl to 1201 e Inmsl during the feet t 017 f th interim period. When Lake Mead surface elevations t. oat or above, the 70R line (and pare 29 2 . De ber below the average flood release trigger tline shown in Figure 2.4), surplus water would ion v Novem Na be available. Table 2-4 lists the jestimateded on amounts of surplus water that would va o hiv annual a be available to the LowerN in Division states under the Basin States Alternative, when Lake rc ited Tier 1 4, a The table also lists the estimated amounts of c the 1686 trigger. Mead is at or above 14 surplus water that .would be available to the Lower Division states when flood control No releases are required. Table 2-4 Six States Alternative Potential Surplus Water Supply Unit: thousand acre-feet (kaf) Year 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Flood Control 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 Tier 1 Tier 2 Tier 3 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 600 550 500 500 450 450 450 400 400 400 400 400 400 400 400 350 300 250 250 200 200 150 150 150 150 150 150 150 150 150 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-18 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 149 of 1200 DESCRIPTION OF ALTERNATIVES 2.3.4.2.2 CHAPTER 2 Six States Alternative Tier 2 (1145 feet msl) The Six States Alternative Tier 2 Lake Mead surplus trigger elevation is 1145 feet msl. At or above this Tier 2 elevation (and below the Tier 1 elevation), surplus water would be available for use by the Lower Division states in the estimated amounts on Table 2-4. 2.3.4.2.3 Six States Alternative Tier 3 The Six States Alternative Tier 3 Lake Mead surplus trigger elevation is 1125 feet msl. At or above this Tier 3 elevation (and below the Tier 2 elevation). Surplus water would be available for use by the Lower Division states in the estimated amounts on Table 2-4. When Lake Mead water levels are below the Tier 3 trigger elevation, surplus water would not be available. 2.3.5 CALIFORNIA ALTERNATIVE 2.3.5.1 APPROACH TO SURPLUS WATER DETERMINATION The California Alternative specifies Lake Mead water surface elevations to be used for or the interim period through 2015 for determining the availability Ioftsurplus water n eri 7 through 2016. The elevation ranges are coupled with specifice surplus f th uses of201 water in pt. o theramount of surplus water 29, e such a way that, if Lake Mead’s surface elevation declines, be v. D m would be reduced. ation n Nove N vajo hived o in Na 4, arcURPLUS TRIGGERS 2.3.5.2 CALIFORNIA ALTERNATIVE S cited 1686 . 14Nelevations at which surplus conditions would be determined under the The Lake Mead o California Alternative are indicated by a series of tiered, sloping lines from the present to 2016. Each tiered line would be coupled with limitations on the amount of surplus water available at that tier. Figure 2-5 shows the structure of these tiered lines. Each tier is defined as a trigger line that rises gradually year by year to 2016, in recognition of the gradually increasing water demand of the Upper Division states. The elevations associated with the three tiers are as follows: Tier 1 - 1160 feet msl to 1166 feet msl Tier 2 - 1116 feet msl to 1125 feet msl Tier 3 - 1098 feet msl to 1102 feet msl Each tier under the California Alternative would be subject to adjustment during the interim period based on changes in Upper Basin demand projections or other factors during the five-year reviews or as a result of actual operating experience. The following sections describe the California Alternative tiers. When flood control releases are made, any and all beneficial uses would be met, including unlimited offstream storage. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-19 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 150 of 1200 DESCRIPTION OF ALTERNATIVES 2.3.5.2.1 CHAPTER 2 California Alternative Tier 1 California Alternative Tier 1 Lake Mead surplus trigger elevation increases from an initial elevation of 1160 feet msl to 1166 feet msl at the end of the interim period (based on Upper Basin demand projections). Lake Mead water surface elevations at or above the Tier 1 trigger line would permit surplus water deliveries to the Lower Division states in the estimated amounts on Table 2-5. The table also lists the estimated amounts of surplus water that would be available to the Lower Division states when flood control releases are required. Table 2-5 California Alternative Potential Surplus Water Supply Unit: thousand acre-feet (kaf) Year 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Flood Control 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 Tier 1 Tier 2 Tier 3 1350 1350 1350 1350 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 650 600 550 550 500 450 450 450 400 400 400 400 400 400 400 550 500 400 400 400 350 350 350 300 300 300 300 300 300 300 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. 2.3.5.2.2 California Alternative Tier 2 California Alternative Tier 2 Lake Mead surplus trigger elevation increases from 1116 feet msl to 1125 feet msl (based on Upper Basin demand projections). Lake Mead water surface elevations at or above the Tier 2 line (and below the Tier 1 line) would permit surplus water diversions for use by the Lower Division states in the estimated amounts on Table 2-5. 2.3.5.2.3 California Alternative Tier 3 California Alternative Tier 3 trigger elevation increases from 1098 feet msl to 1102 feet msl (based on Upper Basin demand projections). Lake Mead water surface elevations at or above the Tier 3 line (and below the Tier 2 line) would permit surplus water diversions for use by the Lower Division states in the estimated amounts on Table 2-5. When Lake Mead water levels are below the Tier 3 trigger elevation, surplus water would not be made available. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-20 1,000 2000 1,050 1,100 1,150 1,200 1,250 2005 2010 2015 2020 2-21 2025 Year 2030 2035 M INIM UM NEVADA PUM PING ELEVATIO N=1000 FT 2040 CALIFO RNIA'S TIER 3 RECOM M ENDATION (FOR COM PARISO N) 70R AVERAGE TRIGGER SPILLW AY ELEVATION=1221 FT ior Inter 17 e of th 29, 20 pt. . De ember v TIER 2=1116 TO 1125 ation on Nov N vajo hived Na TIER 3=1098 TO 1102 d in 64, arc cite 168 M INIM UM ELEVATION FO R POW ER GENERATION=1083 FT o. 14 N TIER 1=1160 TO 1166 AVERAGE FLOOD RELEASE TRIGGER Figure 2-5 California Alternative Surplus Trigger Elevations COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Lake Mead Elevation (f DESCRIPTION OF ALTERNATIVES 2045 2050 CHAPTER 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 151 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 152 of 1200 DESCRIPTION OF ALTERNATIVES 2.3.6 CHAPTER 2 SHORTAGE PROTECTION ALTERNATIVE 2.3.6.1 APPROACH TO SURPLUS WATER DETERMINATION The Shortage Protection Alternative is based on maintaining an amount of water in Lake Mead necessary to provide a normal annual supply of 7.5 maf for the Lower Division, 1.5 maf for Mexico and storage necessary to provide an 80 percent probability of avoiding future shortages. The modeling assumptions for shortage protection are discussed in Section 3.3.3.4, Lake Mead Water Level Protection Assumptions. 2.3.6.2 SURPLUS TRIGGERS The surplus triggers under this alternative range from an approximate Lake Mead initial elevation of 1126 feet msl to an elevation of 1155 feet msl at the end of the interim period, as shown on Figure 2-6. At Lake Mead elevations above the surplus trigger, surplus conditions would be determined to be in effect and surplus water would be available for use in the Lower Division states in the estimated amounts on Table 2-6. Below the trigger elevation, surplus water would not be made available. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ationControlNoveSurplus Year jo N Flood on Amount Nava archived 1350 1350 d in 20024, cite 1686 2003 1350 1350 1350 1350 . 14- 2004 No 2005 1350 1350 Table 2-6 Shortage Protection Alternative Potential Surplus Water Supply Unit: thousand acre-feet (kaf) 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2.4 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 1400 1450 1500 1550 1600 1600 1650 1650 1650 1700 1700 SUMMARY TABLE OF IMPACTS Table 2-7 presents a summary of the potential effects of the baseline operation and the interim surplus alternatives. Chapter 3 contains detailed descriptions of these effects. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2-22 1,000 2000 1,050 1,100 1,150 1,200 1,250 2005 2010 2015 2020 2-23 2025 Year 2030 2035 M INIM UM NEVADA PUM PING ELEVATIO N=1000 FT 70R AVERAGE TRIGGER SPILLW AY ELEVATION=1221 FT 2040 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 M IN IM U M ELEV A TIO N FO R PO W ER G EN ERA TIO N =1083 FT o. 14 N SHORTAGE PROTECTION ALTERNATIVE AVERAGE FLOOD RELEASE TRIGGER Figure 2-6 Shortage Protection Alternative Trigger Elevations COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Lake Mead Elevation (feet) DESCRIPTION OF ALTERNATIVES 2045 2050 CHAPTER 2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 153 of 1200 After 2016, median levels stabilize, then rise and fall slightly, due to 602(a) storage requirements and less frequent equalization releases. The probability of Lake Powell being full in 2016 is 27%. 3 Reservoir water levels exhibit a gradual declining trend during the interim surplus criteria period as a result of increasing Upper Division states consumptive use. The median water surface elevation in 2016 is 3665 feet msl. Baseline Conditions/No Action 2 3664 feet msl 3665 feet msl 3664 feet msl 3660 feet msl 3659 feet msl After 2016, Lake Powell water levels under all five alternatives tend to stabilize similar to baseline conditions. Water levels under the Basin States, Flood Control, Six States, California and Shortage Protection alternatives tend to converge with the baseline conditions by about year 2030. Basin States Flood Control Six States California Shortage Protection Median Elevations in 2016 for each of the alternatives are as follows: Effects of Alternatives Table 2-7 1 Summary of Potential Effects of Implementing Interim Surplus Criteria CHAPTER 2 2-24 Flows downstream of Hoover Dam are governed by downstream demand or Hoover Dam flood control releases. Flows downstream of Glen Canyon Dam would be managed in accordance with the 1995 Glen Canyon Dam EIS and the 1996 ROD. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Glen Canyon and Hoover Dam releases and flows downstream of Lake Mead. River Flows Other alternatives: Flows below Glen Canyon Dam would be similar to baseline conditions. Flows from Hoover Dam to Parker Dam would be moderately higher until 2016 because of surplus deliveries. After 2016, flows would be similar to baseline conditions. baseline conditions. Flood Control Alternative: Similar to baseline conditions. ior Inter 17 e of th 29, 20 Median Elevations in 2016 for each of the alternatives are as Lake Mead Water Surface Reservoir water levels exhibit a gradual pt. Elevations declining trend during the interim surplus criteria follows: er . De emb v period as a result of Lower Basin consumptive Potential changes in Lake Mead water 1143 feet msl ation on N v Basin States use exceeding long-term inflow. The median o surface elevations. Flood Control 1162 feet msl water surface elevation in 2016 isd ajo N ive 1162 feet v Six States 1146 feet msl msl. Na ch in California 1131 feet msl d After 2016,64, ar surface elevations cite continue8 median water at a lower rate, Shortage Protection 1130 feet msl decline, 4-16 to frequent although surplus 1 Lower Basin After 2016, median surface elevations continue to decline. By No. due to less deliveries. about 2035, all alternatives converge to elevations similar to Potential changes in Lake Powell water surface elevations. Lake Powell Water Surface Elevations Reservoirs Elevations and River Flows Resource/Issue DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 154 of 1200 2002 through 2016 2017 through 2050 2002 through 2016 2017 through 2050 2002 through 2016 2017 through 2050 Surplus: Shortage: Normal: Surplus: 2002 through 2016 2017 through 2050 Normal: >96% 50% 0% 0% 47% 21% 100% 100% Baseline Conditions/No Action 2 Other Alternatives: Greater probability of surplus through 2016 under the California and Shortage Protection alternatives and slightly lower (26%) under the Basin States and Six States alternatives. The probability of surplus under the alternatives is about the same as baseline from 2017 to 2050. The probability of shortage condition deliveries under the alternatives is slightly higher (7% to 14%) through 2016. From 2017 to 2050, the probability of shortages under the alternatives is similar to baseline conditions. Flood Control Alternative: Similar to baseline conditions. Other Alternatives: Greater probability of surplus through 2016. The probability is similar to baseline conditions from 2017 through 2050. Deliveries less than the normal apportionment (4.4 mafy) do not occur under the alternatives at any time through 2050. Flood Control Alternative: Similar to baseline conditions. Effects of Alternatives Table 2-7 1 Summary of Potential Effects of Implementing Interim Surplus Criteria CHAPTER 2 100% 100% 2002 through 2016 2017 through 2050 2002 through 2016 2016 through 2050 2002 through 2016 2017 through 2050 Normal: Surplus: Shortage: 2-25 0% 0% 26% 19% < 4% 50% 29% 21% Shortage: 2002 through 2016 2017 through 2050 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Probabilities of meeting Treaty delivery obligations. Mexico Treaty Delivery 4 2002 through 2016 2017 through 2050 The Flood Control Alternative would provide slightly higher (1%) probabilities of surplus than under baseline conditions through 2016. The rest of the alternatives provide slightly lower (3% to 7%) probabilities of surplus through 2016 and about the same level as baseline through 2050. Deliveries less than the treaty apportionment (1.5 mafy) do not occur under the alternatives at any time through 2050. the alternatives through 2016. From 2017 to 2050, the probability of shortage condition deliveries is higher (3% to 5%) under the alternatives. ior Inter 17 e of th 29, 20 Shortage: 2002 through 2016 < 4% t. 2017 through 2050 D p .50%e ember v ation on Nov N vajo hived n Na 2002 arc d iNormal: 64, through 2016 96% Nevada Water Supply Flood Control Alternative: Similar to baseline conditions. cite 168 2017 through 2050 50% Probabilities of normal, surplus and Other Alternatives: Greater probability of surplus through 2015; shortage conditions. same as baseline from 2017 to 2050. The probability of o. 14 Surplus: 2002 through 2016 47% N shortage condition deliveries is slightly higher (7% to 14%) for 2017 through 2050 21% Probabilities of normal, surplus and 4 shortage conditions. Arizona Water Supply Probabilities of normal, surplus and 4 shortage conditions. California Water Supply Water Supply Resource/Issue DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 155 of 1200 2 Modeling indicates potential for slight reductions in salinity under each alternative as compared to baseline. Effects of Alternatives Increased potential for lower Lake Mead levels and increased inflow channel lengths under baseline projections could increase potential of elevated contaminant concentrations. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Potential effects on Lake Mead and Lake Powell fisheries and associated aquatic habitat. Lake Habitat and Sport Fisheries 2-26 Species are adapted to fluctuating reservoir levels. Therefore, increased potential for lower Lake Mead and Lake Powell surface levels is not expected to adversely affect aquatic species. Compared with baseline conditions, slightly increased potential for higher reservoir levels under the Flood Control Alternative and increased potential for lower reservoir levels under the other alternatives would not be expected to result in substantial changes to lake habitat. Davis and Parker Dams. Aquatic Resources under baseline conditions. Parker Dam 10% Average annual probability from 2017 through 2050: Davis Dam 5% Parker Dam 6% Beach/Habitat-Building Flow Releases ior Inter 17 e Probability of BHBF release conditions of th 29, 20 from Glen Canyon Dam. pt. . De ember ion v N v Low Steady Summer Flows The average annual Nat probability of conditions o The probability under the alternatives is typically less than on requisite for lowjsteady summer flows is 38% under baseline conditions during the first seven years and Probability of requisite conditions for v o e through through a and 62% from v similar to or slightly greater than under baseline conditions N2016a archi 2017d low steady summer flow releases from in thereafter. d 2050. 64, Glen Canyon Dam. cite 168 Flooding Downstream of Hoover Average annual probability from 2002 through The probability under the Flood Control Alternative is slightly Dam 2016: greater than under baseline conditions. o. 14 N Davis Dam 9% Probability of damaging flows below The probability under other alternatives is slightly less than The probability under the alternatives is typically less than under baseline conditions during the interim period, and converges with baseline conditions thereafter. The alternatives, except the Flood Control Alternative, result in slightly increased potential for increased contaminant concentrations in Boulder Basin, due to greater potential for lower Lake Mead levels than under baseline conditions. Baseline projections assume compliance with numeric criteria along the river. The Basin States are committed to meeting the numeric criteria. Baseline Conditions/No Action Table 2-7 1 Summary of Potential Effects of Implementing Interim Surplus Criteria CHAPTER 2 The average annual probability of BHBF releases is 16% through 2016 and 14% from 2017 through 2050. Flow-Related Issues Contaminant concentrations in Boulder Basin of Lake Mead, in proximity to the SNWS intakes at Saddle Island. Lake Mead Water Quality and Las Vegas Water Supply Potential change in salinity below Hoover Dam. Colorado River Salinity Water Quality Resource/Issue DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 156 of 1200 2 Although reservoir elevations would differ, the effects of all alternatives would be similar to baseline conditions. Effects of Alternatives The Flood Control Alternative would have slightly lower potential, while the other alternatives would have increased potential, for lower reservoir elevations and associated potential increases in delta habitat. Under baseline conditions, special-status plant species would continue to be affected by fluctuating water levels, which would periodically expose and inundate areas where the plants occur. Baseline Conditions/No Action Table 2-7 1 Summary of Potential Effects of Implementing Interim Surplus Criteria CHAPTER 2 Under baseline conditions, increased potential over time for lower reservoir levels could increase potential for development of temporary riparian habitat at the deltas, which would benefit special-status wildlife species that utilize such habitat. The Flood Control Alternative has slightly lower potential, and each of the other alternatives have higher potential, for each of navigation hazards and reduced carrying capacity. Boaters may have reduced take-out opportunities due to increased potential for lower reservoir surface elevations. 2-27 The Flood Control Alternative has lower potential, and each of the other alternatives have increased potential, for reduced take-out opportunities resulting from lower reservoir elevations. Baseline condition projections indicate an increased potential for the occurrence of lower Lake Mead and Lake Powell reservoir levels, which may result in potential increases in navigation hazards and decreased safe boating capacity (due to decreased reservoir surface area). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Potential effects on river boating at Lake Powell and Lake Mead inflow areas. River and Whitewater Boating Potential effects on reservoir boating that may result from changes in Lake Mead and Lake Powell surface elevations. Reservoir Boating/Navigation facilities to accommodate lower surface elevations. rior Intefor lower reservoir levels under the various Special-Status Fish Under baseline conditions, increased potential Changes in potential e for lower elevations is not expected to have alternatives would not change potential for effects. of th 29, 2017 Potential effects of Lake Mead and . effects on special-status species fish different pt Lake Powell reservoir level changes . De ember than those that occur at present. v on special-status fish species. n Natio d on Nov Recreation vajo Reservoir Marinas/Boat Launching Baseline condition projections indicate Flood Control a decreased Napotentialarchivelevels lower Thelower reservoir Alternative hastheslightly alternativespotential in for levels; each of other have d increased 64, for reservoir normal Potential effects on shoreline t ciine than those considered within the increased potential for lower levels and necessary relocations. recreation facilities from changes -168 operating range that some existing facilities Lake Mead and Lake Powell surface 14 to accommodate. elevations. No. may be ablewould likely result inSuch occurrence modification of Potential effects on special-status wildlife species associated primarily with potential effects on riparian habitat at the Lake Mead and Virgin River deltas, and the lower Grand Canyon. Special-Status Wildlife Potential effects on special-status plants for areas influenced by Lake Powell and Lake Mead water levels. Special-Status Plants Special-Status Species Resource/Issue DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 157 of 1200 The Flood Control Alternative is similar to baseline conditions. The Flood Control Alternative is similar to baseline conditions. Other alternatives have greater potential for increased relocation costs, based on an average cost per foot associated with relocating facilities. Baseline condition projections indicate increased relocation costs associated with future increased potential for lower reservoir levels. Glen Canyon Powerplant average annual energy production: Changes in reservoir elevations under each of the alternatives would not be expected to adversely affect sport fisheries or fishing in either reservoir. Potential effects on sport fisheries are minimal under baseline conditions. CHAPTER 2 2-28 4532 GWh through 2016; 4086 GWh from 2017 through 2050. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Potential for changes in energy production at Glen Canyon and Hoover powerplants. California Shortage Protection $544,843 $532,635 Average annual power production under the other alternatives is greater than under baseline conditions for the first six to eight years, then is less for the remaining years. Averaged from 2002 to 2050, Glen Canyon annual power production is from 12 to 30 GWh less than baseline conditions, while Hoover power production is from 51 to 127 GWh less. ior Inter 17 e Hoover Powerplant average annual energy of th 29, 20 production: ept. . D2017 ember vfrom 4685 GWh through 2016; 3903 n atio GWh on Nov through 2050. jo N ve water vaverage Lake iMeadd levels The increase over baseline conditions of annual pumping costs Pumping Power Needs for SNWS Future lower a for each alternative follows: in Na 4, arch Potential change in the cost of power d would require more energy and increased costs cite pumping86 for the SNWS intake. to pump Lake Mead water through the 6 Basin States $229,395 SNWS. 14-1 Flood Control $ 32,685 o. N Six States $214,779 Hydroelectric Power Production Energy Resources Increased costs associated with relocating shoreline facilities to remain in operation at lower reservoir elevations. Recreation Facilities Relocation Costs Potential effects on sport fishing in Lake Mead and Lake Powell. Reservoir Sport Fishing DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 158 of 1200 Increased potential for lower reservoir levels would increase potential for shoreline exposure under baseline conditions. Increases in fugitive dust emissions would be minimal due to low emission potential of shoreline. Future lower average Lake Powell water levels would require more energy and increased pumping costs for the Navajo Generating Station and the City of Page. $ 529 $ 0 $ 508 $1,110 $1,112 Slightly decreased shoreline exposure under Flood Control Alternative would lower fugitive dust emission potential. Other alternatives would have slightly increased potential for increased fugitive dust emissions. Minimal changes in areawide fugitive dust emissions would be expected. City of Page Basin States Flood Control Six States California Shortage Protection The increase over baseline conditions of annual pumping costs for each alternative follows: Navajo Generating Station Basin States $2,216 Flood Control $ 0 Six States $2,129 California $4,651 Shortage Protection $4,660 CHAPTER 2 2-29 There is a probability of shortages of CAP priority water for tribes in central Arizona. The water available to members of Ten Tribes Partnership would not be affected by future changes under baseline conditions. Not significant due to past water level fluctuations. Impacts have already occurred. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Effects on water supply for Indian Tribes and Communities Indian Trust Assets Effects on Historic Properties in Operational Zone of Reservoir and River Reaches. Cultural Resources Fugitive Dust Emissions from Exposed Reservoir Shoreline Greater probability of shortages of CAP priority water for tribes in central Arizona under all alternatives with the exception of the Flood Control Alternative. No effect on water available to members of Ten Tribes Partnership. Not significant due to past water level fluctuations. Impacts have already occurred. ior Inter 17 e Potential for fugitive dust emissions of th 29, 20 pt. from shoreline exposure at Lake Mead . De ember v and Lake Powell. ation on Nov Visual Resources N vajo hived Visual Attractiveness of Reservoir Increased probability of temporary degradation Flood Control Alternative: Same as baseline conditions. Scenery, Lake Mead and Lake in visual attractivenessc shoreline vistas in Na 4, ar of Powell from lower cited resulting86inincreasing potential forPowell. Other alternatives: Higher probability of degradation of visual attractiveness through 2016 due to accelerated decline of water6 -1 levels Lake Mead and Lake Potential effects of lower reservoir minimum reservoir levels. 4 1 elevations on scenic quality. No. Air Quality Potential change in the cost of power to pump Lake Powell water to the Navajo Generating Station and the City of Page. Intake Energy Requirements at Lake Powell DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 159 of 1200 2002 through 2016 2017 through 2050 2002 through 2016 2017 through 2050 Surplus: Shortage: 0% 0% 26% 19% 100% 100% Probability of excess flows below Morelos Dam would gradually decline under baseline conditions. 2002 through 2016 2016 through 2050 Normal: No effects are anticipated. Flood Control Alternative: Similar to baseline. The Flood Control Alternative would provide slightly higher (1%) probabilities of surplus than under baseline conditions 2016. The rest of the alternatives provide slightly lower (3% to 7%) probabilities of surpluses through 2016 and about the same level as baseline through 2050. Deliveries less than the treaty apportionment (1.5 mafy) do not occur under the alternatives at any time through 2050. No effects anticipated. CHAPTER 2 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Amount of excess flow that may reach the Colorado River delta. 2-30 Other alternatives: Small reduction in probability of excess flows. r terio InStates Alternative there would be no effect on Potential Effects on Species and Probability of excess flows below Morelos Dam Under the 1 clapper of the BasinVaquita, Yuma7 rail, California Habitat in Mexico would gradually decline. desert t.Clarks pupfish,and9, 2is0 likely to be any adverseblack rail, p ber 2 v. De vtotoaba, Southwestern willow flycatcher, Yellow-billedaffect on mgrebe; there not cuckoo, n e Natio d on No Elf owl or Bell's vireo. jomodeling ofve 1. Effects identified are based on probabilities developedva through discussed in detail in Chapter Na throughaconditionspossiblebefuture conditionsnear 2016,2050,year in which the interim surplus3.criteria would greatest at or the 2. In general, the differences between the alternatives and baseline chi would n terminate. ted i 686lake r c essentially full when the 4, elevation reaches 3695 feet msl (5 feet below the top of the spillway gates). 3. Lake Powell is considered to be i -1 4. Probabilities of shortage are based on the modeling assumption of protecting a Lake Mead elevation of 1083 feet msl. There are no established shortage criteria for the operation of Lake Mead. o. 14 N Flow Below Morelos Dam Probabilities of meeting Treaty delivery obligations Treaty Water Delivery Obligations Transboundary Effects Exposure of Minority or Low Income Communities to Health or Environmental Hazards Environmental Justice DESCRIPTION OF ALTERNATIVES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 160 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 161 of 1200 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 162 of 1200 3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES 3.1 INTRODUCTION Chapter 3 presents the analysis conducted and identifies potential effects that could occur as a result of implementation of the interim surplus criteria alternatives under consideration. Section 3.1 describes the: 1) structure of the resource sections in this chapter; 2) role of modeling in the analysis; 3) baseline used for measuring potential effects of the alternatives; 4) general approach used for determining potential effects; 5) period of analysis; and 6) environmental commitments associated with interim surplus criteria. Section 3.2 presents a general discussion of the geographic area within which potential effects of the interim surplus criteria were analyzed, and Section 3.3 describes the modeling methods and general results of Colorado River system modeling. The remaining sections of Chapter 3 present resource-specific analyses of potential effects using information obtained from the modeling. rior Inte f the 9, 2017 3.1.1 STRUCTURE OF RESOURCE SECTIONS o pt. . De ember 2 v ion v chapter Beginning with Section 3.4, the jo Nat in this n No each present a general resource sections arecreationed o v iv category, such as water supply, in Na arch and aquatic resources. Within each resource d analyses 4, one or more specific issues identified for ite category is contained c 1686 of consideration through scoping, public review and comment, and internal review. A . 14No discussion of the methodology, affected environment and environmental consequences is provided for each issue. Environmental commitments are proposed for impacts to various resource issues as appropriate. Methodology discussions identify the specific methods used for determining the affected environment and potential environmental consequences of the alternatives. The affected environment discussions then identify the specific context within which the issue being analyzed exists. This includes a discussion of general environmental characteristics associated with each issue, as well as important Colorado River system conditions that may be associated with each issue. Finally, the potential effects of interim surplus criteria compared to baseline conditions (as discussed in more detail below) are presented in the environmental consequences discussions. 3.1.2 USE OF MODELING TO IDENTIFY POTENTIAL FUTURE COLORADO RIVER SYSTEM CONDITIONS To determine the potential effects of the interim surplus criteria alternatives, modeling of the Colorado River system was conducted (a complete description of the modeling COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.1-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 163 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 procedure is included in Section 3.3). Modeling provides projections of potential future Colorado River system conditions (i.e., reservoir surface elevations, river flows, salinity, etc.). The modeling results allow a comparison of potential future conditions under the various interim surplus criteria alternatives and baseline conditions. As such, much of the analyses contained within this FEIS are based upon potential effects of changed flows and water levels within the Colorado River and mainstream reservoirs. 3.1.3 BASELINE CONDITIONS As discussed in Chapter 2, the No Action Alternative does not provide consistent specific criteria for determining surplus conditions. As such, it is not possible to precisely model the No Action Alternative. However, in order to provide a reasonable analytical projection of potential future system conditions without interim surplus criteria, a baseline surplus strategy (70R) was utilized. This baseline represents definable surplus criteria based on recent operational decisions. The 70R strategy is based upon recent secretarial operating decisions and was modeled to develop a projection of baseline conditions for comparison with the alternatives in this FEIS. 3.1.4 IMPACT DETERMINATION rior The analysis of potential effects for each issue considered ishe Intprimarily upon the based e 7 f t important1to each issue, results of modeling. Following the identification ofpt. o conditions 29, 20 . De ber the potential effects of various system conditions overvthe general range of their ion v No em Nat possible occurrence (as identified by the range of modeling output for various vajo issue.ved on parameters) are identifiedNa each rchi The potential effects of the various interim d in for , a surplus criteria cite -16864 alternatives are then presented in terms of the incremental differences in probabilities (or o. 14 circumstances associated with a given probability) between N projected baseline conditions and the alternatives. 3.1.5 PERIOD OF ANALYSIS This FEIS addresses interim surplus criteria that would be used during the years 2001 through 2015 for determining whether surplus water would be available during the years 2002 through 2016. Due to the potential for effects beyond the 15-year interim period, the modeling and impact analyses extend through the year 2050. It is important to note that modeling output and associated impact analyses become more uncertain over time as a result of increased uncertainty of future system conditions (including hydrologic conditions), as well as uncertainty with regard to future operational decisions that will affect circumstances within the Colorado River system. 3.1.6 ENVIRONMENTAL COMMITMENTS As discussed, impacts identified in Chapter 3 are associated with changes in the difference between probabilities of occurrence for specific resource issues under study when comparing the action alternatives to baseline conditions. Reclamation has COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.1-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 164 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 determined that most of the potential impacts identified are not of a magnitude that would require specific mitigation measures to reduce or eliminate their occurrence because the small changes in probabilities of occurrence are within Reclamation’s current operational regime and authorities under applicable federal law. However, in recognition of potential effects that could occur under baseline conditions or with implementation of the interim surplus criteria alternatives under consideration, Reclamation has developed a number of environmental commitments that would be undertaken if interim surplus criteria are implemented. These commitments are described in relevant resource sections of this Chapter and in Section 3.17. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.1-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 165 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.2 CHAPTER 3 POTENTIALLY AFFECTED AREA Interim surplus criteria could affect the operation of the Colorado River system (i.e., reservoir levels and river flow volumes) as a result of surplus determinations and associated water deliveries that may not have occurred in the absence of such criteria. This section describes the general geographic scope in which specific issues and potential effects associated with the interim surplus criteria alternatives were considered in this FEIS. Also discussed are the AMP, and how the program influences flows between Lake Powell and Lake Mead. In addition to influencing conditions within the Colorado River system, it is recognized that continued delivery of surplus water that could result from interim surplus criteria would complement ongoing and proposed state actions in the Lower Basin. These actions could result in environmental effects outside of the river corridor. However, these actions have independent utility and are not caused by or dependent on interim surplus criteria for their implementation. Environmental compliance would be required on a case-by-case basis prior to their implementation. Therefore, Reclamation determined that the appropriate scope of this analysis is to consider only those potential effects that could occur within the Colorado River corridor as defined by the 100-year r flood plain and reservoir maximum water surface elevations. terio e In 7 of h 29, 2 Water . andthydrology. 01 supply to pt Interim surplus criteria are based on system conditions . De ber the Lower Division states of Arizona,ation v and Nevada is achieved primarily California Novem N Mead. through releases and pumping ajo Lake ed on As a result of Lake Powell and Lake from iv Nav (discussed further in Section 3.3), interim surplus in Mead equalization requirements, arch ited 6864 c criteria effects on Lake-Mead surface elevations could also influence Lake Powell 14 1 o.and Glen Canyon Dam releases. However, operation of the other N surface elevations Upper Basin reservoirs is independent of Lake Powell. Therefore, the upstream limit of the potentially affected area under consideration in this FEIS is the full pool elevation of Lake Powell. The downstream limit of the potentially affected area within the United States is the SIB between the United States and Mexico. Section 3.16 of this FEIS addresses potential transboundary impacts in Mexico extending to the mouth of the Colorado River as required pursuant to Executive Order 12114 - Environmental Effects Abroad of Major Federal Actions, January 4, 1997, and the July 1, 1997 Council on Environmental Quality (CEQ) Guidelines on NEPA Analyses for Transboundary Impacts. 3.2.1 COLORADO RIVER SEGMENTS AND ISSUES ADDRESSED As shown on Map 3.2-1, the Colorado River corridor from Lake Powell to Mexico consists of flowing river reaches, two large reservoirs (Lake Powell and Lake Mead) and two smaller reservoirs downstream of Lake Mead (Lake Mohave and Lake Havasu). The river corridor and adjacent areas comprise a heterogeneous composite of various geographic and hydrologic regimes, which differ in their resource composition and resource management administration. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.2-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 166 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Map 3.2-1 Area of Potential Effect ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.2-2 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 167 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 For the purposes of presentation, and to focus analysis of the potential effects of the interim surplus criteria, the river corridor has been divided into four areas: Lake Powell, the Colorado River between Glen Canyon Dam and Lake Mead, Lake Mead, and the Colorado River between Hoover Dam and the SIB. The following sections discuss the areas segmented for this analysis and introduce the issues considered within each area. 3.2.1.1 LAKE POWELL Lake Powell is a large reservoir on the Colorado River formed by Glen Canyon Dam. The reservoir is narrow and long (over 100 miles). Lake Powell provides water storage for use in meeting delivery requirements to the Lower Basin. The normal operating range of Lake Powell is between elevations 3490 and 3700 feet msl. Elevation 3490 feet msl corresponds to minimum power pool. (Releases from Glen Canyon Dam can be made below 3490 feet msl down to elevation 3370 feet msl via the river bypass tubes.) Elevation 3700 feet msl corresponds to the top of the spillway radial gates. During floods, the elevation of Lake Powell can go above 3700 feet msl by raising the radial spillway gates, resulting in spillway releases. In 1983, Lake Powell reached a high elevation of 3708.34 feet msl. rior Inte f the 9, 2017 Lake Powell is located within the GCNRA, whichepadministered by the NPS. is t. o r . D operation of 2 Canyon Dam and Reclamation retains authority and discretion v the vembe Glen ion for No Nat d on Lake Powell. Issues considered jin this FEIS associated with Lake Powell include: va o surface elevations); salinity; aquatic resources; ive hydrology (i.e., projectedNa d in reservoir rch , afacilities, boating and sport fishing; power cite 16864 special-status species; recreational generation from o. 14 N Glen Canyon Dam; changes in pumping costs for Navajo Generating Station and the City of Page; visual and air quality effects associated with exposed reservoir shoreline; environmental justice; cultural resources; and Indian Trust Assets (ITAs). 3.2.1.2 COLORADO RIVER FROM GLEN CANYON DAM TO LAKE MEAD The segment of the Colorado River between Glen Canyon Dam and Lake Mead is comprised of a narrow river corridor through the Grand Canyon that is administered primarily by the Grand Canyon National Park. Flows within this reach of the river consist primarily of releases from Glen Canyon Dam as discussed in Section 3.3.1. Issues considered in this FEIS within this segment of the river address those associated with a program of low steady summer flows and Beach/Habitat-Building Flow (BHBF) releases, as discussed in Section 3.2.2. 3.2.1.3 LAKE MEAD Lake Mead is a large reservoir on the Colorado River formed by Hoover Dam. The reservoir provides water storage for use in regulating the water supply and meeting COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.2-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 168 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 delivery requirements in the Lower Basin. The normal operating range of the reservoir is between elevations 1219.61 and 1083 msl. Elevation 1083 msl corresponds to the minimum power pool. (Releases can be made from Hoover Dam below 1083 msl down to 895 feel msl via the intake towers.) During floods, the elevation of Lake Mead can go above 1219.61 msl. The top of the raised spillway gates is at 1221.0 msl. Since its initial filling in the late 1930s, the reservoir water level has fluctuated from a high of 1225.85 feet msl (as occurred in July, 1983) to a low of 1083.21 feet msl (as occurred in April, 1956). The reservoir is located within the LMNRA, which is administered by the NPS. However, Reclamation retains authority and discretion for the operation of Hoover Dam and Lake Mead. Issues considered in this FEIS associated with Lake Mead include: hydrology; water supply for Nevada; salinity; water quality associated with Las Vegas Wash and SNWA intakes; aquatic resources; special-status species; recreational facilities, boating and sport fishing; power generation from Hoover Dam; visual and air quality effects associated with exposed reservoir shoreline; environmental justice; cultural resources; and ITAs. 3.2.1.4 COLORADO RIVER FROM HOOVER DAM TO THE SOUTHERLY INTERNATIONAL BOUNDARY erior Int 7 f thewithin201shallow The Colorado River from Hoover Dam to the SIBepcontained r 29, the is t. o v. D mbe Colorado River Valley in which Lake Mohave, Lake Havasu and other smaller ation segment,ve No especially along river reaches diversion reservoirs are located. jo N this on ava Within ved below Parker Dam, d in N the Colorado River iis fringed with riparian vegetation and marshy arch te cicontains 6864, of diversion dams and a system of levees. The backwaters, and 4-1 a number northern reachNothis segment, including Lake Mohave, lies within the LMNRA. The of . 1 lower reach is bordered by a combination of federal, Tribal and private land. The last 22 miles (approximately) is along the international border with Mexico. Reclamation retains authority and discretion for river operations in the reaches of this segment. Under the BCPA and the Decree, discussed previously in Chapter 1, releases from Hoover Dam are governed by orders for downstream water deliveries to Arizona, California, Nevada and Mexico. However, releases may exceed orders when flood releases are required under the Corps’ flood control criteria, as discussed in Chapter 1 or for other purposes consistent with the BCPA and the Decree. Issues considered in this FEIS associated with this river segment include hydrology; water supply for Arizona, California, Nevada and Mexico; costs of flood damages downstream of Hoover Dam; water quality; potential effects of changes in flows on special-status species; potential effects of changes in the temperature of water released from Hoover Dam on sport fisheries and fishing; environmental justice; cultural resources; and ITAs. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.2-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 169 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.2.2 CHAPTER 3 ADAPTIVE MANAGEMENT PROGRAM INFLUENCE ON GLEN CANYON DAM RELEASES In March 1995, Reclamation completed an EIS on the operation of Glen Canyon Dam. The EIS developed and analyzed alternative operation scenarios designed to meet statutory responsibilities for conserving downstream resources, while meeting other authorized project purposes, and protecting Native American interests. Major issues of concern included native and endangered species, beach erosion, recreation (including white-water boating, sport fishing, and camping), vegetation, wildlife habitat and food base, water supply, hydroelectric power generation, cultural resources, and Native American interests. The Secretary signed a ROD on October 8, 1996, which specified certain types of releases from Glen Canyon Dam. Prior to the ROD, Glen Canyon Dam was operated as a peaking power facility, maximizing the value of power produced. The patterns of releases resulting from this type of operation were recognized to be detrimental to downstream resources and were therefore modified by the ROD. Reclamation also consulted with the Service under the ESA. The Service issued a biological opinion containing a recommendation for a reasonable and prudent alternative, which was incorporated into the ROD (see Section 1.4.2.1). To determine if the operation of Glen Canyon Dam under the RODerimeeting the is or Int as 17 objectives of downstream resource protection, an AMP washe instituted 0 described in of t 9 2 Section 1.4.2.1. Through this process, the effects epdam operations, and the status of of t. . Dare used to er 2 b formulate potential em resources are monitored and studied. ation v The results N refinements Nov operations to ensure that the n to dam recommendations to the Secretary on ved o vajo in Na 4, archi Act are met. As long as the AMP continues purposes of the Grand Canyon Protection ited 6 to successfully c function,168natural and cultural resources within the Colorado River the . 14corridor between Glen Canyon Dam and Separation Canyon (just upstream of Lake No Mead) will be protected and conserved. Two types of releases from Glen Canyon Dam, BHBFs and low steady summer flows, are part of a program of experimental flows being developed and refined through the AMP, as called for in the Biological Opinion (USFWS, 1994). The change in the frequency with which BHBFs and low steady summer flows would be triggered under each of the alternatives has been analyzed (see Section 3.6). Flows from Glen Canyon Dam, which could be affected by the adoption of interim surplus criteria, will remain within the range of flows analyzed in detail in the Glen Canyon Dam EIS. Therefore, effects of potential changes in the frequencies of these flows on downstream resources require no further analysis outside of the Glen Canyon Dam ROD and the AMP. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.2-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 170 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.3 RIVER SYSTEM OPERATIONS This section addresses the operation of the Colorado River system, the modeling process used to simulate river operation and potential changes that may occur from implementation of the interim surplus criteria. The term system management refers to how the water is managed once it enters the Colorado River system and includes operation of the system reservoirs, dams and other Colorado River system facilities. The environmental and socioeconomic effects of the interim surplus criteria alternatives stem from changes in the operation of the Colorado River system under the surplus alternatives relative to the baseline conditions. 3.3.1 OPERATION OF THE COLORADO RIVER SYSTEM Operation of the Colorado River system and delivery of Colorado River water to the seven Basin States and Mexico are conducted in accordance with the Law of the River as discussed in Section 1.3.2.1. Water cannot be released from storage unless there is a reasonable beneficial use for the water. The exceptions to this are releases required for flood control, river regulation or dam safety. In the Lower Basin, water is released from the system to satisfy water delivery orders and to satisfy other purposes set forth in the Decree. The principal facilities that were built to manage the watererior Colorado t in the River System include Glen Canyon Dam and Hoover Dam.the In 017 f 9, 2 pt. o . De ember 2 LROC and the The Colorado River system is operatedtbyn v Reclamation pursuant to Nov Na io d The AOP is formulated for the upcoming AOP. The AOP is required byajo CRBPA. on the av ive year under a varietyd in N of potential ,scenarios or conditions. The plan is developed based arch cite existing4 on projected demands, -1686 storage conditions and probable inflows. The AOP is 14 prepared by Reclamation, acting on behalf of the Secretary, in consultation with the No. Basin States, the Upper Colorado River Commission, Indian tribes, appropriate federal agencies, representatives of the academic and scientific communities, environmental organizations, the recreation industry, water delivery contractors, contractors for the purpose of federal power, others interested in Colorado River operations, and the general public. Prior to the beginning of the calendar year, Lower Basin diversion schedules are requested from water users entitled to Colorado River water as discussed in Section 3.4. These schedules are estimated monthly diversions and return flows that allow Reclamation to determine a tentative schedule of monthly releases through the Hoover Powerplant. Actual monthly releases are determined by the demand for water downstream of Hoover Dam. Daily changes in water orders are made to accommodate emergencies, temperature and weather. A minimum of 1.5 maf is delivered annually to Mexico in accordance with the Treaty. The Treaty contains provisions for delivery of up to 200,000 af above the 1.5 maf when there exists water in excess of that necessary to satisfy the uses in the United States and the guaranteed quantity of 1.5 maf to Mexico. Additionally, excess flows above the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 171 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 200,000 af may become available to Mexico coincident with Lake Mead flood control releases and Gila River flood flows provided that the reasonable beneficial uses of the Lower Division states have been satisfied. 3.3.1.1 OPERATION OF GLEN CANYON DAM Flows below Glen Canyon Dam are influenced by storage and release decisions that are scheduled and implemented on an annual, monthly and hourly basis from Glen Canyon Dam. The annual volume of water released from Glen Canyon Dam is made according to the provisions of the LROC that includes a minimum objective release of 8.23 maf, storage equalization between Lake Powell and Lake Mead under prescribed conditions and the avoidance of spills. Annual releases from Lake Powell greater than the minimum occur if Upper Basin storage is greater than the storage required by Section 602(a) of the CRBPA, and if the storage in Lake Powell is greater than the storage in Lake Mead. Annual release volumes greater than the minimum objective of 8.23 maf are also made to avoid anticipated spills. Monthly operational decisions are generally intermediate targets neededrto terio systematically achieve the annual operating requirements. The actual volume of water he In 2017 of t released from Lake Powell each month depends on pt. forecasted 9, e the ber 2 inflow, storage D targets and annual release requirements idescribed above.m Demand for energy is also n v. at othe annualove and storage requirements considered and accommodatedajolong as d on N release as N v ive are not affected. d in Na arch cite 16864, 14The National Weather Service Colorado Basin River Forecast Center (CBRFC) No. provides the monthly forecasts of expected inflow into Lake Powell. The CBRFC uses a satellite-telemetered network of hundreds of data collection points within the Upper Colorado River Basin that gather data on snow water content, precipitation, temperature and streamflow. Regression and real-time conceptual computer models are used to forecast inflows that are then used by Reclamation to plan future release volumes. Due to the variability in climatic conditions, modeling and data errors, these forecasts are based, in part, on large uncertainties. The greatest period of uncertainty occurs in early winter and decreases as the snow accumulation period progresses into the snowmelt season, often forcing modifications to the monthly schedule of releases. An objective in the operation of Glen Canyon Dam is to attempt to safely fill Lake Powell each summer. When carryover storage from the previous year in combination with forecasted inflow allows, Lake Powell is targeted to reach a storage of about 23.8 maf in July (0.5 maf from full pool). In years when Lake Powell fills or nearly fills in the summer, releases in the late summer and early winter are generally made to draw the reservoir level down, so that there is at least 2.4 maf of vacant space in Lake Powell on January 1. Storage targets are always reached in a manner consistent with the LROC. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 172 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Scheduling of BHBF releases from Glen Canyon Dam are discussed in Section 3.6.2.2. Daily and hourly releases are made according to the parameters of the ROD for the Operation of Glen Canyon Dam Final Environmental Impact Statement and published in the Glen Canyon Dam Operating Criteria (62 CFR 9447, Mar. 3, 1997), as shown in Table 3.3-1. Table 3.3-1 Glen Canyon Dam Release Restrictions Parameter 1 Maximum Flow Minimum Flow Ramp Rates Ascending Descending 2 Daily Fluctuations 1 Cubic Feet per Second 25,000 5,000 8,000 4,000 1,500 5,000 to 8,000 Conditions Nighttime 7:00 a.m. to 7:00 p.m. Per hour Per hour To be evaluated and potentially increased as necessary and in years when delivery to the Lower Basin exceeds 8.23 maf. Daily fluctuation limit is 5,000 cfs for months with release volumes less than 0.6 maf; 6,000 cfs for monthly release volumes of 0.6 maf to 0.8 maf; and 8,000 cfs for monthly volumes over 0.8 maf. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N 3.3.1.2 OPERATION OF HOOVER Dchived Nava ar AM in cited 16864, Hoover Dam is managed to provide at least 7.5 maf annually for consumptive use by 14No. the Lower Division states plus the United States’ obligation to Mexico. Hoover Dam 2 releases are managed on an hourly basis to maximize the value of generated power by providing peaking during high-demand periods. This results in fluctuating flows below Hoover Dam that can range from 1,000 cubic feet per second (cfs) to 49,000 cfs. The upper value is the maximum flow-through capacity through the powerplant at Hoover Dam (49,000 cfs). However, because these flows enter Lake Mohave downstream, the affected zone of fluctuation is only a few miles. Releases of water from Hoover Dam may also be affected by the Secretary’s determinations relating to normal, surplus or shortage water supply conditions, as discussed in Section 1.3.4.1. Another type of release includes flood control releases. For Hoover Dam, flood control releases are defined in this FEIS as releases in excess of the downstream demands. Flood control was specified as a primary project purpose by the BCPA, the act authorizing Hoover Dam. The Corps is responsible for developing the flood control operation plan for Hoover Dam and Lake Mead as indicated in 33 CFR 208.11. The plan is the result of a coordinated effort by the Corps and Reclamation. However, the Corps is responsible for providing the flood control regulations and has authority for COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 173 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 final approval of the plan. Any deviations from the flood control operating instructions provided by the plan must be authorized by the Corps. The Secretary is responsible for operating Hoover Dam in accordance with these regulations. Lake Mead’s uppermost 1.5 maf of storage capacity, between elevations 1219.61 and 1229.0, is defined as exclusive flood control space. Within this capacity allocation, 1.218 maf of flood storage is above elevation 1221.0, which is the top of the raised spillway gates. Flood control regulations specify that once Lake Mead flood releases exceed 40,000 cfs, the releases shall be maintained at the highest rate until the reservoir drops to elevation 1221.0 feet msl. Releases may then be gradually reduced to 40,000 cfs until the prescribed seasonal storage space is available. The regulations set forth two primary criteria for flood control operations related to snowmelt: 1) preparatory reservoir space requirements, and 2) application of runoff forecasts to determine releases. In preparation for each annual season of snow accumulation and associated runoff, progressive expansion of total Colorado River system reservoir space iis r r o required during the latter half of each year. Minimum available flood control e Inte space increases from 1.5 017 f th maf on August 1 to 5.35 maf on January 1. Requiredtflood storage space can be p . o er 29, 2 . e emb accumulated within Lake Mead and in specifiedD ion v upstream reservoirs: Powell, Navajo, at Nov Blue Mesa, Flaming Gorge and Fontenelle. d onminimum required to be reserved ajo N ive The Nav exclusively for flood control storage chLake Mead is 1.5 maf. Table 3.3-2 presents the d in 64, ar in cite 1 storage space within the Colorado River system by date: amount of required flood 68 - No. 14 Table 3.3-2 Minimum Required Colorado River System Storage Space Storage Volume (maf) Date August 1 September 1 October 1 November 1 December 1 January 1 1.50 2.27 3.04 3.81 4.58 5.35 Normal space-building releases from Lake Mead to meet the required August 1 to January 1 flood control space are limited to a maximum of 28,000 cfs. Releases in any month based on water entitlement holders’ demand are much less than 28,000 cfs (on the order of 20,000 cfs or less). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 174 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Between January 1 and July 31, flood control releases, based on forecasted inflow, may be required to prevent filling of Lake Mead beyond its 1.5 maf minimum space requirement. Beginning on January 1 and continuing through July, the CBRFC issues monthly runoff forecasts. These forecasts are used by Reclamation in estimating releases from Hoover Dam. The release schedule contained in the Corps’ regulations is based on increasing releases in six steps as shown on Table 3.3-3. Table 3.3-3 Minimum Flood Control Releases at Hoover Dam Step Amount of Cubic Feet/Second Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 0 19,000 28,000 35,000 40,000 73,000 The lowest step, zero cfs, corresponds to times when the regulations do not require flood control releases. Hoover Dam releases are then made to meeterior and power t water objectives. The second step, 19,000 cfs, is based on the powerplant capacity of Parker he In 2017 of t Dam. The third step, 28,000 cfs, corresponds toDept. the Davis Dam 29, . ber Powerplant capacity. The fourth step in the Corps release schedulevis 35,000 em This flow corresponds to v cfs. ion Nat Hoover No the powerplant flow-through vajo capacity ofved onDam in 1987. However, the present i in Na powerplant flow-through capacityarch ited 6864, at Hoover Dam is 49,000 cfs. At the time Hoover c Dam was completed, 4-1 cfs was the approximate maximum flow from the dam 40,000 o. 1 N considered to be nondamaging to the downstream streambed. The 40,000 cfs flow now forms the fifth step. Releases of 40,000 cfs and greater would result from lowprobability hydrologic events. The sixth and final step in the series (73,000 cfs) is the maximum controlled release from Hoover Dam that can occur without spillway flow. Flood control releases are required when forecasted inflow exceeds downstream demands, available storage space at lakes Mead and Powell and allowable space in other Upper Basin reservoirs. This includes accounting for projected bank storage and evaporation losses at both lakes, plus net withdrawal from Lake Mead by the SNWA. The Corps regulations set the procedures for releasing the volume that cannot be impounded, as discussed above. Average monthly releases are determined early in each month and apply only to the current month. The releases are progressively revised in response to updated runoff forecasts and changing reservoir storage levels during each subsequent month throughout the January 1–July 31 runoff period. If the reservoirs are full, drawdown is accomplished to vacate flood control space as required. Unless flood control is necessary, Hoover Dam is operated to meet downstream demands. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 175 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 During non-flood operations, the end-of-month Lake Mead elevations are driven by consumptive use needs, Glen Canyon Dam releases and Treaty deliveries to Mexico. Lake Mead end-of-month target elevations are not fixed as are the end-of-month target elevations for Lake Mohave and Lake Havasu. Normally, Lake Mead elevations decline with increasing irrigation deliveries through June or later and then begin to rise again. Lake Mead’s storage capacity provides for the majority of Colorado River regulation from Glen Canyon Dam to the border with Mexico. 3.3.2 NATURAL RUNOFF AND STORAGE OF WATER Most of the natural flow in the Colorado River system originates in the Upper Basin and is highly variable from year to year. The natural flow represents an estimate of runoff flows that would exist without storage or depletion by man and was used in the modeling of the baseline conditions and interim surplus criteria alternatives. About 86 percent of the Colorado River System annual runoff originates in only 15 percent of the watershed—in the mountains of Colorado, Utah, Wyoming and New Mexico. While the average annual natural flow at Lees Ferry is calculated at 15.1 maf, annual flows in excess of 23 maf and as little as 5 maf have occurred. The flow in the Colorado River above Lake Powell reaches its annual maximum during the April through July period. During the summer and fall, thunderstorms occasionally produce additional peaks in the ior Inter 17 peaks and river. However, these flows are usually smaller in volume the the snowmelt than 20 of pGlen Canyon9Dam consist almost of much shorter duration. Flows immediately below t. e r2 , .D mbe entirely of water released from Lake Powell.vDownstream of Glen Canyon Dam, the ation on Nove o annual river gains from tributaries, N ved discharge and occasional flash floods avaj groundwater in N900,000raf. iImmediately downstream of Hoover Dam, the from side canyonsed average a ch cit almost6864, of water released from Lake Mead. Downstream of river flows consist 4-1 entirely 1 Hoover Dam, the river gains additional water from tributaries such as the Bill Williams No. River and the Gila River, groundwater discharge, and return flows. Total storage capacity in the Colorado River system is nearly four times the river’s average natural flow. The various reservoirs that provide storage in the Colorado River system and their respective capacities were discussed in Section 1.3.2. Figure 3.3-1 presents an overview of the historical natural flow calculated at Lees Ferry for calendar years 1906 through 1999. The natural flow represents an estimate of the flows that would originate or exist above Lees Ferry without storage or depletion by man. This is different than the recorded or historical stream flows that represent actual measured flows. Figure 3.3-2 presents an overview of the historical flows recorded at Lees Ferry for the period 1922 through 1999 (calendar year). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-6 1905 1910 1915 Running Average 10 Year Average Flow (maf) 1920 1925 1930 1935 1940 1945 1955 3.3-7 Year 1950 1960 1965 1970 1975 1980 1985 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5 10 An nu 15 al Flo w (m af) 20 25 Figure 3.3-1 Natural Flow at Lees Ferry Stream Gage AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 1990 1995 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 176 of 1200 0 1905 5 10 15 20 25 1910 1915 1920 1925 1930 1935 1940 1945 1955 3.3-8 Year 1950 1960 1965 1970 1975 1980 1985 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Running Average 10 Year Average Flow (maf) Figure 3.3-2 Historic Annual Flow at Lees Ferry Stream Gage COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Annual Flow (ma AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 1990 1995 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 177 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 178 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.3.3 CHAPTER 3 MODELING AND FUTURE HYDROLOGY 3.3.3.1 MODEL CONFIGURATION Future Colorado River system conditions under baseline conditions and the surplus alternatives were simulated using a computerized model. The model framework used for this process is a commercial river modeling software called RiverWare. RiverWare was developed by the University of Colorado through a cooperative process with Reclamation and the Tennessee Valley Authority. RiverWare was configured to simulate the Colorado River System and its operation and integrates the Colorado River Simulation System (CRSS) model that was developed by Reclamation in the early 1970s. River operation parameters modeled and analyzed include the water entering the river system, storage in system reservoirs, releases from storage, river flows, and the water demands of and deliveries to the Basin States and Mexico. The water supply used by the model consists of the historic record of natural flow in the river system over the 85-year period from 1906 through 1990, from 29 individual inflow points on the system. Future Colorado River water demands were based on demand and depletion projections riorthe In from 17 river less prepared by the Basin States. Depletions are defined as diversionste f the return flow credits, where applicable. Return flow credits are applied20 a portion of pt. o er 29, when e b the diverted water is returned to the riveron v. D In cases where there are no return i system. Novem at the depletion is equal to the diversion. The flow credits associated with the jo N vadiversions, d on NaCanyon chiveHoover Dam and other elements of the simulated operationd in of Glen , ar Dam, ite Colorado Rivercsystem-was864 consistent with the LROC, applicable requirements for 16 storage and flood control management, water supply deliveries to the Basin States, o. 14 N Indian tribes, and Mexico, and flow regulation downstream of the system dams. 3.3.3.2 INTERIM SURPLUS CRITERIA MODELED As discussed in Chapter 2, seven operational scenarios are considered in this FEIS. The seven scenarios considered and modeled consist of two different baseline conditions and the five surplus alternatives. The two baseline conditions are similar except that one includes the modeling of California’s intrastate water transfers while the other does not. The five surplus alternatives consist of the Basin States, Flood Control, Six States, California and the Shortage Protection alternatives. Surplus deliveries to the Lower Division states and Mexico are provided under baseline conditions and all surplus alternatives. Common to baseline conditions and all alternatives, a surplus is determined when flood control releases are made from Lake Mead. As a general modeling assumption, Mexico receives surplus deliveries only under this condition. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 179 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 As noted above, two different baseline conditions were modeled and evaluated (baseline conditions with transfers and baseline conditions without transfers). The normal schedules of the three California entities involved in the transfers (Metropolitan Water District, Imperial Irrigation District, and Coachella Water Valley District) are tabulated in Attachment H. The comparative analysis of the two baseline conditions is presented in Attachment L. The baseline conditions with transfers were selected for use in the comparative analysis of the surplus alternatives. The reason for this is a desire to maintain consistency. All of the surplus alternatives include intrastate water transfers and therefore, it was prudent to compare the baseline conditions with transfers to focus and isolate the potential impacts of the interim surplus criteria from that of transfers. 3.3.3.3 GENERAL MODELING ASSUMPTIONS Definitions and descriptions of the baseline conditions and the surplus alternatives and their operational criteria were provided in Chapter 2. The modeling of river system operations for the analysis presented in this FEIS also required certain assumptions about various aspects of water delivery and system operation. Some important modeling assumptions are listed below. Other modeling details and assumptions are presented in Attachment J. ior Inter 17 Assumptions Common to Baseline and All Alternatives:the 20 of ept. ber 29, v. D v m • The current Upper Basin reservoir operating rules are equivalent under all ation conditions.e No surplus alternatives andjo N va the baseline on ed chiv in Na • The Lake Mead flood4, ar procedures are always in effect. ited 686 control c -1 • Reservoir starting conditions (all system reservoirs) are based on projected water o. 14 N level elevations for January 1, 2002. Reclamation’s 24 month study model (also a model implemented in RiverWare) was used to project these elevations, using actual elevations as of August 2000 and projected operations for the 2001 water year. • The Upper Basin States' depletion projections are as provided by the Upper Colorado River Commission (December 1999) and subsequently modified to include new Indian tribe schedules provided during the preparation of the DEIS. (See Attachments K and Q.) • Water deliveries to Mexico are pursuant to the requirements of the Treaty. This provides minimum annual deliveries of 1.5 maf to Mexico and up to 1.7 maf under Lake Mead flood control release conditions. • Mexico’s principal diversion is at Morelos Dam where most of its Colorado River apportionment of 1.5 maf is diverted. In practice, up to 140 thousand acrefeet (kaf) is delivered to Mexico near the Southerly International Boundary (SIB). The model, however, extends to just south of the Northerly International Boundary (NIB) to include the diversion at Morelos Dam and accounts for the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 180 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 entire Treaty delivery at that point. Under normal conditions, the model sets the diversion and depletion schedule for the Mexican Treaty delivery at Morelos Dam to 1.515 mafy. The additional 15,000 af accounts for typical scheduling errors and over-deliveries. • The modeled Colorado River water deliveries under the baseline conditions and surplus alternatives assumed that all Arizona shortages would be absorbed by the Central Arizona Project. Reclamation acknowledges that under the current priority framework, there would be some sharing of Arizona shortage between the Central Arizona Project and other Priority 4 users. However, the bases or formula for the sharing of Arizona shortages is the subject of current negotiations and as such, could not be adequately modeled for the FEIS. The water supply conditions modeled for the FEIS were used to evaluate the relative differences in water deliveries to each state under baseline conditions and the surplus alternatives. The normal, surplus and shortage condition water depletion schedules modeled in the FEIS are consistent with the depletion schedules prepared by the Basin states for this purpose. • For the modeling presented in the FEIS, the Yuma Desalting Plant depletion schedule for bypass to Mexico was set to 120,000 acre-feet per year (afy) from or 2002-2021, representing the water provided by the U.S. to teriCienega. For In the Treaty delivery. modeling purposes, this depletion is not counted astpart of the2017 f he pt. o 2022, 9, 2 The desalting plant is assumed to operate e v. D beginning er reducing the bypass to n purposes,vemb 52,000 afy. Similarly, for modeling atio on No this depletion is not counted as ajo N should be noted that the United States recognizes v part of the Treaty delivery. Ithived n Na arc d iobligation,to replace, as appropriate, the bypass flows and the that itcitean has 864 for modeling purposes, do not necessarily represent assumptions4-16 herein, 1 made No. the policy that Reclamation will adopt for replacement of bypass flows. The assumptions made with respect to modeling the bypass flows are intended only to provide a thorough and comprehensive accounting of Lower Basin water supply. The United States is exploring options for replacement of the bypass flows, including options that would not require operation of the Yuma Desalting Plant. • Lake Mead is operated to meet depletion schedules provided by the Lower Division states, Indian tribes, and Mexico. (See Attachments H and Q.) • Lake Mohave and Lake Havasu are operated in accordance with their existing rule curves. • The water supply conditions modeled under the surplus alternatives and baseline conditions considered the intrastate water transfers being planned by California. • There are no established shortage criteria that define when Lower Basin water users would receive shortage condition deliveries. However, the model is configured to provide approximately an 80 percent protection for Lake Mead water elevation of 1083 feet msl (minimum power generation elevation). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 181 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Assumptions Specific to Surplus Alternatives: • The respective surplus criteria for the surplus alternatives are assumed to be effective for a specified period of 15 years. The effective period that was modeled is defined as the 15-year period beginning on January 1, 2002 and ending December 31, 2016. At the conclusion of the 15-year period, the modeled operating criteria for each of the surplus alternatives is assumed to revert to the operating criteria used to model baseline conditions (baseline conditions with transfers). • The surplus depletion schedules for Arizona, California and Nevada vary under each surplus alternative and the baseline conditions and are presented in Attachment H. 3.3.3.4 LAKE MEAD WATER LEVEL PROTECTION ASSUMPTIONS There are no established shortage criteria for the operation of Lake Mead. However, it was necessary to include some shortage criteria in the model simulation to address concerns related to low Lake Mead water levels. Three important Lake Mead water elevations were selected for analysis. The significance of these selected elevations r relates to known economic and/or socioeconomic impacts that wouldroccur if Lake te io InElevation 1083 feet e Mead water levels were lowered below the selected waterf levels. o th 29, 2017 msl is the minimum water level for effective power pt. generationrat the Hoover . De Elevation 1050 feet msl is the be Powerplant based on its existing turbineion v configuration. em at Nov upper water intake. Water o operation onSNWA's minimum water level necessary jforN of Nava throughivedintake is delivered to Las Vegas Valley, in Mead , arch this withdrawn from thed Lake 4 cite 168 of Boulder City and other-parts 6 Clark County. Even though SNWA has constructed a 4 1 second intake No.lower elevation, the original intake at elevation 1050 feet msl is at a needed to meet full SNWA summer diversions. Elevation 1000 feet msl is the minimum water level necessary for operation of SNWA’s lower water intake. In the absence of specific shortage criteria, the Lake Mead level protection assumptions listed below were applied by the model to facilitate the evaluation of the baseline conditions and surplus alternatives. First Level Shortage: • The Lake Mead water level of 1083 feet msl was designated as a level that should be protected. Operation simulations were performed to develop a “protection line” to prevent the water level from declining below elevation 1083 feet msl with approximately an 80 percent probability (see Section 3.3.4.1). The use of an alternative 1050-foot protection line is discussed in Attachment M. • A shortage would be determined to exist when the Lake Mead water level dropped below the protection line for elevation 1083 feet msl. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 182 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES • CHAPTER 3 During first level shortage conditions, the annual water delivery to CAP was set to 1.0 maf, and the SNWA was assigned four percent of the total shortage. Second Level Shortage: • A second level shortage would be determined to exist when the Lake Mead water surface elevation declined to 1000 feet msl. • During second level shortage conditions, the CAP and SNWA consumptive use would be reduced as needed to maintain the Lake Mead water level at 1000 feet msl. Once the delivery to the CAP is reduced to zero, deliveries to MWD and to Mexico would be reduced to maintain the Lake Mead water level at 1000 feet msl. Such reductions to MWD and Mexico did not occur in the simulations conducted as part of this FEIS. 3.3.3.5 COMPUTATIONAL PROCEDURES The model was used to simulate the future state of the Colorado River system on a monthly basis, in terms of reservoir levels, releases from the dams, hydroelectric energy generation, flows at various points along the system and diversions to and return flows from various water users. The input data for the model included the monthly tributary ior Inter rates for each inflows, various physical process parameters (such as the evaporation 17 0 f the reservoir) and the diversion and depletion schedules foro pt. entities in9, 2 e r 2 the Basin States and be v. D Mexico. The common and specific operating criteria vemalso input for each ation on Nowere N alternative being studied. vajo ed in Na rchiv ited in6864, a criteria for the baseline conditions and each c Despite the differences-1 the operating 14 surplus alternative, the future state of the Colorado River system (i.e., water levels at No. Lake Mead and Lake Powell) is most sensitive to the future inflows. As discussed in Section 3.3.2, observations over the period of historical record (1906–present) show that inflow into the system has been highly variable from year to year. Predictions of the future inflows, particularly for long-range studies, are highly uncertain. Although the model does not predict future inflows, it can be used to analyze a range of possible future inflows and to quantify the probability of particular events (i.e., lake levels being below or above certain levels). Several methods are available for ascertaining the range of possible future inflows. On the Colorado River, a particular technique (called the Indexed Sequential Method) has been used since the early 1980s and involves a series of simulations, each applying a different future inflow scenario (USBR, 1985; Ouarda, et al., 1997). Each future inflow scenario is generated from the historical natural flow record by “cycling” through that record. For example, the first simulation assumes that the inflows for 2002 through 2050 will be the 1906 through 1954 record, the second simulation assumes the inflows for 2002 through 2050 will be the 1907 through 1955 record, and so on. As the method progresses, the historical record is assumed to “wrap-around” (i.e., after 1990, the record reverts back to 1906), yielding a possible 85 different inflow scenarios. The COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 183 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 result of the Indexed Sequential Method is a set of 85 separate simulations (referred to as “traces”) for each operating criterion that is analyzed. This enables an evaluation of the respective criteria over a broad range of possible future hydrologic conditions using standard statistical techniques, discussed in Section 3.3.3.6. 3.3.3.6 POST-PROCESSING AND DATA INTERPRETATION PROCEDURES The various environmental and socioeconomic analyses in this FEIS required the sorting and arranging of various types of model output data into tabulations or plots of specific operational conditions, or parameters, at various points on the system. This was done through the use of statistical methods and other numerical analyses. The model generates data on a monthly time step for some 300 points (or nodes) on the river system. Furthermore, through the use of the Indexed Sequential Method, the model generates 85 possible outcomes for each node for each month over the time period 2002 through 2050. These very large data sets are generated for each surplus alternative and baseline conditions and can be visualized as three-dimensional data “cubes” with the axes of time, space (or node) and trace (or outcome for each future hydrology). The data are typically aggregated to reduce the volume of data and to facilitate comparing the alternatives to baseline conditions and to each or eri other. The type of aggregation varies depending upon the needs of the particularInt resource analysis. The 017 f the categories: those that post-processing techniques used for this FEIS fall ept.two basic29, 2 into o .D ber aggregate in time, space or both, and those that aggregate the 85 possible outcomes. vem ion v t o N Na vajo simpleed on For aggregation in time anda in N space, rchiv techniques are employed. For example, ited River 64, ato all California diversion nodes in the model are c deliveries of Colorado -168 water summed to produce14 total delivery to the state for each calendar year. Similarly, lake No. the elevations may be chosen on an annual basis (i.e., end of December) to show long-term lake level trends as opposed to short-term fluctuations. Since the interim criteria period is 2002 through 2016, some analyses may suggest aggregating over that period of time and comparing the aggregation over the remaining years (2017 through 2050). The particular aggregation used will be noted in the methodology section for each resource. Once the appropriate temporal and spatial aggregation is chosen, standard statistical techniques are used to analyze the 85 possible outcomes for a fixed time. Statistics that may be generated include the mean and standard deviation. However, the most common technique simply ranks the outcomes at each time (from highest to lowest) and uses the ranked outcomes to compute other statistics of interest. For example, if end-ofcalendar year Lake Mead elevations are ranked for each year, the median outcome for a given year is the elevation for which half of the values are below and half are above (the median value or the 50th percentile value). Similarly, the elevation for which 10 percent of the values are less than or equal to, is the 10th percentile outcome. Several presentations of the ranked data are then possible. A graph (or table) may be produced that compares the 90th percentile, 50th percentile, and 10th percentile outcomes COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-14 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 184 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 from 2002 through 2050 for the baseline and all alternatives. It should be noted that a statistic such as the 10th percentile is not the result of any one hydrologic trace (i.e., no historical sequence produced the 10th percentile). 3.3.4 MODELING RESULTS This section presents general and specific discussions of the Colorado River System operation modeling results. The following sequence of topics is used to address the potentially affected river system components: • Lake Powell water levels, • River flows between Glen Canyon Dam and Lake Mead, • Lake Mead water levels, and • River flows below Hoover Dam. As noted previously, the potentially affected portion of the Colorado River system extends from Lake Powell to the SIB. Although lakes Mohave and Havasu are within the potentially affected area, it has been determined that the interim surplus criteria ior would have no effect on the operation of these facilities. The operation of lakes Inter 17 Mohave and Havasu is pursuant to monthly operating . of the that t target elevations 0 are used to 29, 2 manage the storage and release of water and v. Dep power productionrat these facilities. Under mbe the respective target elevations, the Natiolevel n Nove is approximately 14 feet for water n fluctuation vajo feet d Lake Havasu. Under all future operating Lake Mohave and approximately fourhiveforo c in Na 4FEIS, lakes Mohave and Havasu would continue to be scenarios considered under 86 , ar cited 16 this operated under the current respective monthly target elevations. . 14- No 3.3.4.1 GENERAL OBSERVATIONS CONCERNING MODELING RESULTS Some changes to the modeling assumptions were anticipated in the DEIS and were made for the FEIS as noted in Section 3.3.3.3. These changes included the following: • updating the initial conditions to reflect the current state of the system; • updating the depletion schedules for all of the Basin States, including the Indian tribes; • changing the baseline operation from 75R to 70R (as described in Section 2.2.5); and • updating the shortage protection triggers to incorporate the new Upper Basin depletion schedules. The general effects of these changes are described below: • For the DEIS, the simulation model was run from 2000 through 2050, using the historical reservoir contents as of January 1, 2000, for the initial COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-15 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 185 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 conditions. For the FEIS, the model was run from 2002 through 2050, using forecasted reservoir contents for January 1, 2002. The forecast was obtained from Reclamation’s operations model (the “24-month Study Model”), run in September, 2000. Due to the relatively low inflow observed for the 2000 water year (approximately 75 percent of normal or about 11.4 maf of natural inflow to Lake Powell), the total initial system storage decreased approximately 4.129 maf. This amounted to decreases in initial elevations of 3.5 feet and 26.0 feet at lakes Powell and Mead, respectively. The change in initial conditions affects the results of the first few years of the simulations, and then is negligible (after about 2005). • Upper Division depletion schedules were updated to those submitted by the Upper Colorado River Commission (December, 1999), and subsequently modified to include updated Indian tribes schedules as provided by the Ten Tribes Partnership. The updated depletion schedules for the Indian Tribes and the Upper Division totals are detailed in Attachments “Q” and “K”. The total increase in Upper Division scheduled depletions ranged from two to eight percent in any given year, with an average over all years of about five percent. The largest increases are in the early years (eight percent increases in years 2005 through 2010; 6.6 percent in 2016). In general, lakes Powell and Mead rior baseline Int under 7 show a more rapid decline (observed in the 50th percentilee 1 the conditions) due to the increased demand eptheof in t. early years., 20 r 29 Recovery of Lake Powell after the interim periodion v. more rapid ase increased depletions is also D mb ov 602(a)the at Nthe e N tend to turn off equalization earlier due to storage provision. The on vajo Nathesearchived is that lakes Mead and Powell stabilize at long-term d in of effect , depletions e 2050 cit 12.56865.5 feet, respectively, below the levels shown in the about -1 and 4 4 DEIS. o. 1 N • Lower Division normal depletion schedules were updated to incorporate the new Indian tribe demands and remain at each states’ apportionment. Surplus depletion schedules were also updated for each alternative as provided by the entities involved and is detailed in Attachment H. The California alternative tends to be more liberal in the FEIS compared to the DEIS with regard to surplus deliveries and is now closer to the results of the Shortage Protection Alternative. • As discussed in Section 2.2.5, the baseline surplus strategy was changed from 75R to 70R, which changes the inflow assumption used when computing the system space available. As discussed in the DEIS, the change has a negligible effect upon the baseline results. • The shortage protection triggers were re-computed to account for the new Upper Basin depletion schedules and to investigate the issues of protecting a specified lake level with a specified degree of assurance. To ensure statistical independence, stochastically generated natural inflows above Powell were used in the study. The study used the CRSSez model and the procedure is COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-16 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 186 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 documented in the CRSSez User’s Manual (USBR, May 1988). The new triggers resulted in approximately 73 percent assurance of protecting Lake Mead elevation 1083 through the year 2040, although after 2040, the assurance level tails off rapidly (to less than 60 percent in 2050). The validity of the comparisons between surplus alternatives, however, is not compromised since all of the modeled conditions use the same shortage protection assumptions. The following general observations apply to the overall modeling and analyses results: • Future water levels of Lakes Powell and Mead will probably be lower than historical levels due to increasing Upper Basin depletions under the baseline conditions and the surplus alternatives. Of the five surplus alternatives, the Flood Control Alternative and baseline conditions were shown to have the least tendency to reduce reservoir water levels. The Shortage Protection and California alternatives were shown to have the highest tendency to reduce reservoir water levels. The results of the Six States and Basin States alternatives are similar and fall between those of the baseline conditions and the Shortage Protection and California alternatives. • Median Lake Mead elevations decline throughout the periodiofr analysis for the ter o baseline conditions and the surplus alternatives because Lower 17 he In 20 Division of t 9, depletions exceed long-term inflow. .Median. Lake Powell elevations decline ept D ber 2 v vem for a number of years and thenion Nat stabilize forothe baseline conditions as well as n N in Lake Powell elevations for the all surplus alternatives.jo va The declining trend ed o in Na and allrchiv alternatives is due to increasing Upper a surplus baselineted ci conditions 64, the Six State, Basin States, California, and Shortage 168 For Division depletions. 14No. Protection alternatives, the decline is more pronounced due to Lower Basin surplus deliveries and associated equalization releases from Lake Powell. Lake Powell elevations eventually stabilize under the baseline conditions and all alternatives. This behavior is caused by less frequent equalization releases from Lake Powell (due to the 602(a) storage requirement) as the Upper Division states continue to increase their use of Colorado River water. • A comparative analysis of the baseline conditions with and without California intrastate transfers was conducted to assess the differences between these two modeled conditions. The modeling of the two baseline conditions yielded similar results with two exceptions. The first difference was in the water deliveries to the individual California agencies participating in the water transfers. The second difference is reduced river flow (about 200,000 to 300,000 afy) below Parker Dam associated with change in delivery points resulting from the water transfers. A summary of this comparative analysis is presented in Attachment L. • To test the sensitivity of the results to the use of a 1083-foot shortage protection level, model runs were also conducted with a protection level of COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-17 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 187 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 1050 feet msl. With the 1050-foot protection level, the water levels on Lake Mead in 2016 were essentially the same under the baseline condition and Flood Control Alternative; between 10 and 20 feet lower for the Shortage Protection and California alternatives; and intermediate for the Six State Alternative. Water level plots for reservoir levels using the 1050-foot Lake Mead protection level are in Attachment M. • Interim surplus criteria had no effect on Upper Basin deliveries as expected, including the Indian demands above Lake Powell. As noted in Section 3.4.4.4, the normal delivery schedules of all Upper Basin diversions would be met under most water supply conditions. Only under periods of low hydrologic inflow conditions and inadequate regulating reservoir storage capacity upstream of the diversion point, would an Upper Basin diversion be shorted. Although the model is not presently configured to track the relative priorities under those conditions, such effects are identical under baseline and all alternatives. • Under normal conditions, deliveries to the Lower Basin users are always equal to the normal depletion schedules, including those for the Indian tribes. Under shortage conditions, only CAP and SNWA share in the shortage until CAP ior Inter runs done for goes to zero (which was not observed in any of thehe f t modeling 017 , pt. oPartnership 2 the Lower Basin this FEIS). Therefore, all tribes in the DeTribe ber 29 in . 10 em nv receive their scheduled depletion, with the ov Natio d on N exception of the Cocopah Tribe which has some Arizona Priority 4 water (see Section 3.14.2). As discussed vajo e in Na 4, archiv all Arizona shortages were assigned to CAP above, itea modeling assumption, as d 6 c for this FEIS.-168 14 No. 3.3.4.2 LAKE POWELL WATER LEVELS 3.3.4.2.1 Dam and Reservoir Configuration Glen Canyon Dam is a concrete arch dam rising approximately 700 feet above the level of the Colorado River streambed. A profile of the dam is depicted on Figure 3.3-3. Except during flood conditions, the "full reservoir" water level is 3700 feet msl, corresponding to the top of the spillway gates. Under normal operating conditions, releases from Glen Canyon Dam are made through the Glen Canyon Powerplant by means of gates on the upstream face of the dam. The minimum water level at which hydropower can be generated is elevation 3490 feet msl. Releases in excess of the powerplant capacity may be made when flood conditions are caused by high runoff in the Colorado River Basin, or when needed to provide Beach/Habitat Building Flows (BHBF) downstream of the dam, as is discussed in Section 3.6. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-18 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 188 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-3 Lake Powell and Glen Canyon Dam Important Operating Elevations Elevation (feet msl) 3800 3600 3400 3200 3000 ior Inter 17 e of th 29 0 pt.operate from , 2 Glen Canyon Dam and Lake Powell were designed to . De ber a normal maximum iona v Novem water surface elevation of 3700 feet msl to minimum elevation of 3490 feet msl, the Nat d on vajo minimum for hydropower production.hDuring flood conditions, the water surface ive Na d in can64, arc3700 feet msl by raising the spillway radial gates. elevation of Lakete ci Powell 8 exceed Since first reaching 14-16 equalization storage with Lake Mead in 1974, the reservoir water No. level has fluctuated from a high of 3708 feet msl to a low of approximately 3612 feet 3.3.4.2.2 Historic Water Levels msl, as shown on Figure 3.3-4. 3.3.4.2.3 Baseline Conditions Under the baseline conditions, the water surface elevation of Lake Powell is projected to fluctuate between full level and decreasingly lower levels during the period of analysis (2002 to 2050). Figure 3.3-5 illustrates the range of water levels by three lines, labeled 90th Percentile, 50th Percentile and 10th Percentile. The 50th percentile line shows the median water level for each future year. The median water level under baseline conditions is shown to decline to approximately 3663 feet msl by 2019 and remaining at this or slightly higher levels through 2050. The 10th percentile line shows there is a 10 percent probability that the water level would drop to 3615 feet msl by 2016 and to 3553 feet msl by 2050. Generally, there is about a 20-foot difference between the annual high and low water levels at Lake Powell. It should also be noted that the Lake Powell elevations depicted in Figures 3.3-5 to 3.3-8 are for modeled lake water levels at the end-of-July. The Lake Powell water level generally reaches its seasonal high in July whereas the seasonal lows occur at the end of the year. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-19 3380 1960 3420 3460 3500 3540 3580 3620 3660 3700 3740 1965 Figure 3.3-4 Historic Lake Powell Water Levels 1970 1975 3.3-20 Year 1980 1985 1990 Annual Low W ater Level Annual High W ater Level 1995 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in Minimum4, arc Pool (3490') cite 1686 Rated Power o. 14 N Top of Spillway (3700') COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2000 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 189 of 1200 3500 2000 3520 3540 3560 3580 3600 3620 3640 3660 3680 3700 3720 2005 90th Percentile 2010 2015 2020 3.3-21 Year 2025 2030 2035 Trace 20 2040 2045 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov Trace 77 ajo N ived v in Na 4, arch cited 1686 10th Percentile Trace 47 . 14 o N 50th Percentile Figure 3.3-5 Lake Powell End-of-July Water Elevations Under Baseline Conditions th th th 90 , 50 and 10 Percentile Values and Representative Traces COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 190 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 191 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Three distinct traces were added to Figure 3.3-5 to illustrate what was actually simulated under the various traces and respective hydrologic sequences and to highlight that the 90th, 50th and 10th percentile lines do not represent actual traces, but rather the ranking of the data from the 85 traces for the conditions modeled. The traces also illustrate the variability among the different traces and that the reservoir levels could temporarily decline below the 10th percentile line. The trace identified as Trace 20 represents the hydrologic sequence that begins in year 1926. The trace identified as Trace 47 represents the hydrologic sequence that begins in year 1953. The trace identified as Trace 77 represents the hydrologic sequence that begins in year 1983. In Figure 3.3-5, the 90th and 10th percentile lines bracket the range where 80 percent of the water levels simulated for the baseline conditions occur. The highs and lows shown on the three traces would likely be temporary conditions. The reservoir level would tend to fluctuate in the range through multi-year periods of above average and below average inflows. Neither the timing of water level variations between the highs and the lows, nor the length of time the water level would remain high or low can be predicted. These events would depend on the future variation in basin runoff conditions. Figure 3.3-6 presents a comparison of the 90th, 50th and 10th percentile lines obtained for the baseline conditions to those obtained for the surplus alternatives. erior t This figure is best Intrends that result from used for comparing the relative differences in the general lakehe f t level 2017 pt. o er the simulation of the baseline conditions and surplus alternatives. 29, De b v. tion n Novem aControl Alternative is the alternative that could As illustrated in Figure 3.3-6, vajo N a the Flood ved o potentially result in thein N LakerPowell water levels. The Shortage Protection highest , a chi ted 68 Alternative are the alternatives that could potentially result 4 Alternative andci California6 the 4-1 1 in the lowest water. levels. The baseline conditions yield similar levels to those observed No under the Flood Control Alternative. The water levels observed under the California alternative are similar to those observed under the Shortage Protective Alternative. The results obtained under the Six States and Basin States alternatives are similar and fall between the Baseline and Shortage Protection alternatives. Figure 3.3-7 shows the frequency that future Lake Powell end-of-July water elevations would exceed elevation 3695 feet msl under the baseline conditions and surplus alternatives. When the Lake Powell water level is at or exceeds 3695 feet msl, the reservoir is considered to be essentially full. In year 2016, under baseline conditions, the percentage of values greater than or equal to elevation 3695 feet msl is 27 percent. In 2050, the percentage of values greater than or equal to elevation 3695 feet msl is 26 percent. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-22 3500 2000 3520 3540 3560 3580 3600 3620 3640 3660 3680 3700 3720 90th Percentile 2005 2010 2015 Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative 2020 3.3-23 Year 2025 2030 2035 2040 2045 50th ior Percentile Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc 10th Percentile cite 168 14 No. Baseline Conditions Figure 3.3-6 Lake Powell End-of-July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions th th th 90 , 50 and 10 Percentile Values COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 192 of 1200 0% 2000 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2005 2010 2015 2020 3.3-24 Year 2025 2030 2035 2040 2045 Shortage Protection Alternative ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.3-7 Lake Powell End-of-July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to Elevation 3695 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 193 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 194 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Figure 3.3-8 provides a comparison of the frequency that future Lake Powell end-of-July water elevations under baseline conditions and the surplus alternatives would be at or exceed a lake water elevation of 3612 feet msl. Lake Powell water surface elevation 3612 feet msl is used in this analysis as the low threshold elevation for marina and boat ramps at Lake Powell. This threshold elevation of 3612 feet msl is used to evaluate the baseline conditions and the effects of interim surplus criteria alternatives on shoreline facilities at Lake Powell in the Environmental Consequences section (Section 3.9.2.3.1). The lines represent the percentage of values greater than or equal to the lake water elevation of 3612 feet msl under the baseline conditions and surplus alternatives. In year 2016, under the baseline conditions, the percentage of values greater than or equal to elevation 3612 feet msl is 91 percent. In 2050, the percentage of values greater than or equal to elevation 3612 feet msl decreases to 72 percent for the baseline conditions. 3.3.4.2.4 Comparison of Surplus Alternatives to Baseline Conditions Figure 3.3-6 compared the 90th, 50th and 10th percentile water levels of the surplus alternatives to those of the baseline conditions. As discussed above, under baseline conditions, future Lake Powell water levels at the upper and lower 10th percentiles would likely be temporary and the water level would fluctuate between them in response to multi-year variations in basin runoff conditions. The sameor i would apply to th th Inter and 10th all the surplus alternatives. The 90 percentile, median (50thpercentile) 17 0 f e pt. o er 2 of 2 percentile values of the surplus alternatives are compared to those 9, the baseline e .D b conditions in Table 3.3-4. The valuesation v in this em include those for years presented Nov table o N ed on 2016 and 2050 only. avaj v in N rchi ited 6864, a Table 3.3-4 c -1 Elevations o. 14 Lake Powell End-of-July Water Baseline Conditions N Comparison of Surplus Alternatives and th th th 90 , 50 and 10 Percentile Values Year 2016 Alternative Baseline Conditions Basin States Flood Control Six States California Shortage Protection Year 2050 90th Percentile 50th Percentile 10th Percentile 90th Percentile 50th Percentile 10th Percentile 3699 3699 3699 3699 3699 3699 3665 3664 3665 3664 3660 3659 3615 3603 3615 3603 3595 3594 3699 3699 3699 3699 3699 3699 3663 3663 3665 3663 3663 3663 3553 3551 3553 3551 3551 3551 Figure 3.3-7 compared the percentage of Lake Powell elevations that exceeded 3695 feet msl for the surplus alternatives and baseline conditions. Table 3.3-5 provides a summary of that comparison for years 2016 and 2050. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-25 70% 2000 75% 80% 85% 90% 95% 100% 2005 2010 2015 2020 3.3-26 Year 2025 2030 2035 2040 Six States Alternative 2045 ior Inter 17 California Alternative the ofShortage Protection20 9, Alternative pt. . De ember 2 v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.3-8 Lake Powell End-of-July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to Elevation 3612 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 195 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 196 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.3-5 Lake Powell End-of-July Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 3695 Feet Alternative Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative Year 2016 27% 21% 27% 22% 18% 18% Year 2050 26% 26% 26% 26% 26% 26% Figure 3.3-8 compared the percentage of Lake Powell elevations that exceeded 3612 feet msl for the surplus alternatives and baseline conditions. Table 3.3-6 provides a summary of that comparison for years 2016 and 2050. Table 3.3-6 Lake Powell End-of-July Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 3612 Feet ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. 3.3.4.3 RIVER FLOWS BETWEEN LAKE POWELL AND LAKE MEAD Alternative Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative Year 2016 91% 88% 91% 88% 87% 86% Year 2050 72% 72% 72% 72% 72% 72% The river flows between Glen Canyon Dam and Lake Mead result from controlled releases from Glen Canyon Dam (Lake Powell) and include gains from tributaries in this reach of the river. Releases from Glen Canyon Dam are managed as previously discussed in Sections 3.2.1.2 and 3.3.1.1. The most significant gains from perennial streams include inflow from the Little Colorado River and Paria River. However, inflow from these streams is concentrated over very short periods of time, and on average, make up approximately two percent of the total annual flow in this reach of the river. Figure 3.3-9 provides a comparison of the relative frequency of occurrence of annual releases from Lake Powell under the baseline conditions and surplus alternatives, during the interim surplus criteria period (through 2016). Releases between 8.23 and 11.5 maf generally correspond to years where equalization releases are being made from Lake Powell. The surplus water deliveries from Lake Mead associated with the interim surplus criteria tend to increase the relative frequency of equalization during that period compared to baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-27 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 8.23 maf 8.23 to 10 maf 10 to 11.5 maf 3.3-28 Amount Released 11.5 to 13 maf 13-14.5 maf 14.5-16 maf >16 maf Shortageor i Protection Alternative Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.3-9 Histogram of Modeled Lake Powell Annual Releases (Water Years) 2002 to 2016 (85 Traces) COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Frequency of Occurrences AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 197 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 198 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.3.4.4 LAKE MEAD WATER LEVELS This section provides a general description of Hoover Dam and Lake Mead, discusses historic Lake Mead water levels and summarizes the results of the future Lake Mead water level simulations under baseline conditions and the surplus alternatives. 3.3.4.4.1 Dam and Reservoir Configuration Hoover Dam and Lake Mead are operated with the following three main priorities: 1) river regulation, improvement of navigation, and flood control, 2) irrigation and domestic uses, including the satisfaction of present perfected water rights, and 3) power. The Boulder Canyon Project Act of 1928 specified flood control as the project purpose having first priority for operation of Hoover Dam and Lake Mead. Hoover Dam is the northernmost Reclamation facility on the lower Colorado River and is located 326 miles downstream of Lee Ferry. Hoover Dam provides flood control protection and Lake Mead provides the majority of the storage capacity for the Lower Basin as well as significant recreation opportunities. Lake Mead storage capacity is 27.38 maf at a maximum water surface elevation of 1229.0 feet msl. At this elevation, Lake Mead’s water surface area would equal 163,000 acres. The dam’s r rio four intake towers draw water from the reservoir at elevations above 895 e Into drive 7 generators feet te 17 h . of t r 29, 201 within the dam’s powerplant. The minimum water surface elevation for effective power t Dep mbe generation is 1083 feet msl. n v. ve io Nat d n No vajo Meadvwereoestablished to manage potential flood Flood control regulationsNa Lake rchi e in for 4, a ited and snowmelt. Lake Mead’s uppermost 1.5 maf of storage c events arising from rain 686 -1 capacity, between .elevations 1219.61 and 1229.0 feet, is defined as exclusive flood o 14 N control. Within this capacity allocation, 1.218 maf of flood storage is above elevation 1221.0 feet, the top of the raised spillway gates. Figure 3.3-10 illustrates some of the important Hoover Dam and Lake Mead water surface elevations that are referenced in subsequent sections. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-29 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 199 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-10 Lake Mead and Hoover Dam Important Operating Elevations INTAKE TOWERS 1400 TOP OF DAM EL. 1232 SPILLWAY Elevation (feet msl) 1200 POWER HOUSE 1000 800 PENSTOCK 600 400 ior Inter 17 f the 9 0 pt. o erand , 2 Lake Mead usually is at its maximum water level in November 2 December. If . De b o achieved between iis n v Novem August 1 to January 1. at required, system storage space-building on jo N Hoover Dam storage space-building chived are limited to 28,000 cfs, while the mean Nava ar releases in daily releases to imeet the water delivery orders of Colorado River water entitlement c ted 16864, holders normally range-between 8000 cfs to 18,000 cfs. 14 No. In addition to controlled releases from Lake Mead to meet water supply and power requirements, water is also diverted from Lake Mead at the SNWA Saddle Island intake facilities, Boulder City’s Hoover Dam intake, and the Basic Management, Inc.’s (BMI) intake facility for use in the Las Vegas area for domestic purposes by SNWA, BMI and other users. The diversions by SNWA at its Saddle Island intake facilities entail pumping the water from the intake to SNWA’s transmission facilities for treatment and further conveyance to the Las Vegas area. The elevation of the original SNWA intake is approximately 1000 feet msl. However, the minimum required Lake Mead water level necessary to operate the pumping units at SNWA’s original intake facility is 1050 feet msl. SNWA recently constructed a second pumping plant with an intake elevation of 950 feet msl. The minimum required Lake Mead water level necessary to operate the pumping units at SNWA’s second intake facility is 1000 feet msl. The new SNWA intake provides only a portion of the capacity required by SNWA to meet its Lake Mead water supply needs. Therefore, the intake elevation of SNWA’s original pumping plant is critical to its ability to divert its full Colorado River water entitlement. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-30 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 200 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.3.4.4.2 Historic Lake Mead Water Levels Figure 3.3-11 presents an overview of the historic annual water levels (annual maximum and minimum) of Lake Mead. As noted in Figure 3.3-11, the annual change in elevations of Lake Mead has ranged from less than ten feet to as much as 75 feet msl. The decrease in the range of the elevations within a year observed after the mid-1960s can be attributed to the regulation provided by Lake Powell. Historic Lake Mead low water levels have dropped to the minimum rated power elevation (1083 feet msl) of the Hoover Powerplant during two periods (1954 to 1957 and 1965 to 1966). The maximum Lake Mead water surface elevation of approximately 1225.6 feet msl occurred once, in 1983. Three Lake Mead water surface elevations of interest are shown in Figure 3.3-11. The first elevation is 1221 feet msl, the top of the spillway gates. The second elevation is 1083 feet msl, the minimum elevation for the effective generation of power. The third elevation is 1050 feet msl, the minimum elevation required for the operation of SNWA’s original intake facility. ior Inter 17 f the Under the baseline conditions, the water surface elevation of Lake9, 20 is projected to pt. o er 2 Mead e b fluctuate between full level and decreasinglyv. D levels during the period of analysis lower ion rangeNovem levels (end of December) at the on of water (2002 to 2050). Figure 3.3-12 illustrates jo N d Nava arc 50th Percentile and 10th Percentile. The 50th by three lines, labeled i90th Percentile, hive n d the median, water level for each future year. The median water cite 16864 percentile line shows level under baseline14 is No. conditionsth shown to decline to 1162 feet msl by 2016 and to 3.3.4.4.3 Baseline Conditions 1111 feet msl by 2050. The 10 percentile line shows there is a 10 percent probability that the water level would decline to 1093 feet msl by 2016 and to 1010 feet msl by 2050. It should also be noted that the Lake Mead elevations depicted in Figure 3.3-12 represent water levels at the end of December which is when lake levels are at a seasonal high. Conversely, the Lake Mead water level generally reaches its annual low in July. Three distinct traces are added to Figure 3.3-12 to illustrate what was actually simulated under the various traces and respective hydrologic sequences and to highlight that the 90th, 50th and 10th percentile lines do not represent actual traces, but rather the ranking of the data from the 85 traces for the conditions modeled. The three traces illustrate the variability among the different traces and that the reservoir levels could temporarily decline below the 10th percentile line. The trace identified as Trace 20 represents the hydrologic sequence that begins in year 1926. The trace identified as Trace 47 represents the hydrologic sequence that begins in year 1953. The trace identified as Trace 77 represents the hydrologic sequence that begins in year 1983. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-31 660 700 740 780 820 860 900 940 980 1020 1060 1100 1140 1180 1220 1260 1935 1940 1945 1950 1955 1960 1970 Year 3.3-32 1965 1975 1980 1985 1990 Minimum SNWA Intake Elevation (1050') Minimum Rated Power Pool (1083') Top of Spillway (1221') Figure 3.3-11 Historic Lake Mead Water Levels (Annual Highs and Lows) ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc Annual High Water Level cite 168 Annual Low Water Level o. 14 N COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 1995 2000 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 201 of 1200 1000 2000 1020 1040 1060 1080 1100 1120 1140 1160 1180 1200 1220 1240 90th Percentile 2005 2010 2015 2020 3.3-33 Year 2025 2030 2035 2040 2045 ior Inter 17 Trace 77 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc 10th Percentile cite 168 Trace 47Trace 20 o. 14 N 50th Percentile Figure 3.3-12 Lake Mead End-of-December Water Elevations Under Baseline Conditions th th th 90 , 50 and 10 Percentile Values and Representative Traces COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 202 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 203 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 In Figure 3.3-12, the 90th and 10th percentile lines bracket the range where 80 percent of future Lake Mead water levels simulated for the baseline conditions occur. The highs and lows shown on the three traces would likely be temporary conditions. The reservoir level would tend to fluctuate through multi-year periods of above average and below average inflows. Neither the timing of water level variations between the highs and the lows, nor the length of time the water level would remain high or low can be predicted. These events would depend on the future variation in basin runoff conditions. Figure 3.3-13 presents a comparison of the 90th, 50th and 10th percentile lines obtained for the baseline conditions to those obtained for the surplus alternatives. This figure is best used for comparing the relative differences in the general lake level trends that result from the simulation of the baseline conditions and surplus alternatives. As illustrated in Figure 3.3-13, the Flood Control Alternative is the alternative that could potentially result in the highest Lake Mead water levels. The California Alternative is the alternative that could potentially result in the lowest water levels. The water levels observed under the Shortage Protection Alternative are similar to those of the California Alternative with some years slightly lower. The baseline conditions yield slightly lower levels than the Flood Control Alternative, but the differences are very small. The results obtained under the Six States and Basin States alternatives are similarerior between the and fall Int Flood Control and Shortage Protection alternatives. 017 f the pt. o 29, 2 . De that mberLake Mead end of Figure 3.3-14 provides a comparison of the n v frequency e future N Natioconditions ov the surplus alternatives would be December water elevations under o vaj baseline ed on and v at or exceed a lake water elevation archi feet msl. The lines represent the percentage of of 1200 in Na ited equal 864, lake water elevation of 1200 feet msl under the baseline c values greater than or -16 to the 4 conditions andNo. 1 alternatives. In year 2016, under the baseline conditions, the surplus percentage of values greater than or equal to elevation 1200 feet msl is 22 percent. In 2050, the percentage of values greater than or equal to elevation 1200 feet msl decreases to 14 percent for the baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-34 1000 2000 1020 1040 1060 1080 1100 1120 1140 1160 1180 1200 1220 2005 2010 2015 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 2020 3.3-35 Year 2025 2030 2035 2040 10th Percentile ior Inter 17 e of th 29, 20 pt. . De ember 50th Percentile v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N 2045 90th Percentile Figure 3.3-13 Lake Mead End-of-December Water Elevations th th th Comparison of Surplus Alternatives and Baseline Conditions 90 , 50 and 10 Percentile Values COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 204 of 1200 0% 2000 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 2005 2010 2015 2020 3.3-36 Year 2025 2030 2035 2040 2045 California Alternative r terio InShortage Protection Alternative e of th 29, 2017 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions 3.3-14 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1200 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 205 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 206 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-15 provides a comparison of the frequency that future Lake Mead end of December water elevations would be at or exceed a lake water elevation of 1083 feet msl under baseline conditions and the surplus alternatives. In year 2016, under the baseline conditions, the percentage of values greater than or equal to elevation 1083 feet msl is 93 percent. In 2050, the percentage of values greater than or equal to elevation 1083 feet msl decreases to 58 percent for the baseline conditions. Figure 3.3-16 provides a comparison of the frequency that future Lake Mead end of December water elevations under baseline conditions and the surplus alternatives would be at or exceed a lake water elevation of 1050 feet msl. In year 2016, under the baseline conditions, the percentage of values greater than or equal to elevation 1050 feet msl is 100 percent. In 2050, the percentage of values greater than or equal to elevation 1050 feet msl decreases to 75 percent for the baseline conditions. Figure 3.3-17 provides a comparison of the frequency that future Lake Mead end of December water elevations under baseline conditions and the surplus alternatives would be at or exceed a lake water elevation of 1000 feet msl. In year 2016, under the baseline conditions, the percentage of values greater than or equal to elevation 1000 feet msl is 100 percent. In 2050, the percentage of values greater than or equal to elevation 1000 feet msl decreases to 99 percent for the baseline conditions. erior Int f the 9, 2017 3.3.4.4.4 Comparison of Surplus Alternatives topt. o Baseline Conditions 2 v De vember n th . tio o th Figure 3.3-13 compared the 90ajo Na 10 on N , 50th and d percentile water levels of the surplus v e alternatives to thosed in Nbaseline rchiv of the a , a conditions. As discussed above, under baseline ite Mead water levels at the upper and lower 10th percentiles would c conditions, future Lake-16864 likely be temporary14 the water levels are expected to fluctuate between them in No. and response to multi-year variations in basin runoff conditions. The same would apply to all the surplus alternatives. The 90th percentile, median (50th percentile) and 10th percentile values of the surplus alternatives are compared to those of the baseline conditions in Table 3.3-7. The values presented in this table include those for years 2016 and 2050 only. Table 3.3-7 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions th 90 , 50th and 10th Percentile Values Year 2016 Alternative Baseline Conditions Basin States Flood Control Six States California Shortage Protection Year 2050 90th Percentile 50th Percentile 10th Percentile 90th Percentile 50th Percentile 10th Percentile 1215 1215 1215 1215 1208 1208 1162 1143 1162 1146 1131 1130 1093 1082 1095 1084 1071 1077 1209 1209 1210 1210 1209 1209 1111 1111 1111 1111 1111 1111 1010 1007 1010 1008 1003 1005 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-37 50% 2000 55% 60% 65% 70% 75% 80% 85% 90% 95% 100% 2005 2010 2015 2020 3.3-38 Year 2025 2030 2035 2040 2045 California Alternative r terio InShortage Protection Alternative e of th 29, 2017 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.3-15 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1083 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 207 of 1200 70% 2000 75% 80% 85% 90% 95% 100% Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions 2005 2010 2015 2020 3.3-39 Year 2025 2030 2035 2040 2045 2050 CHAPTER 3 California Alternative r terio Protection Alternative In Shortage 7 e of th 29, 201 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Figure 3.3-16 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1050 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 208 of 1200 90% 2000 91% 92% 93% 94% 95% 96% 97% 98% 99% 100% 2005 2010 2015 2020 3.3-40 Year 2025 2030 2035 2040 Six States Alternative Flood Control Alternative 2045 ior Inter 17 e 0 of th California,Alternative 29 2 ept. beShortage Protection Alternative r D n v. em tio ov jo Na ved on N Nava archi in cited 16864, o. 14 N Basin States Alternative Baseline Conditions Figure 3.3-17 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1000 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 209 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 210 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-14 compared the percentage of Lake Mead elevations that exceeded 1200 feet msl for the surplus alternatives and baseline conditions. Table 3.3-8 provides a summary of that comparison for years 2016 and 2050. Table 3.3-8 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1200 Feet Alternative Baseline Conditions Basin States Flood Control Six States California Shortage Protection Year 2016 22% 19% 22% 19% 14% 16% Year 2050 14% 14% 16% 15% 14% 14% Figure 3.3-15 compared the percentage of Lake Mead elevations that exceeded 1083 feet msl for the surplus alternatives and baseline conditions. Table 3.3-9 provides a summary of that comparison for years 2015 and 2050. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation Year 2016 ve No Alternative Year 2050 jo N ved on Baseline Conditions ava 93% 58% i N h Basin States in 89% 58% d , arc 4 cite Flood Control -1686 94% 59% Six States. 14 89% 58% No California 87% 59% Table 3.3-9 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1083 Feet Shortage Protection 87% 58% Figure 3.3-16 compared the percentage of Lake Mead elevations that exceeded 1050 feet msl for the surplus alternatives and baseline conditions. Table 3.3-10 provides a summary of that comparison for years 2016 and 2050. Table 3.3-10 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1050 Feet Alternative Baseline Conditions Basin States Flood Control Six States California Shortage Protection Year 2016 100% 99% 100% 99% 95% 98% COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-41 Year 2050 75% 75% 75% 75% 75% 75% Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 211 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-17 compared the percentage of Lake Mead elevations that exceeded 1000 feet msl for the surplus alternatives and baseline conditions. Table 3.3-11 provides a summary of that comparison for years 2016 and 2050. Table 3.3-11 Lake Mead End-of-December Water Elevations Comparison of Surplus Alternatives and Baseline Conditions Percentage of Values Greater than or Equal to Elevation 1000 Feet Alternative Baseline Conditions Basin States Flood Control Six States California Shortage Protection Year 2016 100% 100% 100% 100% 100% 100% Year 2050 99% 99% 99% 99% 92% 99% 3.3.4.5 COMPARISON OF RIVER FLOWS BELOW HOOVER DAM This section describes results of the analysis of the simulated Colorado River flows below Hoover Dam. The model of the Colorado River system was used to simulate future mean monthly flows under baseline conditions and the surplusralternatives. Four ior Inte river reaches specific river locations were selected to represent flows within selected017 f the below Hoover Dam. The river reaches and corresponding flow locations are listed in pt. o er 29, 2 . De Table 3.3-12 and are shown graphically ion Map 3.3-1. emb on v ov at N N vajo hived on Na d in 64, arc Table 3.3-12 iteColorado8River Flow Locations Identified for Evaluation c -16 o. 14 Selected River Flow Locations N Colorado River Reach Description ween Hoover Dam and Parker Dam ween Parker Dam and Palo Verde Diversion Dam ween Palo Verde Diversion and Imperial Dam ween Imperial Dam and SIB 1 vasu National Wildlife Refuge (NWR) Approximate 1 River Mile 242.3 stream of Colorado River Indian Reservation 180.8 wnstream of the Palo Verde Diversion Dam ow the Mexico Diversion at Morelos Dam 133.8 23.1 River miles as measured from the southerly international border with Mexico Two types of analysis of the potential of interim surplus criteria to affect river flows were conducted. In the first analysis, the potential effects on the total annual volume of flow in each reach were evaluated. In this analysis, the mean monthly flows were first summed over each calendar year. The 90th, 50th, and 10th percentiles of the annual volumes were then computed for each year. Plots of these percentiles for baseline COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-42 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 212 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 conditions and all surplus alternatives are included in this section for each of the four river points. Cumulative distributions of the annual flow volumes are also presented for specific years to aid in the understanding of the effects. These cumulative distributions consider the year 2006, the year when the largest effects at the 90th percentile are seen. The second analysis investigated the potential effects on seasonal flows. Cumulative distributions of mean monthly flows (in cfs) were produced for specific years and selected months representative of each season. The mean monthly flows for January were used to represent the winter season flows and likewise for April, July, and October to represent spring, summer, and fall, respectively. The specific years analyzed included 2006, 2016, 2025, and 2050. Only the graphs for 2016 are presented in this section. The graphs for the other years are presented in Attachment N. It should be noted that the monthly demand schedules used in the model are based on a distribution of the total annual demand (a percentage for each month). Although each diversion point may use a different distribution, those percentages do not change from year to year, and can not reflect potential future changes in the system that might affect the monthly distributions. Therefore, the seasonal differences are primarily governed by the overall changes in annual flow volumes, coupled with the effect of each diversion’s distribution upstream of the point of interest. erior Int f the 9, 2017 o Daily and hourly releases from Hoover Dam reflectpt. short-term demands of Colorado 2 . De theembermanagement in Lakes nv River water users with diversions located downstream, storage atio Nov Mohave and Havasu, and powerjo N ved on a production at Hoover, Davis and Parker Dams. The av i close proximity ofed in Mohave to rch Lake N 4, a Hoover Dam effectively dampens the short-term it c 6 6 fluctuations below Hoover 8 14-1 Dam. The scheduling and subsequent release of water . Parker Dams create short-term fluctuations in river flows, depths, through DavisNo and and water surface elevations downstream of these structures. These fluctuations of water surface elevations in the river are most noticeable in the river reaches located immediately downstream of the dams and lessen as the downstream distance increases. Interim surplus criteria, however, will have no effect on the short-term operations of Hoover, Davis and Parker Dam, and therefore, short-term fluctuations in river reaches downstream of Hoover Dam were not evaluated. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-43 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 213 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Map 3.3-1 Colorado River Locations Selected for Modeling ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-44 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 214 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.3.4.5.1 River Flows Between Hoover Dam and Parker Dam The river flows between Hoover Dam and Parker Dam are comprised mainly of flow releases from Hoover Dam and Davis Dam. Inflows from the Bill Williams River and other intermittent tributaries are infrequent and are usually concentrated into short time periods due to their dependence on localized precipitation. Tributary inflows comprise less than one percent of the total annual flow in this reach of the river. Due to the backwater effect of Lake Mohave, a point on the Colorado River downstream of Davis Dam was used to evaluate the river flows for this reach, located immediately downstream of the Havasu National Wildlife Refuge (NWR). The 90th, 50th, and 10th percentile annual flow volumes for this reach are shown in Figure 3.3-18. As shown by the 50th percentile values, annual flow volumes in this reach can be expected to be greater for the surplus alternatives (except for the Flood Control Alternative) than for the baseline conditions during the 15-year interim surplus criteria period. This is a direct result of more frequent surplus deliveries. The largest increases from baseline conditions occur under the California Alternative and range from approximately 13 percent in the first two years down to three percent by 2016. Results for the Six States and Basin States alternatives are similar to rior other, ranging each Inte from approximately a six percent increase over baseline conditions down17 three to he . of t r 29, 20 percent by 2016. Beyond the 15-year interim period,tthe annual flow volumes under the Dep mbe surplus alternatives are essentially the same (within ovepercent) as those under the one n v. Natio d on N baseline conditions. vajo e in Na rchiv ited level,864, a the magnitudes of the annual flow volumes are c At the 10 percentile -16 although 1 different, the relative 4 No. changes in surplus conditions compared to the baseline conditions th are similar to those at the 50th percentile. At the 90th percentile level, all surplus alternatives (except for the Flood Control Alternative) show annual flow volumes less than or equal to the flows under the baseline conditions. This is the result of more frequent surplus deliveries, which tend to lower Lake Mead reservoir levels. With lower reservoir levels, the frequency of flood control events (which contribute most of the flows at the 90th percentile level) is decreased, which in turn decreases the annual flow volume for a given percentile. The California and Shortage Protection alternatives exhibit the largest decreases, ranging from approximately 13 percent less than baseline conditions in 2006 to one percent less by 2023. Results for the Six States and Basin States alternatives are similar to each other, ranging from approximately six percent less than baseline conditions in 2013 to one percent less by 2023. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-45 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 215 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-18 Colorado River Downstream of Havasu NWR Annual Flow Volume (af) Comparison of Surplus Alternatives to Baseline Conditions th th th 90 , 50 and 10 Percentile Values 90th Percentile 15,000,000 14,000,000 An nu al 13,000,000 Flo w Vol 12,000,000 um e (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 10,000,000 9,000,000 8,000,000 50th Percentile 15,000,000 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in 10,000,000 cited 16864, 149,000,000 No. 14,000,000 An nu al 13,000,000 Flo w Vol 12,000,000 um e (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 8,000,000 10th Percentile 15,000,000 14,000,000 An nu al 13,000,000 Flo w Vol 12,000,000 um e (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 10,000,000 9,000,000 8,000,000 2000 2005 2010 2015 2020 2025 Year COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-46 2030 2035 2040 2045 2050 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 216 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 In Figure 3.3-19, the cumulative distribution of annual flow volumes is shown for year 2006. This is the year of the largest differences at the 90th percentile level as shown in Figure 3.3-18. Although the annual flow volumes decrease for all surplus alternatives (except Flood Control Alternative) at a fixed percentile (i.e. at the 90th percentile) as compared to baseline, the range of annual flow volumes are the same for baseline conditions and the surplus alternatives. The frequency that a flow of a specific magnitude will occur, however, is lower under the surplus alternatives (except for the Flood Control Alternative) as shown in Figure 3.3-19. Figures 3.3-20(a-d) present comparisons of the representative seasonal flows under baseline conditions and the surplus alternatives for 2016. For all seasons, the Flood Control Alternative is very similar to the baseline conditions. The Six States and Basin States alternatives tend to fall between the baseline conditions (and Flood Control Alternative) and the California (and Shortage Protection) alternatives. As expected, the largest flows occur in the spring and summer seasons for baseline conditions and all alternatives due to downstream irrigation demands. For flows that are due primarily to flood control releases from Lake Mead (flows in the 90th – 100th percentile range), the range of mean monthly flows is not changed by the different surplus alternatives, since these magnitudes are dictated by the flood rior control Inte 17 (except regulations. These flows occur, however, less often for thethe surplus alternatives 20 of the Flood Control Alternative). This effect is less ept. pronounced r 29, when most flood in July, v. D vembe control releases have ceased. o ation N N vajo hived on The differences in flows that are,not c to flood control releases are greatest near the in Na 4 r due ited A numericala th c 70 percentile level. -1686 comparison of the 70th percentile values is shown in 4 Table 3.3-13. No. differences in mean monthly flows for the California Alternative The 1 compared to baseline conditions are approximately 16 percent in the winter, nine percent in the spring, six percent in the summer, and eight percent in the fall. For the Basin States alternative, the differences (compared to baseline conditions) in mean monthly flows are approximately three percent in the winter, one percent in the spring, and less than one percent in the summer and fall seasons. Despite these differences, the flows for all alternatives fall well within the minimum and maximum flows for the baseline conditions, as well as within the current operational range for this reach. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-47 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 217 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.3-13 Comparison of Mean Monthly Flow (cfs) – Baseline Conditions and Surplus Alternatives Colorado River Downstream of Havasu NWR (River Mile = 242.3) th 70 Percentile Values for Year 2016 Mean Monthly Flows (cfs) for Year 2016 at the 70th Percentile Season Baseline Basin States Flood Control Six States California Shortage Protection Winter 8069 8347 7965 8317 9327 9223 Spring 15939 16166 15899 16072 17294 17144 Summer 15880 15957 15862 15953 16853 16644 Fall 11776 11805 11776 11686 12688 12531 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-48 8,000,000 9,000,000 10,000,000 11,000,000 12,000,000 13,000,000 14,000,000 15,000,000 16,000,000 17,000,000 18,000,000 19,000,000 0% 25% 3.3-49 Percent of Values Less than or Equal to 50% Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions 90th Percentile Figure 3.3-19 Colorado River Annual Flow Volume Downstream of Havasu NWR Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Annual Flow Volume (af) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 218 of 1200 0% 25% 3.3-50 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Winter Season Flows as Represented by January Flows Figure 3.3-20a Colorado River Seasonal Flows Downstream of Havasu NWR Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 219 of 1200 0% 25% 3.3-51 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Spring Season Flows as Represented by April Flows Figure 3.3-20b Colorado River Seasonal Flows Downstream of Havasu NWR Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 220 of 1200 0% 25% 3.3-52 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Summer Season Flows as Represented by July Flows Figure 3.3-20c Colorado River Seasonal Flows Downstream of Havasu NWR Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 221 of 1200 0% 25% 3.3-53 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Fall Season Flows as Represented by October Flows Figure 3.3-20d Colorado River Seasonal Flows Downstream of Havasu NWR Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 222 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 223 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.3.4.5.2 River Flows Between Parker Dam and Palo Verde Diversion The point on the Colorado used to evaluate the river flows in the reach of the river located between Parker Dam and the Palo Verde Diversion Dam is located immediately upstream of the Colorado River Indian Reservation (CRIR) diversion. The CRIR diversion is located at Headgate Rock Dam, approximately 14 miles below Parker Dam. Flows in this reach of the river result from primarily from releases from Parker Dam (Lake Havasu). Future flows in this reach would be affected by the proposed water transfers and exchanges between the California agricultural water agencies and MWD, which change the point of diversion. For example, under a potential transfer between IID and MWD (or SDCWA), the water that would normally be diverted at Imperial Dam would now be diverted above Parker Dam. As discussed in Section 3.3.3.2, the proposed California intrastate transfers are included in the simulation of the baseline conditions and surplus alternatives. Although the transfers themselves are not a direct result of the proposed interim surplus criteria, the transfers were modeled because they are expected to be a component of the future Lower Basin water supply management programs and to maintain consistency for comparison of the alternatives to baseline conditions. The r intrastate transfers proposed by California and any potential environmental effects that terio and InNEPA17 other would occur as a result of those actions are addressed by separate 0 f the pt. o er 29, 2 environmental compliance. e D v. mb ation on Nove this reach are shown in The 90 , 50 , and 10 percentileo N flow volumes for vaj annualved Figure 3.3-21. As shown N the , archi in bya 450th percentile values, annual flow volumes in this cited 16 greater for the California and Shortage Protection reach can be expected to be86 4alternatives thano. 1 baseline conditions and other alternatives during the 15-year N for the th th th interim surplus criteria period. This is the result of more frequent surplus deliveries under those two alternatives. Increases from baseline conditions under the California Alternative range from approximately seven percent in the first year down to one percent by 2013. A 1.5 percent decrease from baseline conditions is seen for the period 2017 through 2050 as a result of the modeled transfer of 100 kaf from PVID to MWD as part of the California Alternative. Increases from baseline conditions under the Shortage Protection Alternative range from approximately four percent in the first year down to two percent by 2016. The annual flow volumes for the Flood Control, Six States, and Basin States alternatives are essentially the same (less than one percent) as those under the baseline conditions for the entire period of analysis (2002 through 2050). Similar results are seen at the 10th percentile level. Increases from baseline conditions under the California Alternative range from approximately six percent in the first year down to two percent by 2006. A 1.6 percent decrease from baseline conditions is seen for the period 2017 through 2050 as a result of the modeled transfer of 100 kaf from PVID to MWD as part of the California Alternative. Increases from baseline conditions under the Shortage Protection Alternative range from approximately three percent in the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-54 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 224 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Figure 3.3-21 Colorado River Upstream of CRIR Diversion Annual Flow Volume (af) Comparison of Surplus Alternatives to Baseline Conditions th th th 90 , 50 and 10 Percentile Values 90th Percentile 12,000,000 Annual Flow Volume (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 10,000,000 9,000,000 8,000,000 7,000,000 6,000,000 5,000,000 50th Percentile 12,000,000 ior Inter 17 10,000,000 0 f the pt. o er 29, 2 e v. D 9,000,000 mb ation on Nove jo N 8,000,000 Nava archived in cited 16864, 7,000,000 14No. 6,000,000 Annual Flow Volume (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 5,000,000 10th Percentile 12,000,000 Annual Flow Volume (af) 11,000,000 10,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 9,000,000 8,000,000 7,000,000 6,000,000 5,000,000 2000 2005 2010 2015 2020 2025 Year COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-55 2030 2035 2040 2045 2050 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 225 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES first year down to one percent by 2016. The annual flow volumes for the Flood Control, Six States, and Basin States alternatives are essentially the same (less than one percent) as those under the baseline conditions for the entire period of analysis (2002 through 2050). At the 90th percentile level, all surplus alternatives (except for the Flood Control Alternative) show annual flow volumes less than or equal to the flows under the baseline conditions. This is the result of more frequent surplus deliveries, which tend to lower Lake Mead reservoir levels. With lower reservoir levels, the frequency of flood control events (which contribute most of the flows at the 90th percentile level) is decreased, which in turn decreases the annual flow volume for a given percentile. The California and Shortage Protection alternatives exhibit the largest decreases, ranging from two to 20 percent less than baseline conditions from 2002 through 2023, with the largest differences in 2006 and 2016. The Six States and Basin States alternatives exhibit similar behavior, ranging from two to 16 percent less than baseline conditions from 2002 through 2023, with the largest differences in 2016. In Figure 3.3-22, the cumulative distribution of annual flow volumes is shown for year 2006. This is the year of the largest differences at the 90th percentile level as shown in Figure 3.3-21. Although the annual flow volumes decrease for all surplus alternatives ior th Inter percentile) as (except Flood Control Alternative) at a fixed percentile (i.e.hethe 90 017 f t at pt. o er 29, 2 compared to baseline, the range of annual flow volumes are the same for baseline . De that b conditions and the surplus alternatives. tiThe v on frequency em a flow of a specific a Nov magnitude will occur, however, jis lowerved othe surplus alternatives (except for the a o N i under n Nav ar in Flood Control Alternative) as shownch Figure 3.3-22. d in te 4, ci 1686 . 14No COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-56 6,000,000 7,000,000 8,000,000 9,000,000 10,000,000 11,000,000 12,000,000 13,000,000 14,000,000 15,000,000 16,000,000 0% 25% 3.3-57 Percent of Values Less than or Equal to 50% Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions 90th Percentile Figure 3.3-22 Colorado River Annual Flow Volumes Upstream of Colorado River Indian Reservation Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2006 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Annual Flow Volume (af) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 226 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 227 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figures 3.3-23 (a-d) present comparisons of the representative seasonal flows under baseline conditions and the surplus alternatives for 2016. As expected, the largest flows occur in the spring and summer seasons for baseline conditions and all alternatives due to downstream irrigation demands. For flows that are due primarily to flood control releases from Lake Mead (flows in the 90th – 100th percentile range), the range of mean monthly flows is not changed by the different surplus alternatives, since these magnitudes are dictated by the flood control regulations. These flows occur, however, less often for the surplus alternatives (except the Flood Control Alternative). This effect is less pronounced in July, when most flood control releases have ceased. The differences in flows that are not due to flood control releases are similar for all alternatives and baseline conditions. A numerical comparison of the 70th percentile values is shown in Table 3.3-14. The differences in mean monthly flows for the California Alternative compared to baseline conditions are approximately six percent in the winter, three percent in the spring, one percent in the summer, and less than one percent in the fall. For the Basin States alternative, the differences (compared to baseline conditions) in mean monthly flows are less than one percent for all seasons. Table 3.3-14 Comparison of Mean Monthly Flow (cfs) – Baseline Conditions and Surplus Alternatives Colorado River Upstream of CRIR Diversion (River Mile = 180.8) th 70 Percentile Values for Year 2016 ior Inter 17 0 f the pt. o er 29, 2 e v. D Mean Monthly Flows (cfs) for Year 2016 at the 70 Percentile mb ation on Nove Shortage jo N Protection Baseline Six States California av States Flood Control NBasina archived in 3880 3897 4117 4012 cited3897 6864,3895 11690 11690 11690 11690 12009 11793 4-1 1 No. 13025 12990 12989 13025 13194 12984 th Season Winter Spring Summer Fall 8005 7934 8064 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-58 8005 7987 7895 0% 25% 3.3-59 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Winter Season Flows as Represented by January Flows Figure 3.3-23a Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 228 of 1200 0% 25% 3.3-60 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Spring Season Flows as Represented by April Flows Figure 3.3-23b Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 229 of 1200 0% 25% 3.3-61 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Summer Season Flows as Represented by July Flows Figure 3.3-23c Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 230 of 1200 0% 25% 3.3-62 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Fall Season Flows as Represented by October Flows Figure 3.3-23d Colorado River Seasonal Flows Upstream of Colorado River Indian Reservation Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 231 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 232 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.3.4.5.3 River Flows Between Palo Verde Diversion Dam and Imperial Dam The flow of the Colorado River between Palo Verde Diversion Dam and Imperial Dam is normally set at the amount needed to meet the United States diversion requirements downstream of the Palo Verde Diversion plus deliveries to Mexico. The river location that was modeled for this reach of the river is located immediately downstream of the Palo Verde Diversion Dam. As discussed in Section 3.3.4.5.2, the proposed California water interstate transfers are included in the simulation of the baseline conditions and surplus alternatives. The 90th, 50th, and 10th percentile annual flow volumes for this reach are shown in Figure 3.3-24. As shown by the 50th percentile values, annual flow volumes in this reach can be expected to be greater for the California and Shortage Protection alternatives than for the baseline conditions for the first few years of the 15-year interim surplus criteria period. This is a result of more frequent surplus deliveries. The largest increases from baseline conditions occur under the California Alternative and are approximately eight percent during the years 2002 through 2007. After 2007, the annual flow volumes are identical to the baseline conditions. Annual flow volumes under the Shortage Protection Alternative are approximately five percent during the ior In er 17 years 2002 through 2011. After 2011, the annual flow volumes aret identical to the 0 f theand Basin baseline conditions. Results for the Flood Control, pt. States, r 29, 2 States Six o e e v. D alternatives are identical to those undertthe baseline ovemb for the entire period a ion on N conditions N (2002 through 2050). vajo ed in Na rchiv ited level,864, a c At the 10 percentile -16 the California Alternative has the same relative difference (eight percent)No.the years 2002 and 2003, while the Shortage Protection Alternative for 14 th exhibits the same relative difference (five percent) for the years 2002 through 2005. All other results are identical to those observed for the 50th percentile values. At the 90th percentile level, all surplus alternatives (except for the Flood Control Alternative) show annual flow volumes less than or equal to the flows under the baseline conditions. This is the result of more frequent surplus deliveries, which tend to lower Lake Mead reservoir levels. With lower reservoir levels, the frequency of flood control events (which contribute most of the flows at the 90th percentile level) is decreased, which in turn decreases the annual flow volume for a given percentile. The California and Shortage Protection alternatives exhibit the largest decreases, ranging from approximately 17 percent less than baseline conditions in 2006 to four percent less by 2023. Results for the Six States and Basin States alternatives are similar to each other, ranging from approximately 11 percent less than baseline conditions in 2016 to four percent less by 2023. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-63 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 233 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES In Figure 3.3-25, the cumulative distribution of annual flow volumes is shown for year 2006. This is the year of the largest differences at the 90th percentile level as shown in Figure 3.3-24. Although the annual flow volumes decrease for all surplus alternatives (except Flood Control Alternative) at a fixed percentile (i.e. at the 90th percentile) as compared to baseline, the range of annual flow volumes are the same for baseline conditions and the surplus alternatives. The frequency that a flow of a specific magnitude will occur, however, is lower under the surplus alternatives (except for the Flood Control Alternative) as shown in Figure 3.3-25. Figures 3.3-26 (a-d) present comparisons of the representative seasonal flows under baseline conditions and the surplus alternatives for 2016. As expected, the largest flows occur in the spring and summer seasons for baseline conditions and all alternatives due to downstream irrigation demands. For flows that are due primarily to flood control releases from Lake Mead (flows in the 90th – 100th percentile range), the range of mean monthly flows is not changed by the different surplus alternatives, since these magnitudes are dictated by the flood control regulations. These flows occur, however, less often for the surplus alternatives (except the Flood Control Alternative). This effect is less pronounced in July, when most flood control releases have ceased. The differences in flows not due to flood control releases are similar rior alternatives for all th Inte and baseline conditions. A numerical comparison are thef70 e th percentile 17 is 20 values pt. o er 29 the shown in Table 3.3-15. The differences in mean monthly flows for , California . De b Alternative compared to baseline conditions v approximately 10 percent in the winter, ion are Novem at seven percent in the spring,avajo N in ed summer, and eight percent in the fall. For six percent the on N the meanhiv in the Basin States Alternative, 4, arc monthly flows are identical to those under cited all686 baseline conditions for -1 seasons. 4 No. 1 Table 3.3-15 Comparison of Mean Monthly Flow (cfs) – Baseline Conditions and Surplus Alternatives Colorado River Downstream of Palo Verde Diversion Dam (River Mile = 133.8) th 70 Percentile Values for Year 2016 Mean Monthly Flows (cfs) for Year 2016 at the 70th Percentile Season Baseline Basin States Flood Control Six States California Shortage Protection Winter 3516 3516 3516 3516 3865 3760 Spring 9888 9888 9888 9888 10608 10392 Summer 10729 10729 10729 10729 11426 11217 Fall 7191 7191 7191 7191 7749 7582 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-64 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 234 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Figure 3.3-24 Colorado River Downstream Palo Verde Diversion Dam Annual Flow Volume (af) Comparison of Surplus Alternatives to Baseline Conditions th th th 90 , 50 and 10 Percentile Values 90th Percentile 12,000,000 Annual Flow Volume (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 10,000,000 9,000,000 8,000,000 7,000,000 6,000,000 5,000,000 50th Percentile 12,000,000 ior Inter 17 10,000,000 0 f the pt. o er 29, 2 e 9,000,000 v. D mb ation on Nove jo N 8,000,000 Nava archived in 7,000,000 cited 16864, 146,000,000 No. Annual Flow Volume (af) 11,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 5,000,000 10th Percentile 12,000,000 Annual Flow Volume (af) 11,000,000 10,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 9,000,000 8,000,000 7,000,000 6,000,000 5,000,000 2000 2005 2010 2015 2020 2025 Year COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-65 2030 2035 2040 2045 2050 5,000,000 6,000,000 7,000,000 8,000,000 9,000,000 10,000,000 11,000,000 12,000,000 13,000,000 14,000,000 15,000,000 0% 25% 3.3-66 Percent of Values Less than or Equal to 50% Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions 90th Percentile Figure 3.3-25 Colorado River Annual Flow Volumes Downstream of Palo Verde Irrigation Diversion Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2006 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Annual Flow Volume (af) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 235 of 1200 0% 25% 3.3-67 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Winter Season Flows as Represented by January Flows Figure 3.3-26a Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 236 of 1200 0% 25% 3.3-68 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Spring Season Flows as Represented by April Flows Figure 3.3-26b Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 237 of 1200 0% 25% 3.3-69 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Summer Season Flows as Represented by July Flows Figure 3.3-26c Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 238 of 1200 0% 25% 3.3-70 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Fall Season Flows as Represented by October Flows Figure 3.3-26d Colorado River Seasonal Flows Downstream of Palo Verde Diversion Division Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 239 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 240 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.3.4.5.4 River Flows Between Imperial Dam and Morelos Dam The flows in the Colorado River below Imperial Dam are primarily comprised of the water delivered to Mexico in accordance with the Treaty. Mexico's principal diversion is at Morelos Dam, which is located, approximately nine miles southwest of Yuma, Arizona. Mexico owns, operates, and maintains Morelos Dam. The reach of river between Morelos Dam and the SIB is commonly referred to by Reclamation as the Limitrophe Division. Reclamation's authority in this division is limited to maintaining the bankline road, the levee, various drains to the river, and the U.S. Bypass drain that carries agricultural drainage water to the Cienega de Santa Clara in Mexico. Under International Treaty the United States Section of the IBWC is obligated to maintain the river channel within this division. Reclamation provides assistance to the IBWC, when requested, for maintenance needs in this reach of the river. Minute 242 (Minutes are defined as decisions of IBWC and signed by the Mexican and United States commissioners) of IBWC and the Mexican Water Treaty of 1944 provide requirements for deliveries at the NIB and SIB near Yuma and San Luis, Arizona, respectively. Up to 140,000 af annually of agricultural drainage wateror be delivered eri can to Mexico at the SIB. The remaining 1,360,000 af of waterthe Int delivered to Mexico is to be 017 f at the NIB annually and diverted at Morelos Dam eptheo to t. Mexicali Valley. For several 29, 2 D ber years after the United States Bypass Drainn v. completed in 1978, the Colorado River io was Novem at Channel downstream of Moreloso N was d on vaj Damhive normally dry. Flows below Morelos Dam a now occur only when in N in excess of Mexico's requirement arrive at the NIB. d water , arc cite 16864 14Much of the NIB water is diverted at Imperial Dam into the All-American Canal (AAC) No. where it is returned to the bed of the Colorado River through Siphon Drop and Pilot Knob Powerplants. A portion of the NIB deliveries remains in the river, passing through Imperial and Laguna Dams to Morelos Dam. Water in excess of Mexico's water order at the NIB is normally passed through Morelos Dam, through the Limitrophe Division, and into the original Colorado River channel downstream. Water in excess of Mexico's water order occurs primarily when flood releases are made from Lake Mead. Excess water arriving at the NIB may also result from flooding on the Gila River, and from operational activities upstream (i.e., cancelled water orders in the United States, maintenance activities, etc.). In December of each year, Mexico provides to the United States an advance monthly water order for the following calendar year. Normally, this water order can only be changed by providing the United States with written notice, 30 days in advance and each monthly water order can be increased or decreased by no more than 20 percent of the original monthly water order. The Treaty further stipulates that Mexico's total water order must be no less than 900 cfs and no more than 5500 cfs during the months of January, February, October, November and December. During the remainder of the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-71 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 241 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 year, Mexico's water order must be no less than 1500 cfs and no more than 5500 cfs. Daily water orders are usually not allowed to increase or decrease by more than 500 cfs. As discussed in Section 3.3.3.3, the model accounts for the all deliveries to Mexico diversions at the NIB (Morelos Dam). Flows that are modeled downstream of Morelos Dam represent mean monthly flows that are excess flows in the Colorado River due to Lake Mead flood control releases. These excess flows may reach the Colorado River Delta, although Mexico has the authority to divert them for other uses. Such decisions by Mexico are not modeled. The excess flows are over and above Mexico’s normal 1.5 mafy water entitlement, plus the 200,000 afy for surplus deliveries. The 90th, 50th, and 10th percentile annual flow volumes for this reach are shown in Figure 3.3-27. Since these flows are dependent solely upon infrequent flood control releases, no flows are observed at either the 10th or 50th percentiles. At the 90th percentile level, all surplus alternatives (except for the Flood Control Alternative) show annual flow volumes less than or equal to the flows under the baseline conditions. This is the result of more frequent surplus deliveries, which tend to lower Lake Mead reservoir levels. With lower reservoir levels, the frequency of flood control events is decreased, which in turn decreases the annual flow volume for a given percentile. The California and Shortage Protection alternatives exhibit the largest decreases, ranging ior Inter 12 7 from approximately 70 percent less than baseline conditionshe 2016 to01 percent less in of t 9 2 by 2023. Results for the Six States and Basin Statespt. alternatives are ,similar to each D .lesse ember 2 other, ranging from approximately 47ation v percent than Nov baseline conditions in 2013 to 12 percent less by 2023. avajo N ved on N hi ed in 864 arc itthe cumulative,distribution of annual flow volumes is shown for year c In Figure 3.3-28, -16 o. 14 2006. This is the year of the largest differences at the 90th percentile level as shown in N Figure 3.3-27. Although the annual flow volumes decrease for all surplus alternatives (except Flood Control Alternative) at a fixed percentile (i.e. at the 90th percentile) as compared to baseline, the range of annual flow volumes are the same for baseline conditions and the surplus alternatives. The frequency that a flow of a specific magnitude will occur, however, is lower under the surplus alternatives (except for the Flood Control Alternative) as shown in Figure 3.3-28. Additional analysis of annual flow volumes in this reach is presented in Section 3-16. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-72 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 242 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.3-27 Colorado River Below Mexico Diversion at Morelos Dam Annual Flow Volume (af) Comparison of Surplus Alternatives to Baseline Conditions th th th 90 , 50 and 10 Percentile Values 90th Percentile 5,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative Annual Flow Volume (af) 4,000,000 3,000,000 2,000,000 1,000,000 0 50th Percentile 5,000,000 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Annual Flow Volume (af) 4,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 3,000,000 2,000,000 1,000,000 0 10th Percentile 5,000,000 Annual Flow Volume (af) 4,000,000 Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 3,000,000 2,000,000 1,000,000 0 2000 2005 2010 2015 2020 2025 Year COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-73 2030 2035 2040 2045 2050 0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 7,000,000 8,000,000 0% 10% 20% 30% 50% 60% 3.3-74 Percent of Values Less than or Equal to 40% Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative 70% 80% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions 90th Percentile Figure 3.3-28 Colorado River Annual Flow Volumes Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2006 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Annual Flow Volume (af) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 90% 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 243 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 244 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figures 3.3-29 (a-d) present comparisons of the representative seasonal flows under baseline conditions and the surplus alternatives for 2016. As expected, the only differences are seen for flows that are due to flood control releases from Lake Mead (flows in the 90th – 100th percentile range). As seen in the figures, the range of mean monthly flows is not changed by the different surplus alternatives, since these magnitudes are dictated by the flood control regulations. These flows occur, however, less often for the surplus alternatives (except the Flood Control Alternative). This effect is less pronounced in July, when most flood control releases have ceased. A numerical comparison of the 90th percentile values is shown in Table 3.3-16. The differences in mean monthly flows for the California Alternative compared to baseline conditions are approximately 51 percent in the winter, zero percent in the spring, zero percent in the summer, and 100 percent in the fall. For the Basin States alternative, the differences (compared to baseline conditions) in mean monthly flows are approximately one percent in the winter, zero percent in the spring, and zero percent in the summer and 100 percent in the fall seasons. The large fluctuating differences are due to the infrequent nature of these flows and are indicative of the decreased frequency of occurrence due to the interim surplus criteria. ior Inter 17 0 f the pt. o er 29, 2 e .D b ion v N 2016 atm atFlows (cfs) for Yearove the 70 Percentile Mean Monthly on jo N Shortage Nava archived in Protection States Baseline Flood Control Six States California ited 6Basin4, c 86 8052 8125 8052 3983 2706 4-1 . 18125 No 0 0 0 0 0 0 Table 3.3-16 Comparison of Mean Monthly Flow Data – Baseline Conditions and Surplus Alternatives Colorado River Downstream of Morelos Dam (River Mile = 23.1) th 90 Percentile Values (cfs) for Year 2016 th Season Winter Spring Summer Fall 0 0 0 0 0 0 3007 0 3007 0 0 0 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.3-75 0% 25% 3.3-76 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Winter Season Flows as Represented by January Flows Figure 3.3-29a Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 245 of 1200 0% 25% 3.3-77 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Spring Season Flows as Represented by April Flows Figure 3.3-29b Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 246 of 1200 0% 25% 3.3-78 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Summer Season Flows as Represented by July Flows Figure 3.3-29c Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 247 of 1200 0% 25% 3.3-79 Percent of Values Less than or Equal to 50% 75% ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Baseline Conditions Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 0 5,000 10,000 Flo w (cf 15,000 s) 20,000 25,000 30,000 Fall Season Flows as Represented by October Flows Figure 3.3-29d Colorado River Seasonal Flows Below Mexico Diversion at Morelos Dam Comparison of Surplus Alternatives to Baseline Conditions for Modeled Year 2016 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 100% CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 248 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 249 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.5 3.5.1 CHAPTER 3 WATER QUALITY INTRODUCTION This section addresses the salinity of the Colorado River and mainstream reservoirs, and the quality of Lake Mead water available for municipal and industrial purposes. The potential changes in the operation of the Colorado River system downstream from Lake Powell under interim surplus criteria alternatives could temporarily affect the salinity of Colorado River water, which affects municipal and industrial uses in the Lower Basin. In addition, changes in Lake Mead water levels could affect the quality of water arriving at the SNWS pump intakes in the Boulder Basin of Lake Mead, and thereby affect the quality of the water supply for the Las Vegas Valley. 3.5.2 COLORADO RIVER SALINITY This section discusses potential effects that could result from the implementation of the interim surplus criteria alternatives under consideration. Salinity has long been recognized as one of the major problems of the Colorado River. “Salinity” or “total dissolved solids” (TDS) include all of the soluble constituents dissolved in a river and the two terms are used interchangeably in this document. This sectionior er considers e Int 017 hto Imperial Dam. The potential changes in salinity concentrations from Lake.Mead 2 of t ept effectsr of 9, section also presents a general discussion of the D . adverse mbe 2 increased salinity nv e concentrations on municipal and o Natio systems. ov industrial nN vaj ed o in Na 4, archiv 3.5.2.1 METHODOLOGY 6 cited 168 . 14Reclamation’sNo model for salinity is used to create salinity reduction targets for the Colorado River Basin Salinity Control Program (SCP). To do this, the model simulates the effects of scheduled water development projects to predict future salinity levels. This data is then used to compute the amount of new salinity control projects required to reduce the river’s salinity to meet the standards at some point in the future (2015). The model itself does not include future salinity controls because implementation schedules for future salinity control projects are not fixed and vary considerably. The salinity control standards are purposefully designed to be long-term (nondegradation) goals, rather than exceedence standards used for industry or drinking water. By definition, the SCP is designed to be flexible enough to adjust for any changes caused by the various alternatives being considered. Therefore, it could be concluded that there would be no change in compliance with the standards caused by selecting any one of the alternatives. However, for the purposes of this analysis, each alternative has been evaluated using fixed (existing) levels of salinity controls to identify the differences between alternatives and the baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 250 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 General effects of salinity were determined from review of records of historic river flow and salinity data available and economic impacts presented in Quality of Water Colorado River Basin – Progress Report No. 19, 1999, U.S. Department of the Interior; Water Quality Standards for Salinity Colorado River System, 1999 Review, June 1999, Colorado River Basin Salinity Control Forum and Salinity Management Study, Technical Appendices, June 1999, Bookman-Edmonston Engineering, Inc. The salinity program as set forth in the Forum's 1999 Annual Review enables the numeric criteria to be met through the year 2015. Therefore, it was presumed that the criteria would be maintained through 2015. Although the 1999 Review considers only the period to 2015, it was presumed that future additions to the salinity control program will be sufficient to maintain the criteria through 2050. 3.5.2.2 3.5.2.2.1 AFFECTED ENVIRONMENT Historical Data The Colorado River increases in salinity from its headwaters to its mouth, carrying an average salt load of nine million tons annually past Hoover Dam. Approximately half (47 percent) of the salinity concentration is naturally caused and 53erior of the t percent he Inrunoff,17 concentration results from human activities including agricultural 20 evaporation of t ep . ber 29, and municipal and industrial sources (Forum, 1999). t v. D n em Natio d on Nov period of record 1941 through Salinity of the river has fluctuated significantly over the vajo e in Na 4, archiv concentrations have ranged from 833 1997. Below Hoover Dam, annual salinity d cite 86 milligrams per liter 14-16in 1956 to 517 mg/l in 1986. However, the maximum . (mg/l) No monthly fluctuation in any year is approximately 50 mg/l. Salinity of the river is influenced by numerous factors including reservoir storage, water resource development (and associated return flows), salinity control, climatic conditions and natural runoff. The impact of reservoir storage has all but eliminated seasonal fluctuations in salinity. Annual variations in salinity are primarily driven by natural, climatic variations in precipitation and snowmelt runoff. These hydrologic variations cause differences in both flow and salinity. As shown in Figure 3.5-1, the salinity of the river varied by as much as 1000 mg/l prior to the construction of Glen Canyon Dam in 1961. By the 1980s, that variation was reduced to about 200 mg/l due to the mixing and dampening effect of the large volume of storage in Lake Powell. Figures 3.5-2 and 3.5-3 show the comparison between mainstream flows and salinity. Figure 3.5-2 shows the outflow from Glen Canyon and Imperial Dams. Figure 3.5-3 shows the salinity at Imperial, Hoover and Glen Canyon dams. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 251 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.5-1 Historical Monthly Salinity Concentrations Below Glen Canyon Dam (1940-1995) 1600 1400 Dam closure and reservoir storage in mid1960's reduced variation in salinity Monthly Salinity (mg/L) 1200 1000 800 600 400 200 0 1940 ior Inter 17 0 f the pt. o er 29, 2 e .D b 1945 1950 1955 1960 on v 1970 1975 m ati1965 on Nove 1980 1985 1990 jo N Nava archived in cited 16864, 14No. Regulatory Requirements and Salinity Control Programs 1995 2000 Year 3.5.2.2.2 In 1972, the EPA promulgated regulations requiring water quality standards for salinity, numeric criteria and a plan of implementation for salinity control. The Seven Colorado River Basin States, acting through the Forum, adopted numeric criteria for flowweighted average annual salinity, at three points on the river as shown below: Below Hoover Dam 723 mg/l Below Parker Dam 747 mg/l At Imperial Dam 879 mg/l COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-3 1970 0 5 10 15 20 25 1975 Imperial Dam 1980 3.5-4 Year 1985 1990 1995 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N Glen Canyon Dam vajo hived Na d in 64, arc cite 168 o. 14 N Lake Powell fills in 1980 and the entire reservoir system spills in 1983 - 1986. Figure 3.5-2 Historical Glen Canyon Dam and Imperial Dam Releases COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Annual Discharge (mafy) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2000 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 252 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 253 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Figure 3.5-3 Historical Salinity Concentrations of Releases from Glen Canyon, Hoover, and Imperial Dams 1000 900 Imperial Dam 800 Hoover Dam Salinity (mg/L) 700 600 500 Glen Canyon Dam 400 300 ior Inter 17 e 0 200 of th pt.1990 er 29, 2 1970 1975 1980 1985 1995 2000 e D Year mb n v. atio Nove ajo N ived on Nav d in 64, arch cite 16to These criteria applied only 8 the lower portion of the Colorado River from Hoover 4Dam to Imperialo. 1 Below Imperial Dam, salinity control is a federal responsibility N Dam. to meet the terms of Minute 242 to the U.S.-Mexico Water Treaty of 1944. Minute 242 requires that salinity concentrations upstream of Mexico’s diversion be no more than 115 mg/l + 30 mg/l TDS higher than the average salinity of water arriving at Imperial Dam. In 1974, the Colorado River Basin Salinity Control Act (P.L. 93-320) was enacted. The Act contains two Titles: 1) Title I provides the means for the United States to meet its commitment to Mexico; and 2) Title II creates a salinity control program within the Colorado River Basin in order that the numeric criteria will be maintained while the Basin States continue to develop their apportionment of Colorado River water. The federal/state salinity control program is designed to maintain the flow-weighted average annual salinity at or below the numeric criteria. The program is not intended to counteract short-term salinity variations resulting from short-term water supply. Federal regulations provide for temporary increases above the criteria due to natural variations in flows. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 254 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 The seven Basin States acting through the Forum reviews the numeric criteria and plan of implementation every three years and makes changes in the plan of implementation to accommodate changes occurring in the Basin States. The latest review was in 1999. The review is currently undergoing adoption by the Basin States and approval by EPA. At each triennial review, the current and future water uses are analyzed for their impact on the salinity of the Colorado River. If needed, additional salinity control projects are added to the plan to assure compliance with the standards. The need for one or more additional salinity control projects is determined by monitoring the salinity of the river and making near-term projections of changes in diversions from and return flows to the river system. When an additional project is needed, it is selected from a list of potential projects that have undergone feasibility investigation. A proposal to implement the project is made through coordination with the Basin States. In selecting a project, considerable weight is given to the relative costeffectiveness of the project. Cost-effectiveness is a measure of the cost per ton of salt removed from the river system or prevented from entering the river system. Other factors are also considered, including environmental feasibility and institutional acceptability. ior Inter 17 It is estimated that 1,478,000 tons of salt will need to beof the or, prevented from removed 20 ept. ber 29 entering the Colorado River system to maintain D salinity concentration at or below n v. the o have been controlled and an em the criteria through 2015. To date, Nati720,000 tons v over o nN o vajo additional 756,000 tons will need to chived in Na 4, ar be controlled through 2015. cited 1686 3.5.1.1.3 General Municipal, Industrial, and Agricultural Effects of Increased 14No. Salinity Concentrations High salinity concentrations can cause corrosion of plumbing, reduce the life of waterusing appliances, and require greater use of cleaning products. Industrial users incur extra water treatment costs. Increased salinity in drinking water can create unpleasant taste, often resulting in the purchase of bottled water or water treatment devices. Agriculture experiences economic losses from high salinity through reduced crop productivity and the need to change from less salt-tolerant high value crops, to more salt-tolerant low value crops. Increased salinity can also require more extensive agricultural drainage systems. High salinity is a significant constraint to water recycling and groundwater replenishment programs. Compliance with regulatory requirements imposed by local water quality management programs to protect groundwater supplies can add significantly to the economic impacts. Restrictions have been placed on reuse or recharge of waters that exceed specific salinity levels. Such restrictions significantly constrain groundwater replenishment programs and wastewater reuse programs. Should salinity of the Colorado River increase, these regulatory actions could create a need for COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 255 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 more expensive water treatment processes, such as reverse osmosis, prior to disposal or reuse. If disposal is selected, additional water supplies would need to be developed to meet demands that could have been met by water reuse. Reclamation has determined that the economic damages from Colorado River salinity in the three Lower Division states served by Colorado River water amount to $2.5 million per mg/l. Figure 3.5-4 shows the relationship between costs of damages and salinity concentrations. Therefore it is assumed for this analysis that the baseline conditions will reflect the numeric criteria at each station of interest (below Hoover Dam, below Parker Dam, and at Imperial Dam). ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-7 $0.0 400 $0.5 $1.0 $1.5 $2.0 500 600 800 3.5-8 Salinity at Imperial Dam (mg/l) 700 900 1,000 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na At 1997 observed levels d in 64, arc cite 168 o. 14 N At numeric criteria level Figure 3.5-4 Estimated Cost of Damages Associated with Increased Salinity Concentrations COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Salinity Damages (billions) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 1,100 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 256 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 257 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.5.1.3 CHAPTER 3 ENVIRONMENTAL CONSEQUENCES The effects of the alternatives on the salinity of Colorado River water focus on their differences from baseline conditions. Since the current model configuration does not include any salinity control projects beyond those currently in place, modeling of baseline conditions indicates increases in salinity due to projected increased water consumption in the Upper Basin. However, in practice, these increases would be offset by salinity control projects that would continue to be implemented. Tables 3.5-1 and 3.5-2 present these differences for years 2016 and 2050, respectively. The TDS values represent the mean values for the flow-weighted annual averages for the given year. The first column under each monitoring station heading in the tables presents the model projected TDS concentrations under the five alternatives calculated by applying the difference to the baseline TDS level. The second column presents the difference between the values for each alternative compared with baseline conditions. As shown in Table 3.5-1, there is, in general, very little effect on TDS (less than one percent) due to interim surplus criteria in the year 2016. The exception is the decrease at Imperial Dam for the California Alternative of 19 mg/l (about 2.2 percent). This is r due to the assumption in the model of an additional transfer fromnterioto MWD of I PVID 17 100,000 af during normal and Tier 3 surplus conditions,of the reduces 0 salt pickup which 2 the ept. ber 29, in the return flows. v. D m n e Natio d on Nov ajo tend itoe In general, the surplus alternatives h v decrease TDS values slightly. These Nav d in 64, arc decreases are duete increased equalization releases from Lake Powell relative to ci to 168 baseline. 14No. As shown in Table 3.5-2, interim surplus criteria have no effect on TDS values by the year 2050, with the exception of the PVID to MWD transfer assumed in the California Alternative. 3.5.3 LAKE MEAD WATER QUALITY AND LAS VEGAS WATER SUPPLY This analysis addresses potential impacts of interim surplus criteria alternatives on water quality in Lake Mead, and potential changes to water quality and levels of contaminants at the SNWA intakes. This is a qualitative analysis based on system modeling and existing limnological studies. 3.5.3.1 METHODOLOGY Evaluation of the environmental consequences of each operational alternative to Lake Mead water quality and Las Vegas water supply are based on a qualitative assessment of existing limnological and hydrodynamic data, and hydrologic modeling as discussed in Section 3.3. Each interim surplus criteria alternative was modeled for comparison to baseline projections. Modeling focused on the probability of decreased Lake Mead COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 258 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.5-1 Estimated Colorado River Salinity in 2016 Unit: Total Dissolved Solids (mg/l) Below Hoover Dam Alternative Value Below Parker Dam At Imperial Dam Departure from Baseline Value Departure from Baseline Value Departure from Baseline Baseline 1 Conditions 723 NA 747 NA 879 NA Basin States 719 -2 737 -2 879 0 Flood Control 723 0 745 -0 879 0 Six States 719 -2 738 -2 881 0 California 712 -5 734 -5 853 -19 Shortage Protection 715 -4 736 -4 872 -3 1 ior Inter 17 0 f the pt. o er 29, 2 e .D mb ion v atTable 3.5-2 Nove on jo N ve River Estimated i Nava aColoradod Salinity in 2050 in rch 64, cited 168Unit: Total Dissolved Solids (mg/l) 14Below Parker Dam At Imperial Dam No. Below Hoover Dam Baseline conditions assume compliance with the numeric criteria at the locations cited. Value Departure from Baseline Value Departure from Baseline Value Departure from Baseline Baseline 1 Conditions 723 NA 747 NA 879 NA Basin States 723 0 747 0 877 0 Flood Control 723 0 747 0 879 0 Six States 723 0 747 0 878 0 California 722 -1 745 0 857 -24 Shortage Protection 722 -1 747 0 876 0 Alternative 1 Baseline conditions assume compliance with the numeric criteria at the locations cited. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 259 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 surface elevations, which could exacerbate effects of discharge of Las Vegas Wash water into Boulder Basin. Assessment of potential effects on water quality of Lake Mead, including consideration of Las Vegas Wash inflow on the SNWA intake, relied primarily on system modeling information associated with the probability of future Lake Mead surface elevations. Previous studies of Lake Mead were also an important source of information, particularly those focusing on Boulder Basin, Las Vegas Wash, and hydrodynamics potentially affecting intake water quality. As discussed in Section 3.3, modeling identified probabilities associated with surface water elevations under baseline conditions as well as projections associated with implementation of the interim surplus criteria alternatives over a 50-year period. As discussed previously, model output utilized for this water quality analysis assumes shortage determinations would occur, if necessary, to protect a surface elevation of 1083 feet msl, which is the Lake Mead minimum power pool elevation. The primary SNWA intake at Saddle Island is at 1050 feet msl, and the secondary intake is at 1000 feet msl. Thus, assuming a strategy to protect 1083 feet msl also provides a level of protection to SNWA’s intake water quality. ior Inter 17 As discussed below, contaminant dilution and lake water f the are, directly o quality29 20 ept. in berassessment is a proportional to lake volume. As such, a critical D v. element mthis ation on Nthee comparison of projected Lake Mead volumes under ov five action alternatives relative jo N ved to baseline conditions. n Navhydrologic modeling output, median Lake Mead volumes Using a i rchi and surface areastwere identified for each of the alternatives associated with projected i ed 6864, a c reservoir elevations14-1 the median modeled probabilities. Modeling results under No. indicating these parameters were then developed for the years 2016, 2026, 2036, and 2050. Separate comparisons were then made of the volume and surface area for each alternative as compared to baseline conditions. 3.5.3.2 AFFECTED ENVIRONMENT The focus of this section is a description of the affected environment related to Lake Mead water quality and the SNWA intake locations, with specific consideration of hydrodynamics of the Colorado River Basin, limnology and water quality (factors that may be influenced by implementation of interim surplus criteria alternatives). 3.5.3.2.1 General Description Lake Mead is a large mainstream Colorado River reservoir in the Mohave Desert, within the States of Arizona and Nevada as shown on Map 3.2-1. Lake Mead, formed in 1935 following the construction of Hoover Dam, is the largest reservoir in the United States by volume (26 maf active storage). At full pool (reservoir elevation 1221 feet msl), Lake Mead extends 108 miles from Black Canyon (Hoover Dam) to Separation Canyon COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 260 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 at the upstream end. Lake Mead has four large sub-basins including Boulder, Virgin, Temple and Gregg. Between these basins are four narrow canyons: Black, Boulder, Virgin and Iceberg. Over 170,000 square miles of the Colorado River Basin watershed are located above Hoover Dam. Boulder Basin, SNWA intake locations and the Las Vegas Wash are shown on Map 3.5-1. The Muddy and South Virgin mountains border the reservoir on the north, and the Virgin and Black mountains and various desert hills border the reservoir on the south. The shoreline is extremely irregular with a Shoreline Development Value (SLD) of 9.7 (Paulson and Baker, 1981). SLD is the ratio of the length of the shoreline of a lake or reservoir to the length of the circumference of a circle with an area equal to that of the lake (Wetzel, 1975). The shoreline includes several large bays, including Las Vegas and Bonelli, and numerous coves. The principal morphometric characteristics of Lake Mead are summarized below in Table 3.5-3. Table 3.5-3 Morphometric Characteristics of Lake Mead Parameter Units Value ior 1,205 Inter 17 590 0 180 f the pt. o er 29, 2 e v. D 231 mb ation on Nove N 30 jo 108 Nava archived in 17 cited 16864, 9.7 . 14No Normal operating level (spillway crest) Maximum depth Mean depth Surface area Volume (including dead storage) Maximum length Maximum width Shoreline development Discharge depth Annual discharge (approximate) Replacement time at maximum operating level feet feet feet square miles maf miles miles Index Value feet maf years 310 10 3.9 Derived from Interior (1966), Lara and Sanders (1970), Hoffman and Jonez (1973) LaBounty and Horn (1997) conducted a study of the influence of drainage from the Las Vegas Valley on the limnology of Boulder Basin that is highly relevant to the issue addressed in this section. Unless otherwise noted, the descriptions of reservoir characteristics, hydrodynamics, and general limnology of Lake Mead are drawn from this study. The Colorado River contributes about 98 percent of the annual inflow to Lake Mead; the Virgin and Muddy rivers and Las Vegas Wash provide the remainder. Annual flows from Las Vegas Wash are approximately 155,000 af, providing the second highest inflow into Lake Mead. Discharge from Hoover Dam is hypolimnetic and occurs 285 feet below the normal operating shown above (1205 feet msl). Average annual discharge is approximately 10 maf. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 261 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Boulder Basin, the lowermost basin of Lake Mead, receives all nonpoint surface and groundwater discharges and treated effluent from the Las Vegas Valley and municipal wastewater treatment facilities via drainage from Las Vegas Wash into Las Vegas Bay. Boulder Basin is 9.3 miles wide from Boulder Canyon to Hoover Dam (Black Canyon), and the distance from the confluence of Las Vegas Wash to Hoover Dam is approximately 9.9 miles. The historical Colorado River channel lies along the eastern side of Boulder Basin. Due to effects of urban runoff and treatment plant effluents on the discharge through Las Vegas Wash (discussed later in this section), Boulder Basin has the highest nutrient concentrations in the Lake Mead system (Paulson and Baker, 1981; Prentki and Paulson, 1983). This is in contrast to the normal upstream-downstream decrease in the pattern of productivity more typical of reservoirs, and results in several limnological features within Boulder Basin that are normally associated with upstream reaches (Kimmel et al., 1990). Overall, Lake Mead is mildly mesotrophic based on several classification indices (Vollenweider 1970; Carlson 1977), including chlorophyll a concentration and secchi transparency measurements. Chlorophyll concentration is a measure of algal biomass ior and can, therefore, be interpreted as an index of lake productivity. tSecchi disk In er 17 e measurements are used to determine the depth to which of thpenetrates0 pt. light er 29, 2 lake water and help to establish the euphotic zone which marksDe areamb lake where primary v. that ve of a o ation on Noccurs. productivity (energy production jby N o photosynthesis) va ed in Na 4, archiv d input into Las Vegas Bay, chlorophyll concentrations have Due to abundantinutrient 686 c te 1 3 been measured greater o. 14than 100 milligrams per cubic meter (mg/m ). Secchi N transparency readings of less than two feet have been measured in the inner bay (LaBounty and Horn, 1997). However, secchi transparency increases to over 16 feet, and chlorophyll a is reduced by 90 percent within the first 2.6 miles from the Las Vegas Wash inflow. These findings suggest that Boulder Basin is a relatively isolated embayment and that it is much more productive than the lake as a whole. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-13 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-14 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Map 3.5-1 Las Vegas Wash and SNWA Lake Mead Intake Facilities at Saddle Island AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 262 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 263 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 The Federal Water Pollution Control Act (Clean Water Act) Amendments of 1972 and 1977 require the control of all sources of water pollution in meeting the goals of the Act. Section 208 of the Act requires that all activities associated with water pollution problems are planned and managed through an integrated area-wide water quality management program. It also defines the schedule and scope of area-wide wastewater treatment management plans. The 1997 Las Vegas Valley 208 Water Quality Management Plan Amendment certified by the State of Nevada and EPA, is a 20-year plan that comprehensively addresses the quality and quantity of the Valley’s point source (discharges from wastewater treatment facilities) and non-point sources (groundwater, stormwater issues, Las Vegas Wash, agricultural diffuse sources), and revisions of water quality standards. The water quality requirements currently being met by the wastewater discharges of the Las Vegas Valley have a long history. Beginning in the 1950s with requirements for secondary treatment, through the 1970s and the promulgation of the Clean Water Act, and into the 1990s with more advanced nutrient removal requirement, the quality and volume of treated wastewater discharged to Lake Mead has continued to increase and will continue to meet standards into the future through the Section 208 process (Clark County, 1997). r terio he In 2017 The Lake Mead Water Quality Forum, established bytthe f t p . o Nevada Division of 29, Environmental Protection (NDEP), has been v. De ember as an avenue for identified in the Plan n coordinated research opportunities and tsolutions to the water quality issues that face Las Na io d on Nov ajo e Vegas Valley and Laken Navin therfuture. The forum is comprised of federal, state and i Mead 4, a chiv d vested interest in Lake Mead’s water quality. The Lake Mead cite 1686 local agencies with a Water QualityNo. 14 responsible for issue identification, coordination and defining forum is the process approach in identifying issues regarding water quality and potential impacts to the water supply. The Las Vegas Wash Coordination Committee (LVWCC) is comprised of more than two dozen members of local, state, and federal agencies, business owners and members of the public. The LVWCC was tasked with the support, development and implementation of the Las Vegas Wash Comprehensive Adaptive Management Plan (LVWCAMP). The planning phase of the LVCAMP is now complete, and various actions presented in the plan are currently in progress to restore the wash, its wetlands, and its ability to improve the quality of return flows into Lake Mead. Reclamation is an active member of both of these groups and has been independently funding research on Lake Mead water quality prior to their formation and is now a funding partner with other agencies for ongoing studies on the Wash and Lake Mead. Water quality in Lake Mead and Las Vegas Wash are the subject of numerous articles and the chemical and physical analyses of raw and treated Lake Mead source water is published on SNWA’s website (http://www.snwa.com). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-15 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 264 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.5.3.2.2 CHAPTER 3 Lake Mead Water Quality and Limnology Water quality of Lake Mead and the Colorado River is alkaline with a pH of 8.3 and an average concentration of TDS of approximately 700 mg/l. Chemical characteristics of the river at the inflow to Lake Mead, near the outflow at Hoover Dam, and at Lake Mohave are shown below in Table 3.5-4. Table 3.5-4 Chemical Characteristics of Colorado River Parameter pH Conductivity Total Dissolved Solids Calcium Magnesium Potassium Bicarbonate Sulfate Chloride Silica Nitrate Phosphate 1 Gage Station Location1 Units umho/cm mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l Grand Canyon 2 Hoover Dam Davis Dam 8.0 945 617 74 26 4.1 170 228 79 7.0 .50 .010 7.7 1086 705 86 28 4.9 163 283 85 8.3 .41 .013 8.0 1089 714 84 29 5.0 157 293 87 7.8 .28 -- ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N i NavaSeptemberved USGA data, average ford in 1975 – arch 1976 ite October6864, c -1 o. 14 N The principal constituents of TDS are the anions of sulfate, carbonate and chloride and the cations of sodium, calcium, magnesium and potassium. Nitrate concentrations are moderate (0.28 to 0.50 mg/l), but phosphorus is extremely low (0.01 to 0.03 mg/l). Silica is present in very high concentrations (7.0 to 8.3 mg/l). Limnological investigations of Lake Mead have found that 80 percent of the inorganic nitrogen within the lake is provided by the Colorado River, and that Las Vegas Wash contributes 70 percent of the inorganic phosphorus (Paulson, Baker, Deacon, 1980). The Upper Basin of Lake Mead was found to be phosphorus-limited, and the Lower Basin nitrogen-limited during the summer. Equal proportions of nitrogen and phosphorous were retained in the Upper Basin of Lake Mead, but nitrogen retention decreased to seven percent, and phosphorus to 33 percent in the Lower Basin. Additionally, the high nitrate loss from Hoover Dam greatly reduced nitrogen retention in the Lower Basin of Lake Mead. In 1978 the EPA estimated that Lake Mead retained 93 percent of the total phosphorus input versus 52 percent of total nitrogen (EPA, 1978). Phosphorus concentrations are COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-16 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 265 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 low in the Upper Basin of the lake due to the low input from the Colorado River, a result of sediment trapping that occurs upstream within Lake Powell. As recently as 1998, new contaminants to Lake Mead have been discovered as a part of the nonpoint pollutant load of Las Vegas Wash (EPA, 2000). Perchlorate has been detected in the water of the Colorado River and Lake Mead. Ammonium perchlorate is manufactured as an oxygen-adding compound in solid rocket fuel propellant, missiles and fireworks. The EPA identified two facilities that manufactured ammonium perchlorate in Henderson, Nevada, that were found to have released perchlorate to groundwater, resulting in four to 16 parts per billion (ppb) concentrations in Lake Mead and the Colorado River (EPA, 2000). The NDEP and the SNWA have initiated a collective investigation to locate and clean up perchlorate in the Colorado River system in coordination with the EPA. The primary objectives are to locate the source, the groundwater discharge sources, clean it up, and prevent it from becoming a problem in the future. The EPA has not established concentration levels of perchlorate because it is not considered a water contaminant. However, California’s Department of Health Services and NDEP have established an interim action level of 18 ppb for drinking water. Concentrations lower than 18 ppb are r not considered to pose a health concern for the public, includingInterio and pregnant children e 17 women. All SNWA drinking water has tested at 11 ppbof th 9, 20 pt. or lower2for perchlorate. Average perchlorate values for water samples . De emberintake were 9.5 ppb v collected at their tion n is not aPerchlorateNov regulated under the Federal between June 1999 and August 2000. ajo N ived o Safe Drinking Water Act Nav and thus information is limited regarding its potential health in arch cited 168 how risks but it is known to affect64, the thyroid processes iodine and is used to treat Graves Disease. o. 14 N In March 1998, perchlorate was added to the Contaminant Candidate List as part of the Safe Drinking Water Act due to the concern over potential public health impact, need for additional research in areas of health effects, treatment technologies, analytical methods, and more complete occurrence data. The SNWA identified a major surface flow of perchlorate-laden water from a groundwater discharge point along Las Vegas Wash in late 1999. Other discharge points are being investigated. Kerr-McGee Chemical Company, with the NDEP, and Reclamation as the land management agency, worked together to begin intercepting that surface flow for treatment. This program is now underway and has significantly reduced the amount of perchlorate entering the Las Vegas Wash, Lake Mead, and the Colorado River. This remediation program will continue into the future and will continue to reduce perchlorate contamination in groundwater and Colorado River water in Lake Mead and downstream. In a soon to be published article on contaminants found in Lake Mead fish by Dr. Jim Cizdziel, University Nevada Las Vegas, only one fish sampled of approximately 300 fish tissues sampled for mercury indicated results above the Federal Department of Agriculture’s 1.0 ppm level of concern. During this 1998-1999 investigation for metals COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-17 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 266 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 found in Lake Mead fish tissue, most fish sampled for mercury were less than 0.5 ppm (Pollard, 1999). After reviewing this work, the State of Nevada has decided not to issue any fish consumption advisories for any contaminates for Lake Mead fish (Pohlmann, 1999). The rate and volume of inflow from the Colorado River are major determinants of the limnology of Lake Mead, with minor contributions to volume coming from the Virgin and Muddy rivers and the Las Vegas Wash (see Table 3.5-5). Due to its lower conductivity within Lake Mead, Colorado River flows can be identified through the reservoir. Flows into Lake Mead average approximately 17,900 to 21,400 cfs. During a seven-day controlled flood in 1996, inflows of 44,600 cfs resulted in a three-foot rise in surface elevation. Flows of this magnitude influence reservoir limnology of Lake Mead well into Boulder Basin (LaBounty and Horn, 1997). Table 3.5-5 Hydraulic Inputs for Lake Mead Input Colorado River Virgin River Las Vegas Valley Wash Muddy River Flow (af) 8,800,000 92,000 59,000 29,000 % of Total 98 1 0.60 0.34 ior Inter 17 0 f the pt. o er 29, 2 e TOTAL INPUT 9,000,000 v. D mb 100 ation on Nove jo N Derived from USGS data from October 1975 – September 1976 Nava archived in cited 16864, 14No. The two major outflows from Lake Mead are both in Boulder Basin: Hoover Dam and the SNWA intake. Hoover Dam is operated for flood control, river regulation and power production purposes. The operating elevation for Hoover Dam powerplant ranges from 1083 feet to a maximum elevation of 1221 feet msl. The dam’s four intake towers draw water from the reservoir at approximate elevations 1050 and/or 900 feet msl to drive the generators within the dam’s powerplant. SNWA pumps water from two adjacent intakes located at Saddle Island that operate down to elevations of 1050 feet and 1000 feet msl. Hoover Dam outflows vary on a daily basis from approximately 2000 cfs to 50,700 cfs. Capacity of the SNWA intake is 600 cfs. Despite its much smaller volume, the SNWA intake has been shown to influence deep water currents near the entrance to Las Vegas Bay (Sartoris and Hoffman, 1971). LaBounty and Horn (1997) cite the rarity of complete turnover in Lake Mead due to the great depth (590 feet), and relatively constant temperature gradient. The thermal regime over the period of 1990 through 1996 was characterized by surface temperatures of 14 degrees Celsius (°C) in December and January to over 30°C in August. Seasonal thermoclines range from 50 feet in early summer to 100 feet in late summer. Hypolimnetic temperatures remain near 12°C year-round. Though full reservoir COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-18 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 267 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 turnover seldom occurs, turnover occurs to a depth of approximately 200 to 230 feet in January and February, a sufficient depth for complete mixing in Las Vegas Bay. As with other reservoirs, dam operation exerts a great influence on the water quality and ecology of the system (Thornton, 1990). The hydrodynamics of this large reservoir are complex and not completely understood. Each basin within Lake Mead is ecologically unique, and therefore responds differently to the inflow-outflow regime. Furthermore, the different sources of water entering Lake Mead often retain their identity for substantial distances into the reservoir and do not necessarily mix completely with the rest of the water column (Ford, 1990). This spatial heterogeneity can lead to significant underestimates of actual water retention time, conveyance and fate of materials transported into the reservoir. 3.5.3.2.3 Hydrodynamics of Lake Mead and Boulder Basin The Colorado River, Virgin and Muddy rivers and Las Vegas Wash all form density currents in Lake Mead (Anderson and Pritchard, 1951; Deacon and Tew, 1973; Deacon 1975, 1976, 1977; Baker et al., 1977; Baker and Paulson, 1978). Anderson and Pritchard (1951) conducted a detailed investigation of density currents in 1948-1949 using temperature and TDS relationships to trace the river inflows.terior found that the In They Colorado River flowed along the bottom of the old riverof the in winter 7 channel , 201 (Januaryt. 9 March). The underflow was detectable well v. DepVirginber 2 and at times extended into the m Basin nstrong convergence at the point where river e to Boulder Basin. The underflow created a Natio d o Nov ajoUp-lakeeflown surface water occurred due to v water flowed beneath lake water. chiv of in Na dparallel 64, ar lake water (entrainment) along the boundary of the frictionally induced, flow of ite c 68 14 1 cold river inflow. .This-produced a large circulation cell in the Upper Basin of Lake No Mead, as surface water was pulled up-lake to replace that entrained by the underflow. Hydrodynamics within Las Vegas Bay have also been the subject of research and are particularly important from the standpoint of potential interactions between Las Vegas Wash water and intake water quality. LaBounty and Horn (1997) provide an excellent discussion of flow patterns in this area of Lake Mead. These authors cite unique signatures of both Colorado River water and Las Vegas Wash water that allow mapping of higher conductivity intrusions from Las Vegas Wash into Boulder Basin. Depending on conditions, the intrusion can be measured for over five miles into Lake Mead. Seasonally, the Las Vegas Wash intrusion is deepest in January and February (130 to 200 feet) and shallowest in early spring (33 to 50 feet). Water quality in Las Vegas Wash, and ultimately in Boulder Basin, is heavily influenced by urban runoff, as well as the treated effluent from three major sewage treatment facilities upstream. Historically, flows in this basin drained wetlands, which allowed for natural cooling and nutrient removal. Flows today are warmer and have doubled in volume over the last 15 years, from 110 cfs to 215 cfs (LaBounty and Horn, COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-19 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 268 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 1997). These factors have tended to force the intrusion higher in the water column of Las Vegas Bay. The existence of contaminants in sediments and fish tissue in Las Vegas Bay, and poor water quality has been well documented (LaBounty and Horn, 1996; Roefer et al., 1996; Bevans et al., 1996). LaBounty and Horn (1997) cite the relatively close proximity of the SNWA intake at Saddle Island to potential intrusions of the Las Vegas Wash, and conclude that changes in hydrodynamics of the basin (i.e., due to drought or management actions) are critical considerations in assessing effects of the Las Vegas Wash on drinking water quality. 3.5.3.3 3.5.3.3.1 ENVIRONMENTAL CONSEQUENCES General Effects of Reduced Lake Levels This section presents potential water quality changes in Lake Mead associated with reductions in lake levels, and potential effects of these changes on the concentration of Las Vegas Wash water at SNWA water supply intakes. In addition, this section addresses general limnological changes in Lake Mead that may occur under each r alternative. terio In 7 f he . ointLake29, 201 pt It is important to note that estimates of potentialDe changes ber Mead surface v. elevations are based on system modelingon Section i discussed in vem 3.3. Water quality No Nat modeling has not been conducted as a part of this investigation; however, literature vajo hived on in Na review and assumptions with64, arc Las Vegas Wash mixing in the Boulder Basin ited 68 regard to c under various Lake 14-1 elevations have been used to estimate potential future water Mead No. quality conditions. Results of model runs conducted for this analysis indicate that projections of baseline conditions and each of the interim surplus criteria alternatives indicate increased potential over time for the occurrence of declining Lake Mead surface elevations within and beyond the interim 15-year period, as indicated by the plots of median elevations on Figure 3.5-5. The potential degradation of SNWA intake water is not demonstrated quantitatively in this FEIS, rather the expectation of degradation is based on the assumption that decreasing lake levels, and therefore lake volume and surface area, could result in decreased water quality and, more specifically, increased concentration of Las Vegas Wash inflow at the intake locations. The potential effects associated with Lake Mead elevation declines are described below, and are followed by a tabular comparison of the projected Lake Mead volume and surface area changes under the alternatives and baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-20 1000 2000 1020 1040 1060 1080 1100 1120 1140 1160 1180 1200 1220 2005 2010 2015 2020 3.5-21 Year 2025 2030 2035 Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 2040 2045 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 Baseline Conditions o. 14 N Basin States Alternative Figure 3.5-5 Lake Mead End-of-Year Water Elevations Comparison of Surplus Alternatives to Baseline Conditions th 50 Percentile Values COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 269 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 270 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.5.3.3.1.1 CHAPTER 3 Volume Reduction Reduction in the volume of Lake Mead would likely have effects on lake water quality and, potentially, on water quality withdrawn by SNWA. These effects occur as a result of changes in mixing patterns in Boulder Basin. Given the hydrodynamics of Boulder Basin associated with the relatively confined nature of the embayment, effects of reduction in volume of Lake Mead would likely be disproportionately greater in Boulder Basin than in the lake as a whole. LaBounty and Horn (1997) cite the importance of salinity and thermal gradients in determining the extent of intrusion of the Las Vegas Wash into Boulder Basin. Lower lake volumes could increase the overall salinity of the Boulder Basin, thereby lowering the differential between lake water and inflows of the Las Vegas Wash. This in turn may act to disperse the intrusion, causing a more diffuse flow from Las Vegas Wash, a greater concentration of nutrients and contaminants throughout Boulder Basin, and greater availability of nonpoint contaminants in the vicinity of the SNWA intakes. Clark County’s 208 Water Quality Plan certified by EPA and NDEP, regulates the quality and quantity of discharges from wastewater treatment facilities that flow into Lake Mead. These discharges currently meet standards and will do so into the future (Clark County, 1997). The SNWA is in the process of upgrading its raw water treatment facilities and these state of the art facilities will be able to meet ior any treatment challenges from reduced reservoir levels caused bynter I drought or declines f the 9, 2017 from interim surplus alternatives. pt. o 2 . De ber ion v Novem 3.5.3.3.1.2 Tributary Water at jo NQuality on Nava archived in Lower water surface elevations in Lake Mead could also impact the quality of tributary cited 16864, flows from the Las Vegas Wash, Virgin and Muddy rivers. These effects would be a o. 14 Nchannels, and thus, longer travel times for influent streams. Potential result of longer effects on Lake Mead could include increased temperature due to warmer tributary flows. Higher evaporative losses and greater concentration of salts and contaminants may also occur in tributaries due to longer channels, leading to higher concentrations of pollutants in the Las Vegas Wash, and potentially greater concentrations of contaminants near the SNWA intakes. However, new riparian habitat development near the mouths and in these tributaries would likely develop and would be expected to offset impacts to tributary water quality. Restoration of the Las Vegas Wash wetlands will trap surface and groundwater contaminants, cool return flows and further improve the quality of return flows before it reaches Lake Mead. 3.5.3.3.2 Comparison of Baseline Conditions and Alternatives Section 3.5.3.3.1, above, discussed the general water quality effects that may be expected given reduced Lake Mead surface elevations and volumes. The following sections compare predicted surface elevations, volume, and surface area of Lake Mead under baseline and alternative conditions. This analysis is based on system modeling COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-22 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 271 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 results; specifically the 50 percent (median) probability elevations, as shown on Figure 3.5-5. Characteristics of Lake Mead (elevation, volume, surface area) under baseline and alternative conditions are shown below for four selected years (i.e., years 2016, 2026, 2036 and 2050) within the modeled period, as shown in Table 3.5-6. A comparison of the percentage difference between the alternatives and baseline conditions is shown in Table 3.5-7. It should be noted that median elevations converge with the baseline condition towards the end of the period of analysis, resulting in minimal differences among the alternatives and baseline conditions in the year 2050. 3.5.3.3.2.1 Baseline Conditions Baseline projections indicate a general trend of decreasing Lake Mead surface elevations, volume and surface area over the period of analysis, as shown above on Figure 3.5-5 and in Table 3.5-4. At the end of the interim surplus criteria period, 2016, the median elevation for Lake Mead is 1162 feet msl, a reduction of 15 feet from the surface elevation in 2002. The median baseline elevation in 2050 is 1111 feet msl for a total reduction in the median elevation of 76 feet over the entire period of analysis. This increased potential for lake level reductions would be expected to result r an increased terio in he Ineffects17 the SNWA potential for declining water quality of Lake Mead and associated , 20 on of t 9 ept. under baseline conditions. intake (discussed in Section 3.5.3.3.1, above) over time mber 2 v. D n e Natio d on Nov o ajAlternative 3.5.3.3.2.2 Basin Nav States ive d in 64, arch cite 8 Modeling of the Basin -16 Alternative indicates intermediate reductions in surface . 14States No elevations, surface area and volume compared with baseline conditions in the year 2016 (when the largest differences among the alternatives are seen). The median elevation in year 2016 under the Basin States Alternative is 1143 feet msl, or 1.6 percent lower than baseline conditions in the same year, with reservoir volume approximate 12 percent lower than baseline conditions and volume becoming slightly greater than baseline by the year 2026 and slightly less than baseline in 2036. By the year 2050 no differences between this alternative and baseline conditions are present. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-23 1143.3 1162.1 1145.5 Basin States Flood Control Six States 1124.7 1128.0 1124.7 1125.7 2026 2050 1110.6 1110.6 1110.6 1110.6 2036 1120.7 1120.4 1118.9 1120.5 16.0 17.9 15.8 17.9 2016 13.8 14.1 13.8 13.9 2026 13.4 13.2 13.4 13.4 2036 Volume (maf) 12.5 12.5 12.5 12.5 2050 109.4 120.2 108.1 120.2 2016 99.3 100.7 99.3 99.8 2026 97.5 96.8 97.4 97.6 2036 Surface Area (x 1000 acres) -1.6% 0.00% -1.4% -2.7% -2.7% Flood Control Six States California Shortage Protection 1117.6 1110.6 14.5 13.0 13.1 12.5 -0.2% 0.00% 0.00% 1.4% -1.5% 0.00% 0.00% -10.1 -0.7% -0.8% 3.5-24 -0.3% 0.00% -19.6% -5.0% -0.3% 0.00% -19.0% -6.5% -2.2% 0.00% -15.4% -3.3% -2.2% 0.00% -15.1% -3.9% -0.5% 0.9% -0.5 102.1 -0.1% 0.00% 0.00% -10.6% -0.7% 0.00% 0.00% -9.0% 0.2% -0.1% 0.00% 0.00% -11.7% -0.7% 0.00% 0.00% th 1116.4 Basin States 1131.2 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 1 California 0.00% 96.3 -1.3% 0.00% -1.3% 0.00% -0.2% 0.00% -0.8% 0.00% -0.2 95.9 or 96.3 Shortage Protection 1130.2 1117.9 1117.6 1110.6 14.4 13.2 13.1 12.5 101.7eri96.5 Int e of th 29, 2017 Values shown are median elevations (50 percentile) for each year group. pt. . De ember v ation on Nov N Table vajo hived3.5-7 Modeled in Na Comparisons of Alternatives to Baseline Conditions rc a cited 16864, Volume Change Surface Area Change 1 Elevation Change Alternative o.20164 2026 2036 2050 2016 2026 2036 2050 2016 2026 2036 2050 N 1162.1 2016 Baseline Conditions Alternative Elevation (feet above msl) 1 Table 3.5-6 Modeled Characteristics of Lake Mead Under Baseline and Alternative Conditions AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 93.6 93.6 93.6 93.6 93.6 93.6 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 272 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 273 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.5.3.3.2.3 Baseline Conditions Baseline projections indicate a general trend of decreasing Lake Mead surface elevations, volume and surface area over the period of analysis, as shown above on Figure 3.5-5 and in Table 3.5-4. At the end of the interim surplus criteria period, 2016, the median elevation for Lake Mead is 1162 feet msl, a reduction of 15 feet from the surface elevation in 2002. The median baseline elevation in 2050 is 1111 feet msl for a total reduction in the median elevation of 76 feet over the entire period of analysis. This increased potential for lake level reductions would be expected to result in an increased potential for declining water quality of Lake Mead and associated effects on the SNWA intake (discussed in Section 3.5.3.3.1, above) over time under baseline conditions. 3.5.3.3.2.4 Basin States Alternative Modeling of the Basin States Alternative indicates intermediate reductions in surface elevations, surface area and volume compared with baseline conditions in the year 2016 (when the largest differences among the alternatives are seen). The median elevation in year 2016 under the Basin States Alternative is 1143 feet msl, or 1.6 percent lower than baseline conditions in the same year, with reservoir volume approximate 12 percent ior lower than baseline conditions and volume becoming slightly greaterrthan baseline by Inte 17 the year 2026 and slightly less than baseline in 2036. By f thyear 2050 0 differences the e no pt. o er 29, 2 e present.b between this alternative and baseline conditionsD v. are m n e Natio d on Nov ajoAlternative 3.5.3.3.2.5 Flood Nav Control ive d in 64, arch cite 8 Modeling of the Flood -16 . 14 Control Alternative produces similar surface elevations, surface No area, and volume compared with baseline conditions in the year 2016, with the elevation, surface area and volume becoming slightly greater then baseline by the year 2026 and slightly less than baseline in 2036. By the year 2050 no differences between this alternative and baseline conditions are present. 3.5.3.3.2.6 Six States Alternative Modeling of the Six States Alternative indicates a Lake Mead surface elevation 1.4 percent lower and a volume 10.6 percent lower than baseline conditions in 2016. By the year 2026 and for the remaining period of analysis, differences between baseline conditions and this alternative are within one percent. 3.5.3.3.2.7 California Alternative Modeling of the California Alternative indicates a volume of Lake Mead in the year 2016 that is 19 percent lower than baseline conditions, with the difference decreasing to 6.5 percent and 2.2 percent in the years 2026 and 2036, respectively. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-25 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 274 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.5.3.3.2.8 Shortage Protection Alternative Modeling of the Shortage Protection Alternative indicates similar changes in volume reduction as the California Alternative throughout the period of analysis, with volume 19.6 percent lower than baseline conditions in 2016, 6.5 percent lower in 2026 and 2.2 percent lower in 2036. 3.5.3.3.2.9 Summary of Changes in Lake Mead Volume and Elevation Tables 3.5-6 and 3.5-7 summarize modeled changes in Lake Mead surface elevation, area, and volume under each of the alternatives as compared with baseline conditions. With the exception of the Flood Control Alternative, each of the alternatives indicate an increase potential for lower surface elevations, surface area and lake volume. These difference are most pronounced in year 2016, the end of the interim surplus criteria period. The greatest differences compared with baseline conditions are associated with the California and Shortage Protection alternatives, with intermediate differences indicated by the Basin States and Six States alternatives. 3.5.4 WATER QUALITY BETWEEN HOOVER DAM AND SOUTHERLY r INTERNATIONAL BOUNDARY terio n the I , 2 17 . of contaminants0in the Lower There have been concerns from the EPA and others pt De about er 29 n v.SIB. ovemb there is little site specific Colorado River between Hoover Dam and the atio N However, ajo N USGS on study of mercury and other data from this segment of thev Na river. Ahived (1995) contaminants foundd in and4, arc located in the Yuma Valley area concluded that in fish 6 wildlife cite 1 8 mercury is not a problem.6 14No. The above study also indicates that selenium is also not a problem for fish and wildlife. Selenium in Colorado River water in the Yuma Valley had a median value of less than one micrograms per liter (μg/l). This research also confirms what other previous selenium studies have concluded: selenium in the LCR and its biota remains below the DOI level of concern of five μg/l. A 1986-1987 study by the USGS indicated a finding of 3.4 μg/l or less for dissolved selenium at several sites in the Lower Colorado River (USGS, 1988). Department of Interior’s Pre-reconnaissance Investigation Guides (1992) reported similar findings of less than 3.4 μg/l in Colorado River water at Pilot Knob. In the 1995 USGS study of the Yuma area, measured selenium in 18 water samples averaged 1.72 μg/l, with a maximum of 8.0 μg/l and a minimum of less than 1.0 μg/l. Nine of the 18 measurement results were reported to be less than 1.0 μg/l. Currently there are no state fish consumption advisories for mercury, selenium or any other contaminants on the Lower Colorado River (Ketinger, 2000). Water quality studies will continue in this segment of the river during the 15-year period of proposed interim surplus criteria. None of the action alternatives are anticipated to increase concentrations of contaminants beyond the noted limits. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.5-26 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 275 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.6 RIVERFLOW ISSUES 3.6.1 INTRODUCTION This section considers the potential effects of interim surplus criteria on three types of releases from Glen Canyon Dam and Hoover Dam. The Glen Canyon Dam releases analyzed are those needed for restoration of beaches and habitat along the Colorado River between the Glen Canyon Dam and Lake Mead, and for a yet to be defined program of low steady summer flows to be provided for the study and recovery of endangered Colorado River fish, in years when releases from the dam are near the minimum. The Hoover Dam releases analyzed are the frequency of flood releases from the dam and the effect of flood flows along the river downstream of Hoover Dam. 3.6.2 BEACH/HABITAT-BUILDING FLOWS The construction and operation of Glen Canyon Dam has caused two major changes related to sediment resources downstream in Glen Canyon and Grand Canyon. The first is reduced sediment supply. Because the dam traps virtually all of the incoming sediment from the Upper Basin in Lake Powell, the Colorado River is now released from the dam as clear water. The second major change is the reduction in the high ior Inter 17 releases. water zone from the level of pre-dam annual floods to the level of powerplant f the 9, 20 Thus, the height of annual sediment deposition and pt. o hasr been reduced. erosion 2 De . be on v N em atipreparation ovthe Operation of Glen Canyon During the investigations leadingo N on of aj to the Nav1995b),hived Dam Final EIS (Reclamation, in arc the relationships between releases from the dam c ted 16864, and downstreamisedimentation processes were brought sharply into focus, and flow 4patterns designed . 1 Noto conserve sediment for building beaches and habitat (i.e., beach/habitat-building flow, or BHBF releases) were identified. The BHBF releases are scheduled high releases of short duration that exceed the hydraulic capacity of the powerplant. Such releases were presented as a commitment in the ROD (Reclamation, 1996e) for the Operation of the Glen Canyon Dam FEIS, at a then-assumed frequency of one in five years. In addition to the BHBF releases described above that exceed the hydraulic capacity of the Glen Canyon Powerplant, the Operation of Glen Canyon Dam FEIS identified the need for Beach/Habitat Maintenance Flow releases which do not exceed the hydraulic capacity of the powerplant. These flows were designed to prevent backwater habitat from filling with sediment and to reduce vegetation on camping beaches in years between BHBFs. BHBF releases and Beach/Habitat Maintenance Flows serve as a tool for maintaining a mass balance of sediment in Glen Canyon and Grand Canyon. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 276 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.6.2.1 METHODOLOGY The frequencies at which BHBF releases from Glen Canyon Dam would occur under baseline conditions and under operation of the interim surplus criteria alternatives were estimated through the use of modeling as described in Section 3.3. The model was configured to simulate BHBF releases by incorporating the BHBF triggering criteria (contained in Section 3.6.2.2) into the Glen Canyon Dam operating rules. The model was also configured to make no more than one BHBF release in any given year. 3.6.2.2 AFFECTED ENVIRONMENT Sediment along the Colorado River below Glen Canyon Dam is an important and dynamic resource which affects fish and wildlife habitat along the river, creates camping beaches for recreation, and serves to protect cultural resources. Except for remnants of high river terraces deposited prior to the closure of Glen Canyon Dam, the now limited sediment supply that exists along the river channel is affected by dam operations. ior er Since construction of Glen Canyon Dam, the measured suspended tsediment load (sand, he In million tons per 017 silt, and clay) at Phantom Ranch (in the Grand Canyon)of t pt. averages 11, 2 29 . De the Little year. Most of this load comes from the PariavRiver andember Colorado River. ion N v Flash floods from other side canyons at contributeo the sediment supply ajo N alsoed on to iv (Reclamation, 1995b).in Nav The suspended sediment load is sporadic in occurrence, arch ited 6864, releases and tributary inputs. c depending on Glen Canyon Dam -1 14 No. Beneficial sediment mobilization and deposition below Glen Canyon Dam depends on the interaction of two occurrences for full effectiveness: the addition of sediment to the river corridor and BHBF releases. The higher energy of BHBF releases mobilizes suspended and riverbed-stored sand and deposits it as beaches in beach and shoreline areas. Once a BHBF release has been made, additional sediment supply from tributary inflows is needed before subsequent BHBF releases are fully effective in promoting further beach and sandbar deposition along the river. Subsequent to the ROD cited above, the representatives of the AMP further refined specific criteria under which BHBFs would be made. The criteria provide that under the following two triggering conditions, BHBF releases may be made from Glen Canyon Dam: 1. If the January forecast for the January-July unregulated spring runoff into Lake Powell exceeds 13 maf (about 140 percent of normal) when January 1 content is greater than 21.5 maf; or 2. Any time a Lake Powell inflow forecast would require a monthly powerplant release greater than 1.5 maf. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 277 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Research concerning the relationships among dam operations, downstream sediment inflow, river channel and sandbar characteristics, and particle-size distribution along the river is ongoing. 3.6.2.3 ENVIRONMENTAL CONSEQUENCES The effects of the interim surplus criteria alternatives on BHBF releases from Glen Canyon Dam were analyzed in terms of the yearly frequency at which BHBF releases could be made. Specifically, the frequency was indicated by the occurrence of one or both of the triggering criteria cited above, during a calendar year. The following discussion presents probability of occurrence under baseline conditions, and then compares the probability of BHBF releases under each interim surplus criteria alternative with the baseline conditions. Figure 3.6-1 shows the probabilities that BHBF releases could be made under baseline conditions and the action alternatives. The plots show that the probabilities will decrease over the first decade to an irregular range of approximately 10 to 15 percent or lower, which is maintained until a slight rising trend appears in the last 15 years of the period of analysis. The trends result from the interaction of various factors, including projected increases in depletions by the Upper Division states and the irequirements for or Inter 17 equalization of storage in Lakes Powell and Mead. The operational parameter most f the 9 20 directly comparable to the plotted relationships is eptfuture median,water level of Lake the . o D level of er 2 Powell. As can be seen on Figure 3.3-6,on v. the medianovembthe reservoir is projected to ati nN recover somewhat in the last vajyears of the period of analysis. This correlates to the 15 o N ed o a hiv slight rise in BHBF d in N probabilities in the final 15 years. release , arc cite 16864 14Table 3.6-1 summarizes the BHBF release probabilities during the interim period and No. the subsequent period to 2050, based on the data plotted in Figure 3.6-1. The table reflects the higher average probability during the interim period than during the succeeding period ending in 2050. Table 3.6-1 Probabilities of BHBF Releases from Glen Canyon Dam Percent of Time That Conditions Needed for BHBF Releases Would Occur at Lake Powell Period Baseline Condition Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative Through 2016 15.9% 14.8% 15.9% 14.9% 13.0% 13.0% 2017-2050 13.5% 13.4% 13.5% 13.4% 13.2% 13.2% COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-3 0% 2000 10% 20% 30% 40% 50% 60% 70% 2005 2010 2015 2020 3.6-4 Year 2025 2030 2035 2040 ior Inter 17 e of th 29 0 Baseline Conditions , 2 pt. States Alternative . De Basinmber v Flood ation on Nove Control Alternative Six States Alternative jo N ved Nava archi California Alternative in Shortage Protection Alternative ited 6864, c -1 14 No. Figure 3.6-1 Lake Powell Releases Probability of Occurrence of BHBF Flows COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Probability of Occurrence AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2045 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 278 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 279 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.6.2.3.1 Baseline Conditions During the interim period, the average probability under baseline conditions that BHBF releases could be made in a given year is approximately 15.9 percent, which is equivalent to about one year in six. During the subsequent period ending in 2050, the average probability is approximately 13.5 percent, which is equivalent to about one year in seven. The reduction in probability after 2015 under baseline conditions results from the fact that with time, the Lake Powell water level will probably decline because of increased Upper Basin depletions, as illustrated in Section 3.3. This water level decline would gradually reduce the probability that the BHBF triggering criteria would occur. 3.6.2.3.2 Basin States Alternative During the interim period, the average probability under the Basin States Alternative that BHBF releases could be made in any single year is approximately 14.8 percent, which equates to approximately one year in seven. During the subsequent period ending in 2050, the average probability is approximately 13.4 percent, which is equivalent to about one year in seven. ior Inter 17 f the During the interim period, the average probability under the Flood9, 20 Alternative pt. o er 2 Control e that BHBF releases could be made in any singleD isemb n v. ioin six. year v approximately 15.9 percent, t No which equates to approximately jone year o Na ed onDuring the subsequent period ending va is approximately 13.5 percent, which is equivalent to Na in 2050, the average probability rchiv ed in itseven. 6864, a about one year c in -1 o. 14 N 3.6.2.3.4 Six States Alternative 3.6.2.3.3 Flood Control Alternative During the interim period, the average probability under the Six States Alternative that BHBF releases could be made in any single year is approximately 14.9 percent, which equates to approximately one year in seven. During the subsequent period ending in 2050, the average probability is approximately 13.4 percent, which is equivalent to about one year in seven. 3.6.2.3.5 California Alternative During the interim period, the average probability under the California Alternative that BHBF releases could be made in any single year is approximately 13.0 percent, which equates to approximately one year in eight. During the subsequent period ending in 2050, the average probability is approximately 13.2 percent, which is equivalent to about one year in eight. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 280 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.6.2.3.6 Shortage Protection Alternative During the interim period, the average probability under the Shortage Protection Alternative that BHBF releases could be made in any single year is approximately 13.0 percent, which equates to approximately one year in eight. During the subsequent period ending in 2050, the average probability is approximately 13.2 percent, which is equivalent to about one year in eight. 3.6.3 LOW STEADY SUMMER FLOW 3.6.3.1 AFFECTED ENVIRONMENT During preparation of the Operation of Glen Canyon Dam FEIS, it was hypothesized that steady flows with a seasonal pattern may have a beneficial effect on the potential recovery of special status fish species down stream of Glen Canyon Dam. Accordingly, development of an experimental water release strategy was recommended by the Service to achieve steady flows when compatible with water supply conditions and the requirements of other resources. The strategy included developing and verifying a yet to be defined program of experimental flows which would include providing high steady flows in the spring and low steady flows in summer and fall during water years rior when a volume of approximately 8.23 maf is released from he Inte Glen Canyon Dam. This t 017 strategy, commonly referred to as the low steady summerfflow program, was contained pt. o er 29, 2 . De in the Final Biological Opinion on the Operation of Glenmb ion v Nove Canyon Dam (Service, N t December 1994c), and recognized in a ROD for the Operation of Glen Canyon Dam vajo theved on i FEIS (USDI, 1996).d in Na arch cite 16864, 143.6.3.2 ENVIRONMENTAL CONSEQUENCES No. The ability to test the low steady summer flow release strategy at Glen Canyon Dam according to the ROD could be affected by the implementation of interim surplus criteria. This matter was investigated by analyzing the model releases from Glen Canyon Dam to determine the probabilities at which minimum releases of 8.23 maf per water year would occur. Figure 3.6-2 shows the annual probabilities of minimum releases from Glen Canyon Dam during the period of analysis. Note that the first year plotted is 2003, since 2003 would be the first complete water year (October 1, 2002 through September 30, 2003) during the interim period. The plots show that the probabilities increase through 2023, from approximately 20 to 25 percent to approximately 60 percent, which is maintained until another increase to 67 percent occurs during the last 15 years of the analysis. The trends result from the interaction of various factors that affect annual releases from Glen Canyon Dam, including projected increases in depletions by the Upper Division states and the requirements for equalization of storage in Lakes Powell and Mead. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-6 0% 2000 10% 20% 30% 40% 50% 60% 70% 2005 2010 2015 2020 3.6-7 Water Year 2025 2030 2035 2040 Shortage Protection Alternative California Alternative Six States Alternative 2045 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc Baseline Conditions cite 168 Basin States Alternative o. 14 Flood Control Alternative N Figure 3.6-2 Lake Powell Releases Probability of Approximately 8.23 maf Annual Release COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Probability of Occurrence AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 281 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 282 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.6-2 summarizes the probabilities that minimum releases would occur during the interim period and the subsequent period to 2050, based on data plotted in Figure 3.6-2. Probabilities are summarized by water year because releases from Glen Canyon Dam are accounted for by water year under provisions of the LROC. The results indicate that under baseline conditions, the probability of 8.23 maf annual releases from the dam is approximately 38.2 percent during the interim period and 61.6 percent during the subsequent period ending in 2050. The probabilities under all alternatives are similar to those under baseline conditions after 2006. Under the Flood Control Alternative, the probability is approximately the same as for baseline conditions, as shown on Table 3.62. The probabilities under the remaining four interim surplus criteria alternatives during the interim period are one to two percent less than under baseline conditions. During the subsequent period through 2050, the probabilities resulting from the remaining four surplus criteria would be one to two percent higher than under baseline conditions. Table 3.6-2 Probability of Minimum Glen Canyon Dam Releases (Annual Releases of 8.23 maf) Period (Water Years) Baseline Condition Basin States Alternative Flood Control Alternative Six States Alternative California Alternative ior Inter 17 Through 38.2% 36.3% 38.4% 36.2%he 35.8% 0 ft 2016 pt. o er 29, 2 e v. D 61.9%b m 2017-2050 61.6% 61.9% 61.6% 62.2% ation on Nove N ajo is basedd v Note: The "water year" on whichNaaccounting hive extends from October 1 to September 30. this d in 64, arc cite 168 14No. 3.6.4 Shortage Protection Alternative 36.3% 62.1% FLOODING DOWNSTREAM OF HOOVER DAM Under the BCPA, flood control was specified as the project purpose having first priority for the operation of Hoover Dam. Subsequently, Section 7 of the Flood Control Act of 1944 established that the Secretary of War (now the Corps) will prescribe regulations for flood control for projects authorized, wholly or in part, for such purposes. The Los Angeles District of the Corps published the current flood control regulations in the Water Control Manual for Flood Control, Hoover Dam and Lake Mead Colorado River, Nevada and Arizona (Water Control Manual) dated December 1982. The Field Working Agreement between Corps and Reclamation for the flood control operation of Hoover Dam and Lake Mead, as prescribed by the Water Control Manual, was signed on February 8, 1984. The flood control plan is the result of a coordinated effort between the Corps and Reclamation; however, the Corps is responsible for providing the flood control regulations and has authority for final approval. The Secretary is responsible for operating Hoover Dam in accordance with these regulations. Any deviation from the flood control operating instructions must be authorized by the Corps. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 283 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 This analysis addresses the flooding that occurs along the Colorado River below Hoover Dam. The evaluation focuses on the change in the probability that various “threshold” flows would be released from Hoover, Davis and Parker Dams. A threshold flow rate is one at which flood damages have been found to begin to occur along the river. The analysis is not limited to dam releases made expressly in connection with flood control operation, but also includes releases made for water supply and power generation purposes. For example, power generation requirements can cause releases from Hoover Dam to exceed 19,000 cfs, with such releases being regulated in Lake Mohave downstream. In addition, the analysis presents data on land use and anticipated flood damages that were developed by the Los Angeles District Corps of Engineers in the Review of Flood Control Regulations, Colorado River Basin, Hoover Dam, July 1982 (Corps, 1982). 3.6.4.1 AFFECTED ENVIRONMENT Historical flows downstream of Hoover Dam have caused flood damages at various points along the lower Colorado River. A key threshold level was established as a result of flooding that occurred in 1983 when uncontrolled releases occurred over the Hoover Dam spillways. The high Colorado River flows caused damages primarily to encroachments in the Colorado River floodplain. In addition, several ilower thresholds or Inter subsections. that are significant along various reaches are evaluated infthe e th following017 t. o 9, 2 Dep Act) originated from .(Floodwaymber 2 v The Colorado River Floodway Protection Act e ation othe flood. Nfollowing n Nov The Floodway Act called for Congressional hearings held inajo 1983 d av hive the establishment ofd ifederally declared floodway from Davis Dam to the SIB. The anN , arc 4 cite 168 either a 1-in-100 year river flow consisting of controlled floodway is to accommodate6 41 releases and tributary inflow, or a flow of 40,000 cfs, whichever is greater. As No. discussed in Section 3.3.1, certain flood release rates from Hoover Dam are required depending on flood flow into Lake Mead and the amount of available storage space. Estimates of development in the flood plains below Hoover Dam were last made by the Corps based on 1979 data (Corps, 1982). These data are presented in Table 3.6-3. 3.6.4.1.1 Hoover Dam to Davis Dam Critical flood flows for the reach between Hoover Dam and Davis Dam are 19,000 cfs, 28,000 cfs, 35,000 cfs, 43,000 cfs, and 73,000 cfs. 3.6.4.1.2 Davis Dam to Parker Dam The river is within levees for most of the reach from Davis Dam to Parker Dam. Historical flood flows have caused damage to some of the bank protection. Minor damage begins to occur at flows of 26,000 cfs. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 284 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.6-3 1 Development in Flood Plains Between Hoover Dam and SIB, 1979 Data (Number of structures unless otherwise noted) Flood Flow (cfs) 100,000 Mobile Homes Residential Commercial/ Public/ Industrial Semipublic Agriculture (acres) Recreation 5 Facilities 1,609 1,457 74 70 55,089 278 71,000 2 758 786 54 66 15,861 277 48,000 3 164 198 13 10 2,671 277 38,000 4 101 138 4 6 176 232 17 44 1 0 90 201 28,000 1 Corps of Engineers, Colorado River Basin Hoover Dam, Review of Flood Control Regulations. Final Report, July 1982. Table C-1. 2 78,000 cfs at Needles. 3 50,000 cfs at Needles. 4 40,000 cfs at Needles. 5 Recreation facilities are primarily boat docks that would sustain significant damage with high flows. ior Inter 17 he Critical flood flows for the reach between Hoover Dam of t Davis9, 20are 19,000 cfs, pt. and er 2 Dam De b 28,000 cfs, 35,000 cfs, 43,000 cfs, and 73,000.cfs. ion v Novem at on ajo N 3.6.4.1.4 Davis Damin Nav Dam ived to Parker rch a cited 16864, The river is within levees for most of the reach from Davis Dam to Parker Dam. 14No. 3.6.4.1.3 Hoover Dam to Davis Dam Historical flood flows have caused damage to some of the bank protection. Minor damage begins to occur at flows of 26,000 cfs. 3.6.4.1.5 Parker Dam to Laguna Dam Below Parker Dam, significant damage to permanent homes has occurred during releases within the flood operation criteria. This area has been further developed since the flood operations in 1983. Minor damage begins at 19,000 cfs along the Parker Strip (the reach of river between Parker Dam and the town of Parker, Arizona). Backwater regions, which function as wildlife refuges and recreational areas, accumulated sediment, and in some cases, became isolated from the Colorado River. Historical flood flows have also resulted in damage to infrastructure of government agencies. 3.6.4.1.6 Laguna Dam to SIB Below Laguna Dam, the banks of the Colorado River are not protected. Historical flood flows have resulted in significant damage to the banks. Associated increases of groundwater level in the Yuma area have also resulted in some lands becoming water logged and caused drains to cease functioning. During the scoping process for this COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 285 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 DEIS, a letter from the Yuma County Water Users’ Association states that “[o]ur landowners are harmed by such releases, particularly should the flood control releases be required to go beyond the 19,000 cubic feet per second Hoover release level" (Pope, 1999). The letter indicates that a flood control release of 28,000 cfs or greater could result in upwards of $200 million in damages to the Yuma area. Other injured parties could include the City of Yuma, the County of Yuma, Cocopah Indian Tribe, the Gila Valley, Bard Irrigation District, and the Quechan Indian Tribe. Additional flows of concern include: • Laguna Dam south to Pilot Knob: 9,000 cfs is the threshold value. Flows of 10,000 cfs to 11,000 cfs impact leach fields of trailer parks located within levees. • Pilot Knob to SIB: 15,000 cfs is a threshold value. Above that level, high groundwater, localized crop damage and damage to the United States Bypass Drain occur. 3.6.4.2 ENVIRONMENTAL CONSEQUENCES rior The effects of the interim surplus criteria on flood flows weree Inte by7 h analyzed determining . of t r 2 reach 1 the probabilities that releases from Davis and Parker Dams would 9, 20or exceed ept e certain flow rates that have been found to be v. D for damages. In addition, the n thresholdsemb o atireleases of various magnitudes would be made Nov analysis addressed the probabilitiesN on jo that Nava archived flood control releases discussed in from Hoover Dam corresponding to the required in , cited 168 Hoover Dam. The release probabilities were determined Section 3.3.1.2, Operation of64 from results ofNo. 14 river system modeling described in Section 3.3. The results of the analysis are shown in Table 3.6-4. The results portrayed on Table 3.6.3 show that except for the Flood Control Alternative, the action alternatives would reduce the probability of flows at or above the damage thresholds. The Corps estimated the likely damage to development based on the 1979 land use data (Corps, 1982). These data are presented in Table 3.6-5. The data on direct, physical damages presented in Table 3.6-5 are based on simultaneous flooding along all reaches of the river from Hoover Dam to the SIB. The data show that damages increase much more rapidly than the size of the flow. For example, a 48,000-cfs flow has 15 times the impact of a 22,000-cfs flow, while the flow increases by only 2.2 times. A 48,000 cfs flow has a less than one-in-500 probability of occurring in any one year, while a 22,000 cfs flow has a greater than one-in-20 probability of occurring in any one year under all alternatives. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 286 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.6-4 Discharge Probabilities from Hoover, Davis and Parker Dams Percent of Years With Flows Greater Than or Equal to Discharge Release Point Discharge 1 (cfs) Baseline Basin States Conditions Alternative Flood Control Alternative California Alternative Six States Alternative Shortage Protection Alternative Years 2002 to 2016 Hoover Dam 19,000 20.8 18.8 21.2 16.3 18.6 16.9 Hoover Dam 28,000 7.5 7.2 7.7 5.5 7.1 5.8 Hoover Dam 35,000 2.1 2.0 2.1 1.6 2.0 1.7 Hoover Dam 40,000 0.2 0.2 0.2 0.2 0.2 0.2 Hoover Dam 73,000 0.0 0.0 0.0 0.0 0.0 0.0 Davis Dam 26,000 8.6 8.1 9.1 7.0 8.0 7.1 Parker Dam 19,500 10.4 9.4 11.3 7.8 9.3 8.0 14.6 14.1 14.9 13.9 14.1 13.8 3.8 3.6 0.9 0.8 0.2 0.1 0.0 0.0 4.6 4.5 5.7 5.6 Years 2017 to 2050 Hoover Dam 19,000 ior Hoover Dam 35,000 0.9 1.7 0.9 0.8 Inter 17 he . ft 9, 0 Hoover Dam 40,000 0.2 0.1 pt0.2o er 20.1 2 e v. D vemb Hoover Dam 73,000 0.0 0.0 0.0 ation on No0.0 ajo N iv4.6d Davis Dam 26,000 4.8 5.0 4.4 e Nav d in 64, arch 5.7 Parker Dam 6.1 5.6 ite c19,500 168 5.9 4.1 Average monthly No discharge Hoover Dam 28,000 4.0 3.8 4.2 3.7 1 Table 3.6-5 Estimated Flood Damages Between Hoover Dam and the SIB 1 (1979 level of development and 2000 price level ) Flood Flow (cfs) 100,000 2 71,000 3 48,000 4 38,000 22,000 Flood Damages $201,000,000 $ 55,700,000 $ 9,210,000 $ 1,550,000 $ 610,000 1 Corps of Engineers, Colorado River Basin Hoover Dam, Review of Flood Control Regulations. Final Report, July 1982. Table C-5. Adjusted from June 1978 to March 2000 price level by Consumer Price Index-all Urban Consumers. (June 1978 is 65.2, March 2000 is 167.8, Adjustment factor: 2.57.) 2 78,000 cfs at Needles 3 50,000 cfs at Needles 4 40,000 cfs at Needles COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.6-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 287 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.7 AQUATIC RESOURCES 3.7.1 CHAPTER 3 INTRODUCTION The analyses presented in this section consider two specific issues associated with aquatic resources. These issues are potential effects to Lake Mead and Lake Powell aquatic species habitat and potential effects to sport fisheries at Lake Powell, Lake Mead, and the Colorado River between Lake Powell and Lake Mead. The interim surplus criteria are not expected to result in any changes to aquatic resources below Hoover Dam. 3.7.2 LAKE HABITAT The primary lake habitats identified for potential affect within the project area include Lake Powell and Lake Mead. Other reservoirs downstream of Lake Mead (Lake Mohave and Lake Havasu) are not expected to be affected by the proposed interim surplus criteria because operation of the system keeps lake levels at specified target elevations to facilitate power generation and water deliveries (Reclamation, 2000). Native Colorado River fishes have not fared well in the reservoirs. Non-native fish ior Inter well-established species, which prey on and compete with native species, havee f th become 017 in both lakes. While some native species may spawntwithin the 29, 2 p . o er reservoirs and others De b have young that drift into the lakes, predation . competition is believed to eliminate ion vand Novem at precludes their survival and recruitment. A young native fish from the reservoirs and ed on ajo N NavRiverrchiv is presented in Section 3.8, Special-Status discussion of natived in Colorado a fishes cite 16864, Species. 43.7.2.1 No. 1 METHODOLOGY Existing literature was reviewed to determine the historic and current status of fish assemblages in Lake Powell and Lake Mead. Literature reviewed included recent publications and draft documents on the operations at Lake Powell and Lake Mead, biological assessments, fish management plans, and biological opinions. Investigation into critical lake elevations, water quality, and temperature limits were made based on the fish species known to inhabit these lakes, including the use of these lakes by endangered species. Because no “threshold” lake elevations associated with significant adverse effects on lake habitat were identified for any of the fish species, the use of system modeling relied upon a comparison of general reservoir surface elevation trends under baseline conditions and the alternatives, shown in Figures 3.3-6 and 3.3-13. A qualitative analysis of potential lake habitat changes was made by comparing the differences between lake level trends under baseline conditions and the various alternatives. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 288 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.7.2.2 AFFECTED ENVIRONMENT 3.7.2.2.1 CHAPTER 3 Lake Powell Aquatic habitat in Lake Powell is a result of the lake’s physical and geographical characteristics. Lake Powell has a surface area of 255 square miles and contains up to 24.3 maf of active storage. At full pool, depth of the reservoir near the dam is 561 feet. The thermocline (the boundary layer between a strata of colder and warmer water) changes seasonally, but below approximately 150 feet deep, the cold hypolimnion (a low oxygen, low light, deep water layer of the lake) is consistently maintained due to thermal and chemical properties. Lake Powell exhibits a trophic gradient from the shallow productive inflows where nutrients and sediments are delivered by rivers, to the clear nutrient-poor water by the dam. As the reservoir gradually shallows moving away from the dam, the depth and extent of the thermocline and hypolimnion change. Lake elevations change from year to year depending on numerous factors, including Upper Basin runoff. The clear water reservoir offers habitat beneficial to non-native fish. Generally, the reservoir is oligotrophic (characterized by low dissolved nutrients and organic matter); deep, clear, and low in chlorophyll abundance (NPS, 1996). Non-native fish species became established by intentional and unintentional ior Inter 17 introductions. Largemouth bass and crappie populations were stocked initially and 0 f the 9 Both subsequently proliferated to provide the bulk of the pt. o fisheries. , 2 species have sport e r2 v. D v for be declined in recent years due to lack of habitat structure emyoung fish. Filling, o ation oin changing habitat that eliminated most N fluctuation, and aging of the reservoir resulted n N vajo hived of the vegetation and favored different species. The habitat change led to the in Na arc ited 6864,and striped bass, presently the two dominant predator c introduction of smallmouth bass -1 o. 14 species in the reservoir, with striped bass being the most dominant. Threadfin shad N were introduced to provide an additional forage base and quickly became the predominant prey species (NPS, 1996). Other species common in Lake Powell include walleye, bluegill, green sunfish, carp and channel catfish. Species that occur in the reservoir, but that are mainly associated with tributaries and inflow, include fathead minnow, mosquitofish, red shiner and plains killifish (NPS, 1996). Table 3.7-1 lists fish species present in the project area. Native fish species were displaced by habitat loss and alteration associated with construction and operation of mainstream dams and reservoirs, as well as competition with and predation by introduced non-native species. Bonytail is the native species believed to be in the most peril of imminent extinction because they are virtually eliminated in the Upper Basin. Bonytail were reported in Lake Powell soon after closure of Glen Canyon Dam; however, annual gill-net surveys conducted by the Utah Department of Wildlife Resources have failed to produce any bonytail in the last 20 years. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 289 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.7-1 Fish Species Present in the Project Area Species Black bullhead Black crappie Bluegill Bluehead sucker Bonytail Brown Trout Carp Channel catfish Colorado pikeminnow Fathead minnow Flannelmouth sucker Green sunfish Humpback chub Largemouth bass Mosquitofish Northern pike Rainbow trout Razorback sucker Red shiner Roundtail chub Smallmouth bass Speckled dace Spotted sculpin Striped bass Threadfin shad Walleye Scientific Name Ictalurus melas Pomoxis nigromaculatus Lepomis macrochirus Catastomus discobolus Gila elegans Salmo trutta Cyprinus carpio Ictalurus punctatus Ptychocheilus lucius Pimephales promelas Catostomus latipinnis Lepomis cyanellus Gila cypha Micropterus salmoides Gambusia affinis Esox lucius Oncorhynchus mykiss Xyrauchen texanus Notropis lutrensis Gila robusta Micropterus dolomieui Rhinichthys osculus Cottus bairdi Morone saxatilis Dorosoma petenense Stizostedion vitreum Origin Invading sport fish Introduced sport fish Invading sport fish Native to Colorado River Native to Colorado River Introduced sport fish Invading fish Invading sport fish Native to Colorado River Invading forage fish Native to Colorado River Invading fish Native to Colorado River Introduced sport fish Invading forage fish Invading sport fish Introduced sport fish Native to Colorado River Invading forage fish Native to Colorado River Introduced sport fish Native to Colorado River Native to Colorado River Introduced sport fish Introduced forage fish Invading sport fish ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. Other native species that may still persist in Lake Powell include the Colorado pikeminnow and humpback chub. Although there have been no reports of Colorado pikeminnow in the lake since 1977, they are believed to still inhabit the Colorado River inflow area. Very few humpback chub have been found in Lake Powell and it is presumed that they are not present in the lake at this time; however, unidentified chub species were collected by seines and light traps in the Colorado River inflow area (NPS, 1996). Small numbers of razorback suckers have persisted in Lake Powell since the closure of Glen Canyon Dam, occurring mainly near the inflow of the San Juan River. Flannelmouth suckers are probably the only native fish to inhabit the main body of Lake Powell in detectable numbers. However, there has been a declining trend in population size and reproductive recruitment has not been documented. Additional discussion of special-status fish species is included in Section 3.8. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 290 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.7.2.2.2 CHAPTER 3 Lake Mead Lake Mead has a surface area of 245 square miles and a storage capacity of 26 maf. Over two-thirds of the volume of Lake Mead remains at 55°F (13°C) throughout the year, resulting in a constant, cool discharge at Hoover Dam (USBR, 1996d). At full pool, depth of the reservoir near the dam is approximately 550 feet. Because of its physical similarity to Lake Powell, the limnological characteristics of Lake Mead are also similar. The thermocline changes seasonally and a cold hypolimnion is consistently maintained due to thermal and chemical properties. Surface elevations change from year to year depending on numerous factors, including Upper Basin runoff. The clear water reservoir offers habitat beneficial to non-native fish. Native fish species were displaced by habitat loss and alteration associated with construction and operation of mainstream dams and reservoirs, as well as competition and predation with introduced non-native species. Razorback sucker, federally listed as an endangered species, is the only native species that maintains a remnant population in Lake Mead (USBR, 1996a,b). Non-native fish species became established by intentional and unintentional introductions. Introduced fish species found in Lake Mead include largemouth bass, ior Inter carp (USBR, striped bass, rainbow trout, channel catfish, crappie, threadfine f th shad and017 1996). Bonytail populations are supported by specific. management,activities designed pt o er 29 2 De to re-establish this species in Lake Mohave. v. emb ion Remnantvpopulations of these species exist at No Havasu and groups such as the on jo Mohave and Lake downstream of Lake Mead invLake N Na a archived n Native Fish Wok Group (NFWG) and Lake Havasu Fishery Improvement Project ted i cicurrently6864, in activities conducted under Section 7(a)(l) of the (HAVFISH) are -1 engaged o. 14 ESA to aid in the conservation and recovery of these species in the lower Colorado N River Basis (USBR, 1999). Releases from Lake Mead are the predominant influence on inflows to two other reservoirs, Lake Mohave and Lake Havasu. Operations at Lake Mead typically keep lake elevations at the downstream reservoirs at specific target elevations to facilitate power generation and water deliveries. The operation of Lake Mohave through 2002 is anticipated to limit reservoir fluctuations as a measure to assure that potential impacts to razorback sucker will be minimized during the spawning season (USBR, 1996). 3.7.2.2.3 General Effects of Reservoir Operation Lake habitat in both Lake Powell and Lake Mead consists primarily of deep, clear, open water habitats with a cold hypolimnion that is consistently maintained due to thermal and chemical properties. The habitat found in these lakes is drastically different from the riverine habitat that existed prior to the construction of the dams, and is more suitable for non-native species than native species. Non-native fish species were introduced into the lakes, and subsequently established naturally reproducing populations. Habitat changes resulting from fluctuating lake levels have favored COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 291 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 introduced species tolerant of the conditions and temperatures found in the lakes. These species are able to reproduce in the lakes and are not expected to be affected by fluctuating lake levels. In Lake Powell for example, striped bass have experienced “unprecedented natural reproduction and survival” that allowed them to become “the most numerous sport fish and dominate the fish community of Lake Powell” (NPS, 1996). The ability of native species to adapt to the lake habitat is limited mainly by the decreased survival of eggs and the lack of recruitment of young individuals into the adult population. The primary reason for low recruitment of native fish is predation of eggs and young by the established populations of non-native species. In some cases, nutrition may also influence recruitment (Horn, June 2000). 3.7.2.3. ENVIRONMENTAL CONSEQUENCES There are no specific “threshold” lake levels that are definitive for evaluation of potential impacts to lake habitat in Lake Powell or Lake Mead. Projections of Lake Powell and Lake Mead surface the elevations are discussed in Sections 3.3.4.2 and 3.3.4.4, respectively. These reservoirs will continue to be subjected to varying inflows and fluctuating surface elevations, primarily due to hydrologic conditions present in the ior Inter 17 watershed and increasing water use in the Upper Basin. Historically, reservoir 0 f the conditions have resulted in lake habitat that is favorableo non-native2 pt. to er 29, species and e v. D mb unfavorable to native species. Becausetionprojected declines in reservoir surface a the on Nove the normal operational range elevation in both Lake Powell ajo Lake Mead are within and N d Nav archivein substantial changes to lake habitat. of fluctuations, theyd innot likely to result are , 3.7.3 cite 16864 4SPORT 1 No. FISHERIES This section considers potential effects of the interim surplus criteria alternatives on sport fisheries in Lake Powell, Lake Mead and below Hoover Dam. Potential effects on recreation associated with sport fisheries are discussed in Section 3.9.5. The sport fishery within the Colorado River corridor from Glen Canyon Dam to Separation Canyon is not analyzed in detail in this FEIS because annual release patterns from Glen Canyon Dam are determined in accordance with the 1996 ROD and are monitored through the Glen Canyon Dam Adaptive Management Program. Through this process, the effects of dam operations on downstream resources, including sport fish, are monitored and studied. The results are used to formulate potential recommendations on refinements to dam operations, to ensure that the purposes of the Grand Canyon Protection Act are met. The possibility of changes in river water temperature downstream of Hoover Dam was also investigated. Reclamation conducted an analysis predicting water temperatures downstream of Hoover Dam with a Lake Mead water surface elevation of 1120 feet msl and a steady release of 62,000 cfs (30 percent higher than powerplant capacity). Under COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 292 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 these conditions, the warmest temperature predicted was 58.5°F in late summer. The midsummer discharge temperature was predicted to be 58.5°F (Reclamation, 1991). Under actual conditions with a reservoir elevation of 1120 feet msl, however, maximum discharge would be equal to the powerplant capacity of 49,000 cfs. At this lesser flow, discharges would be cooler than the temperatures predicted in the analysis, since less discharge water would be drawn from the warm upper portion of the reservoir than at higher flows. Therefore, it is assumed that increases of release temperatures corresponding to the median decline of lake levels under baseline conditions and the action alternatives would result in temperatures less than those predicted in the 1981 analysis. Staff from the Willow Beach Federal Fish Hatchery, located about 12 miles downstream of Hoover Dam, reported that over the long term, river water temperatures have typically ranged from 56°F to 58°F, with occasional lows of 54°F. Modeled Hoover Dam discharges are not significantly different from those during periods when water temperatures were measured by hatchery personnel. It is expected that the minor changes in river water temperature described above would not be expected to adversely affect fish populations or the sport fishery in the river below Hoover Dam. The hatchery rears both trout and native fish. For native species, the hatchery warms the r river water with solar panels. The projected increase in river temperatures may be a te io Inarernot17 benefit to the hatchery’s native fish program. River temperatures 0 addressed f the pt. o er 29, 2 further in this section. . De b nv em Natio d on Nov vajo e in Na 4, archiv d reviewed to determine the historic and current status of sport fish Existing literaturee cit was 1686 assemblages in Lake Powell and Lake Mead. Literature reviewed included recent o. 14 Nthe status of sportfishing in both reservoirs, along with a review of publications on 3.7.3.1 METHODOLOGY water quality data including limnological reports and journal articles for information on contaminants found within the lakes and in fish tissue. Potential effects on sport fisheries identified herein are based on the analysis of lake habitat discussed in Section 3.7.2. Potential effects on sport fisheries are based on model output showing general trends of reservoir surface elevations, river flow rates and temperature. No specific threshold elevations or flows are used in the analysis. 3.7.3.2 AFFECTED ENVIRONMENT Currently, Lake Powell and Lake Mead provide habitat for numerous species of introduced (non-native) fish which support outstanding recreational sport fishing opportunities. The fish species present in the GCNRA are listed in Table 3.7-1. A similar species assemblage exists for Lake Mead. The two most common sportfish species found in Lake Powell and Lake Mead are striped bass and largemouth bass. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 293 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.7.3.2.1 CHAPTER 3 Reservoir Sport Fisheries The primary sport fisheries management challenge in the reservoirs is trying to stabilize a striped bass population that reproduces beyond the limits of available forage. As a result of unlimited striped bass reproduction, pelagic (open water) stocks of threadfin shad upon which they prey have been decimated. Decimation of the shad population then results in striped bass starvation. Reduction of striped bass numbers allows the shad population to rebound from adult stocks residing in turbid, thermal refuges where they are less vulnerable to striped bass predation. As shad reenter the pelagic zone in large numbers, they are subsequently eaten by young striped bass who grow rapidly, mature, and once again eliminate shad from the pelagic zone. This widely fluctuating predator-prey cycle occurred during the 1990s and still occurs today. Threadfin shad in Lake Powell exist in the northernmost portion of their range. Lower lethal temperatures for shad are reported as 40°F to 41°F (4.5°C to 5°C). Shad currently survive winters where water temperatures consistently range near the lethal limit by seeking deep strata where the water temperature is warmer and stable. An additional temperature reduction of even 2°F (1.0°C) may remove the thermal refuge and result in loss of shad over winter. The absence of a pelagic forage fish would not eliminate striped bass, which now subsist on plankton for the first year or two ofor but would teri life, eventually result in a permanently stunted striped bass population without 7 he In 201 quality sport of t ept. ber 29, fishing value (NPS, 1996). .D nv vem Natio d on Nomuch the same manner as in Lake jo The sport fishery at Lake Mead has been managed in Nava a the ive inin many,of rchsame management challenges. The introduction Powell and has resulted cited forage 64 of threadfin shad as a4-168 species and striped bass as the main predator has produced 1 similar interactions between the two species. No. 3.7.3.3 ENVIRONMENTAL CONSEQUENCES 3.7.3.3.1 Reservoir Sport Fisheries The sport fishery in Lake Powell and Lake Mead is primarily based on the presence of striped bass. Other sport fish found in the lakes include largemouth bass, catfish and trout. Since the predator-prey relationship between striped bass and threadfin shad can result in large variations of the striped bass population, stabilizing the population of striped bass and maintaining the threadfin shad population is an ongoing challenge to sport fish management in the lakes. Although the occurrence of prey base fluctuations is more directly related to striped bass populations, a thermal refuge for adult threadfin shad is critical. Under baseline conditions and each of the alternatives, the challenge of stabilizing striped bass and threadfin shad populations in the lakes will continue and may include the need to alter the size or catch limit of striped bass or planting of fish from hatchery stock. All of the other sport fish, with the possible exception of trout, are well-adapted to habitats found COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 294 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 in the lakes and are largely unaffected by fluctuating lake levels and water temperatures. Trout populations in the reservoirs are sustained by planting fish from hatchery stock. 3.7.3.3.2 Colorado River Sport Fisheries The primary sport fish in the Colorado River between Glen Canyon Dam and the Lake Mead inflow is rainbow trout. Natural reproduction of rainbow trout in the Grand Canyon is dependent on cool water temperatures, access to tributaries for spawning and continued availability of suitable main stem habitat. These variables are directly related to patterns of flow releases from Lake Powell. Under baseline conditions and each of the alternatives, an increase in the temperature of water released from Glen Canyon Dam could occur if reservoir levels in Lake Powell fall below an elevation of 3590 feet msl. The probability of elevations below 3590 feet msl is limited to the 10 percentile rankings and is not projected to occur until approximately years 2018 to 2028. Water releases from Glen Canyon Dam are controlled by operating criteria contained in the 1996 ROD and are monitored for compliance with the Grand Canyon Protection Act through the Adaptive Management Program. As a result, Colorado River sport fisheries would not be affected by the interim surplus criteria alternatives. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.7-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 295 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.8 SPECIAL-STATUS SPECIES 3.8.1 CHAPTER 3 INTRODUCTION This section identifies potential effects of proposed interim surplus criteria to aquatic and terrestrial species of concern and their habitat, from Lake Powell to the SIB. Potential impacts to special-status species in Mexico are discussed in Section 3.16, Transboundary Impacts. As discussed in Section 1.4, a considerable amount of information pertinent to this analysis is available from various documents prepared by Reclamation and the Service under NEPA and/or the ESA, and is incorporated by reference. Special-status species are species that are listed, or are proposed for listing, as “threatened” or “endangered” under the federal ESA that may be present in the area affected by the proposed action, and also include species of special concern to states or other entities responsible for management of resources within the area of analysis. This section contains a discussion of the life history requirements of each species, followed by an analysis of potential impacts to the species and its habitat. Reclamation is consulting with the Service (and NMFS) to meet itserior t responsibilities under Section 7 of the ESA on the effects of the proposedf action n federally listed he I to 2017 o t species. Reclamation prepared a biological assessment (BA)er 29,evaluates the ept. b which . D them potential effects on listed species which imayv at on occur in ve area from the headwaters of No N Lake Mead to the SIB (Reclamation, 2000). Preliminary evaluation of the effects to vajo hived on Na c listed species whichd in be presentrin the Colorado River corridor from Glen Canyon ite may 6864, a c Dam to the headwater of Lake Mead led to the conclusion that the interim surplus 14-1 o.affect any species. Therefore, this area was not addressed in the BA. criteria would N not Refinements to the model used to predict future operations of Glen Canyon Dam for this EIS indicated there would be a minor change in the frequency with which flows recommended by the 1994 biological opinion concerning operation of Glen Canyon Dam would be triggered. It was determined that this change may affect listed species. The results of this analysis were provided to the Service in a November 29, 2000 memorandum as supplemental information to the BA, which is included in Attachment S. Potential impacts to special-status species occurring in Mexico are discussed separately in Section 3.16, Transboundary Impacts. Specifically, Section 3.16 considers the potential effects on the following species: desert pupfish, vaquita, totoaba, Southwestern willow flycatcher, Yuma clapper rail, yellow-billed cuckoo, California black rail, elf owl, Bell’s vireo, and Clark’s grebe. Although consultation on species occurring in Mexico may not, as a matter of law, be required by the ESA, Reclamation is also supplementing the BA to include information pertinent to federally listed species from this analysis. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 296 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.8.2 CHAPTER 3 METHODOLOGY Information on the affected environment and special-status species that may occur in the analysis area was compiled based on review of the pertinent documents listed in Section 1.4, available published and unpublished literature, and through personal communication with agency resource specialists. Species’ distribution, range and habitat requirements were reviewed. These requirements formed the basis for compiling an initial list of plant, wildlife and fish species to be considered. This analysis first discusses vegetative communities that exist throughout the analysis area, from Lake Powell to the SIB. Potentially affected plant, wildlife and fish species are then determined by considering hydrologic requirements and other habitat elements important to the species, such as nesting or breeding habitat for birds and spawning and rearing areas for fish. Species that are not known to be present in the analysis area, do not depend on terrestrial or aquatic habitat associated with the area under consideration or have a hydrologic connection are addressed briefly and removed from further consideration. The analysis of effects to the remaining potentially affected plant, animal and fish species and their habitat follows the section on the affected environment. ior Inter 17 0 f the pt. o er 29, 2 e D Vegetative communities within the analysis area are discussed, based on if they are mb n v. atiohabitat) Nove the Colorado River (riverside located alongside the reservoirs jo N (lakeside on or along ve Nava arare ithendidentified. The species are divided into habitat). The special-status species ch in , cited 168 wildlife and fish. Tables in this section list the species’ three main categories: plants,64 14common and scientific names and current status, and indicate if critical habitat has been No. 3.8.3 AFFECTED ENVIRONMENT federally designated. Following each table, the occurrence and requirements of the species is provided. Species that would not be affected by the interim surplus criteria are identified and removed from further analysis. 3.8.3.1 LAKE AND RIPARIAN HABITAT A description of lakeside vegetation associated with Lake Powell and GCNRA is provided below, followed by a description of vegetation associated with Lake Mead and LMNRA (which includes Lake Mohave) and Lake Havasu. This section then describes riverside habitat along the Colorado River corridor from Separation Canyon to the Lake Mead delta and below Hoover Dam. Aquatic habitat is discussed in the previous section on Aquatic Resources (Section 3.7). 3.8.3.1.1 Lakeside Habitat Riparian and marsh vegetation around Lake Powell and Lake Mead is extremely restricted because of the desert terrain that extends directly to the water’s edge (Reclamation, 1999d), and the continuously fluctuating lake levels that precludes COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 297 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 establishment of vegetation. Tamarisk or salt cedar (Tamarix ramosissima), a nonnative invasive shrub- to tree-like plant along the Lake Powell shoreline is still becoming established and has not yet formed stable ecosystems. These communities will probably attain some importance as insect and wildlife (particularly bird) habitat in the future, and already provide habitat for fish during high lake levels when the plants are inundated (NPS, 1987). Small intermittent or seasonal streams occur in many of the side canyons of Lake Powell. Fluctuations in lake levels may result in standing water in these side canyons where riparian vegetation has become established. Dominant plants found in these canyons include Fremont cottonwood (Populus fremontii), tamarisk, and cattail (Typha sp.) (NPS, undated b). The vegetation within these side canyons has been altered by the lake itself as a result of periodic inundation in association with fluctuating lake levels. In areas where there are springs and seeps, cattail marshes may be found. The most serious adverse influence on canyon and spring riparian zones associated with intermittent or seasonal streams in the side canyons of Lake Powell is domestic and feral livestock use (NPS, 1987). The GCNRA also has many springs, seeps that are common in alcoves along the canyon walls, and waterpockets located in canyons and uplands. These areas iare recognized for or Inter the 7 their significance as wetland habitats and as unique ecosystems within 01 desert (NPS, f the pt. o er 29, 2 1987). De v. mb tion aalong thenwallsve the canyon support hanging No of The seeps that are common in ajo N valcoves ed o gardens. Hanging gardens are a ,specialized vegetation type and have a unique flora in Na 4 archiv ted 6water associated withci them. The 86 sources that support hanging gardens originate from -1 o. 14 natural springs and seeps within the Navajo sandstone formation and are independent of N Lake Powell. This plant community is found at various elevations around Lake Powell and is typically not affected by reservoir fluctuations. GCNRA hanging gardens are characterized by Eastwood monkeyflower (Mimulus eastwoodiae), alcove columbine (Aquilegia micrantha), Rydberg's thistle (Cirsium rydbergii) and alcove primrose (Primula specuicola). None of these are special-status species at this time, although all four are endemic to the Colorado Plateau. Maidenhair fern (Adiantum sp.) is the most typical species in hanging gardens throughout the Plateau (Spence, 1992). Other species typically associated with hanging gardens include maidenhair fern, golden columbine (Aquilegia chrysantha) and scarlet monkeyflower (Mimulus cardinalis). The highest concentration of habitat associated with Lake Mead in the LMNRA is found in the Lake Mead and Virgin River deltas. Linear riparian woodlands may be present along the shoreline of the Lake Mead delta following high water flows, and associated sediment deposition and exposure. The sediment deposition and the associated growth of riparian vegetation at the Lake Mead delta has occurred for decades (McKernan, 1997). When lake levels decline, vegetation in the Lake Mead and Virgin River deltas begins to establish on clay/silt deposits. The dynamic nature of fluctuating lake levels and deposition of sediment in the Lake Mead delta is expressed COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 298 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 as a change in plant species composition and relative abundance over time. In 1963, tamarisk was the dominant tree species in the Lake Mead delta (McKernan, 1997). In 1996, habitat descriptions for Southwestern willow flycatcher study sites at the Lake Mead delta reported 95 percent of the vegetation as willow or cottonwood with only five percent as tamarisk (McKernan, 1997). An increase in sediment deposition in the deltas followed by lower lake levels allows establishment of native riparian habitat if the lowering of the lake is timed to match native seed dispersal. As such, conditions for establishment of native vegetation at the Lake Mead delta have improved since 1963 allowing cottonwood and willow to become the dominant vegetation. Germination of willows at the Lake Mead delta likely occurred in the spring of 1990 at the approximate water surface elevation of 1185 feet msl (McKernan, 1997 and Reclamation, 1998c). The water surface elevations in 1996 and 1997 were 1192 feet and 1204 feet, respectively (Reclamation, 1998c). These higher lake levels inundated willow habitat in the Lake Mead delta and the Lower Grand Canyon (McKernan, 1997). Until 1998, the Lake Mead delta contained an extensive growth of riparian vegetation principally composed of Goodding willow (Salix gooddingii) (McKernan, 1997). By 1999 the Lake Mead delta willow habitat was completely inundated. To a lesser degree, these same effects may also be seen at the Virgin River delta. A higher delta gradient at or the Virgin River delta results in a shorter period of inundation at nteri(greater than 1192 I high 17 e feet msl) lake levels (Reclamation, 1998c). of th , 20 9 pt. . De ember 2 nv Section VI of the BA (Reclamation, 2000) provides ov atio N additional information on ajo N ived on fluctuations in lake levels and development of riparian habitat at Lake Mead. It notes Nav ch that determiningiexactly how64, aracres of riparian habitat that may be formed due to d in t cate 168 many the proposed interim surplus criteria is declining levels Lake Mead under 14No. problematic. It further states that the majority of the Lake Mead shoreline does not have the soil necessary to regenerate riparian habitat, and that riparian habitat created by declining lake levels would most likely occur in four areas: Lake Mead delta, Virgin River delta, Muddy River delta and the portion of the Lower Grand Canyon influenced by Lake Mead. However, future wet hydrologic cycles, would inundate the newly established riparian habitat. Although higher lake levels may be detrimental to riparian vegetation at the Lake Mead and Virgin River deltas, it may be beneficial to the development of riparian habitat in the lower Grand Canyon downstream of Separation Canyon, and the Virgin and Muddy rivers above Lake Mead (Reclamation, 1998c). Riparian habitat extends from the lake deltas upstream into the lower Grand Canyon and Virgin River Canyon. Development of riparian habitat in these canyons is directly dependent upon fluctuating lake levels and periods of inundation in the canyons. Data collected on riparian vegetation from 1998 Southwestern willow flycatcher surveys (McKernan, 1999) indicate a welldeveloped riparian corridor composed primarily of willow (Salix spp.) and tamarisk that forms extensive and continuous stands in some portions of the lower Grand Canyon. Lower water levels in Lake Mead that expose sediments in the Lake Mead, Virgin River and Muddy River deltas have the potential to benefit establishment of riparian habitat in COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 299 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 these areas. However, lower water levels in Lake Mead do not benefit establishment of riparian and marsh habitat in the lower Grand Canyon. In order for riparian and marsh habitats to become established along the Colorado River in the lower Grand Canyon, higher water levels in Lake Mead are necessary. A few literature sources briefly examine influences of fluctuating lake levels on marsh habitat at the Lake Mead and Virgin River deltas. In 1995, the Lake Mead delta supported hundreds of acres of cattail and bulrush marsh (Reclamation, 1996a). This vegetation type increased after a period of high flows from 1983 to 1986. Deposits containing clay/silt sediments are necessary for the development of emergent marsh vegetation (Stevens and Ayers 1993). Low water velocity sites, such as the Lake Mead and Virgin River deltas, permit clay/silt particles to settle from suspension. These deposits provide a higher quality substrate for seed germination and seedling establishment than underlying sand because of their greater nutrient levels and moisture-holding capacity. With the appropriate water regime (i.e., higher river flows during winter with lower flows during summer), these sites are more likely to support emergent marsh vegetation (Reclamation, 1995b). Marsh vegetation that develops during low lake periods would be lost during periods of high lake levels; however, this habitat is more likely than cottonwood/willow to reestablish as lake levels fluctuate (Reclamation, 1996a). Marsh vegetation that develops during lowtlake levels is ior In er 17 important habitat for many species, particularly breeding f the 20 o birds. , t. Dep mber 29 .2000) provides additional information on nv e The interim surplus criteria BA (Reclamation, Natio d on Novhabitat at downstream reservoirs fluctuations in lake levels and development of riparian ajo ive Nav (Lake Mohave and Lake Havasu).aThe interim surplus criteria are not expected to d in 64, rch ite affect levels of c downstream reservoirs as they would be continue to be regulated to the 4-168 1 meet downstream . No flood control, power generation and water delivery purposes. 3.8.3.1.2 Riverside Habitat The riparian vegetation along the Colorado River is among the most important wildlife habitat in the region. Though not common, springs can be found within the GCNRA in intermittent drainages where they often support wetland plant communities. Between Glen Canyon Dam and Lees Ferry, springs are created by several spontaneous, copious flows from the lower canyon walls (NPS, 1987). The Water Resources Management Plan and Environmental Assessment for the GCNRA speculates that this spring flow originates from Lake Powell bank storage in the Navajo Sandstone (NPS, 1987), and thus, this area could be affected by changes in Lake Powell surface levels. Overall, lower lake levels are not likely to have any impacts on gardens around Lake Powell, but may have some impacts on springs directly associated with Glen Canyon Dam and extending downriver approximately two to three miles. In the lower canyon, arrowweed (Pluchea sericea) and horsetail are common. Below Havasu Creek, bermuda grass becomes the dominant ground cover at many sites (Reclamation, 1996a). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 300 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Mesquite (Prosopis glandulosa) historically occurred on the broad alluvial floodplains of the Colorado River on secondary and higher terraces above the main channel (LCRMSCP, undated). It still is a dominant species above the scour zone through the Grand Canyon (Ohmart et al., 1988; Turner and Karpiscak, 1980); however, tamarisk is replacing mesquite in many areas along the Colorado River. Catclaw acacia occurs along watercourses and other areas where a summer water supply may be present (Barbour and Major, 1995; Brown, 1994; Holland, 1986; Sawyer and Keeler-Wolf, 1995). This species occurs in both upland and riparian vegetation associations (Reclamation, 1996a). Catclaw acacia in the Grand Canyon can occur with Apache plume (Fallugia paradoxa), a typical constituent in the acacia-mesquite habitat. It may also be found with desert broom (Baccharis spp), which is an obligate riparian species that occurs in the cottonwood-willow habitat type (Turner and Karpiscak, 1980). Two types of marsh plant associations have been identified along the Colorado River (Stevens and Ayers, 1991). Marshes were historically found along oxbow lakes and in backwater areas along the Colorado River. Cattails, bulrushes, common reed and some less common emergent plants occur in marsh areas that develop on sediment deposits containing about half clay/silt and half sand (Reclamation, 1995). erior nt 7 the I f surplus 9, 201may affect In the lower Grand Canyon above Lake Mead, theept. o interim 2 criteria D er backwater marshes due to the changes inon v. levels.vemb changes in water levels i water No These at on could affect temperature and vajo water quality considerations, as well as the other N ived of the BA (Reclamation, 2000) discusses Na establishment of marshn i vegetation. rSection V a ch citedmarsh,864, historic and existing -16 backwater and aquatic habitat on the lower Colorado River 14 below Hoover, Davis and Parker dams. No. 3.8.3.2 SPECIAL-STATUS PLANT SPECIES The list of special-status plants in Table 3.8-1 below is based on documented or potential occurrence within vegetation communities of the Glen Canyon National Recreation Area (GCNRA), Lake Mead National Recreation Area (LMNRA) and the Colorado River corridor in the lower Grand Canyon. No special-status plant species were identified for analysis below Hoover Dam. Nineteen plant species were removed from detailed consideration, as discussed in the next section. Four species could be affected by interim surplus criteria alternatives and are considered further. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 301 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.8-1 Special-Status Plant Species Potentially Occurring Within the Area of Analysis Common Name Scientific Name Alcove bog orchid Alcove daisy Alcove deathcamas Barrel cactus Habenaria zothecina Erigeron zothecinus Zigadenus vaginatus Ferrocactus acanthodes var. lecontei Brady’s footcactus Canyonlands sedge Pediocactus bradyi Carex scirpoidea var. curatorum Astragalus geyeri var. triquetrus Camissonia specuicola ssp. Hesperia Geyer’s milkvetch 1 Grand Canyon evening1 primrose Hole–in-the-Rock prairie clover Jones cycladenia Dalea flavescens Status Federal Species of Concern Federal Species of Concern Federal Species of Concern Northern Nevada Native Plant Society (NNNPS) Watch List species and Listed as Sensitive by the Service (Intermountain Region) Federally Listed Endangered Federal Species of Concern Federal Species of Concern; Nevada Critically Endangered Federal Species of Concern Federal Species of Concern Ute ladies’ tresses Virgin River thistle Cycladenia humilis var. jonesii Erigeron kachinensis Arctomecon californica Carex specuicola Rubus neomexicana Perityle specuicula Penstemon bicolor ssp. Roseus Imperata brevifolia Cladium californicum Eriogonum viscidulum Psorothamnus thompsoniae var. whittingii Spiranthes diluvialis Cirsium virgenense Western hophornbeam Ostrya knowltonii Federally Listed Threatened ior t Concern Inofer 17 Kachina daisy Federal Species f the 9, 20 1 Nevada Las Vegas bear poppy pt. o Listed Critical Endangered De Federallyber 2Threatened Navajo sedge n v. ovem Listed Natio d on NFederal Species of Concern New Mexico raspberry vajo e Rock Daisy Federal Species of Concern in Na 4, archiv d te 86 Rosy bicolored ci Federal Species of Concern 16 beardtongue . 14No Satintail grass Federal Species of Concern Sawgrass 1 Sticky buckwheat Thompson’s indigo-bush 1 Federal Species of Concern Federal Species of Concern Federal Species of Concern Federally Listed Threatened Federally Listed Species of Concern; Arizona Salvage-restricted, Protected Native Plant Federal Species of Concern Species with the potential to be affected by the interim surplus criteria that are considered further. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 302 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.8.3.2.1 CHAPTER 3 Plant Species Removed from Further Consideration This section discusses the reasons for eliminating certain special-status plant species from detailed consideration. Special-status plant species that occur in hanging gardens at GCNRA include alcove bog orchid, alcove daisy, alcove deathcamas, canyonlands sedge, Kachina daisy, Navajo sedge, New Mexico raspberry, sawgrass, western hophornbeam and Virgin River thistle. The water source for these species comes from seepage from the Navajo sandstone that would not be affected by hydrologic changes associated with interim surplus criteria. Barrel cactus, Brady’s footcactus, rosy bicolored beardtongue, Jones cycladenia and Thompson’s indigo-bush are desert species. This habitat type and associated plant species would not be affected by interim surplus criteria. Hole-in-the-Rock prairie clover occurs in the Hall’s Creek and Escalante drainages in the GCNRA, which would not be affected by hydrologic changes associated with the interim surplus criteria. ior ter Rock daisy occurs at Cedar Mesa in GCNRA, growing in sandstone along 7 margins the he In be0affected by of an ephemeral stream channel at the canyon bottomt. of would29, 2 1 that t not Dep mber interim surplus criteria. n v. e Natio d on Nov ajo Wilson’s Creek in the GCNRA, an area that would Satintail grass occurs within lower rchive Nav d in surplus a not be affected cite by interim6864, criteria. -1 o. 14 N Sawgrass has been found in the riparian zone of Alcove Canyon in Grand Canyon National Park, and in the riparian zone of Garden Canyon on the cliffs above Lake Powell. These riparian zones would not be affected by interim surplus criteria. Ute ladies’ tresses occur in moist to wet meadows along perennial streams at elevations between 4,300 and 7,000 feet msl. These occurrences are above those elevations that occur within the area under consideration. As such, this species would not be affected by interim surplus criteria. Virgin River thistle occurs on sandy or gravelly alkaline slopes and washes and around saline seeps, alkaline springs or stream terraces. It occurs between elevations of 1968 and 6562 feet msl, and is associated with Mojave mixed scrub habitat. This habitat type would not be affected by interim surplus criteria. As such, this species would not be affected by interim surplus criteria. 3.8.3.2.2 Plant Species Considered Further Geyer’s Milkvetch - Geyer’s milkvetch is known to occur along the shoreline of Lake Mead and is associated with stabilized sand dunes and sandy soils. Population trends COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 303 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 have not been well documented for Geyer’s milkvetch. Germination may be tied to rainfall, and poor seed production and insect infestations may contribute to the limited distribution and/or small population sizes observed for this variety (Mozingo and Williams, 1980). Some populations have been directly affected by rising water levels at Lake Mead (i.e., Middle Point). Additional causes of decline for this taxon may include shoreline recreation, trampling and grazing by burros and livestock, off-road vehicle use, and utility corridors (Niles et al., 1995). Threats to Geyer’s milkvetch in the study area have not been well defined. This variety may be potentially threatened by: 1) loss of habitat from inundation and rising water levels at Lake Mead; 2) invasion of shoreline (beach) habitat by other plant species (i.e., tamarisk and arrowweed); and possibly 3) trampling and grazing by burros. Geyer’s milkvetch occurs further back from the shoreline and may be less affected by these factors (E. Powell, 2000). Shoreline recreation does not currently appear to be a major threat to this species because the beaches where it occurs do not receive heavy recreational use. In addition, the species typically flowers and sets seed prior to the beginning of heavy use periods at Lake Mead (Niles et al., 1995; E. Powell, 2000). However, rising lake levels may potentially affect this species directly by inundation of plants or indirectly through inundation of suitable habitat. ior Inter is17clustered Grand Canyon Evening Primrose - Grand Canyon evening e of th primrose 0 a pt.yelloweor 29, 2at anthesis herbaceous perennial plant with small flowers .thate D are b r white ion v aging. The (flowering), but may turn to pink or lavender withNovem Grand Canyon evening Nat primrose occurs on beachesavajoor near ed on stem Colorado River in the vicinity along iv the main N of Separation Canyon iand downstream of Diamond Creek where available beach habitat d n 64, arch cite is exposed (Brian, 2000 168Phillips, 2000). This species is likely adversely affected . 14- and when beaches No disturbed through erosion or deposition of sediments during flood are events. Some degree of flooding occurs seasonally as the result of increases in sidechannel inflows during rainfall events. Additional flood flows result from periodic BHBF releases from Glen Canyon Dam. The degree to which flooding adversely affects this subspecies and which water levels are detrimental to the plants and its habitat is unknown. However, the amount of beach habitat in the Grand Canyon has decreased under post-dam conditions, and the remaining habitat is often invaded by riparian vegetation (Schmidt et al., 1998). Because this subspecies is found on good camping beaches, particularly in the lower portion of the Grand Canyon, it may also be adversely affected by disturbance associated with recreational beach use; however, this potential effect is not related to the interim surplus criteria. Las Vegas Bear Poppy - Las Vegas bear poppy is a short-lived perennial species, occurring along the lower levels of the Lake Mead shoreline (E. Powell, 2000). This plant occurs on gypsum soils below the high water line of Lake Mead (1225 feet msl) on sloping flats. Little is known about the life cycle of the Las Vegas bear poppy, and populations vary in a “boom or bust” pattern (E. Powell, 2000). This species would benefit from lower water levels at Lake Mead, and could be adversely affected by COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 304 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 increases in water levels although timing of water fluctuations and associated effects to this species are unknown. Sticky Buckwheat - Sticky buckwheat is found primarily along the Overton Arm of Lake Mead (Reveal and Ertter 1980, Niles et al., 1995). Smaller, potentially significant populations occur in the vicinity of Overton Beach, along the Virgin River Valley, and along the Muddy River. Major threats to sticky buckwheat at Lake Mead include: 1) loss of habitat from inundation and rising water levels at Lake Mead; 2) invasion of shoreline (beach) habitat by other plant species (i.e., tamarisk and arrowweed); and possibly three) trampling and grazing by burros. Shoreline recreation does not currently appear to be a major threat to this species because the beaches where it occurs do not receive heavy recreational use. In addition, the species typically flowers and sets seed prior to the beginning of heavy use periods at Lake Mead (Niles et al., 1995). This species would benefit from lower water levels at Lake Mead, and could be adversely affected by increases in water levels. 3.8.3.3 SPECIAL-STATUS WILDLIFE SPECIES Special-status wildlife species with the potential to occur within the area under consideration in the United States are listed in Table 3.8-2. Two invertebrate, two ior Inter and two amphibian, and one reptile species are of concern. Eleven bird species 017 f the pt. o on er 29, 2 mammals are of concern. A number “1” after .the e D species b the table indicates the ion v Nosurplus species has the potential to be affected by the interim vem criteria alternatives, and is Nat d on therefore assessed in more detail.o vaj a ive in N rch ited 6864, a c -1 o. 14 N COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 305 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.8-2 Special-Status Wildlife Species Potentially Occurring Within the Area of Analysis Common Name Scientific Name Status Invertebrates MacNeill’s sootywing skipper Hesperopsis gracielae Federal Species of Concern Kanab ambersnail Oxyloma haydeni kanabensis Federally Listed Endangered; Arizona Wildlife of Special Concern Amphibians Northern leopard frog Rana pipiens Arizona Candidate for Listing Relict leopard frog Rana onca Nevada State Protected; Arizona Wildlife of Special Concern Kinosternon sonoriense sonoriense California Species of Special Concern Falco peregrinus anatum California Endangered; Nevada State Protected and Endangered California Endangered Reptiles Sonoran mud turtle Birds American peregrine falcon Arizona Bell’s vireo 1 Vireo bellii arizonae ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove 1 Laterallus jamaicensis California black rail jo N coturniculus Nava archived in 1 Aechmophorus clarkii Clark's grebe cited 16864, 4.1 1 Accipiter cooperii California Species of Special Cooper's hawk No Bald eagle 1 Haliaeetus leucocephalus Federally Listed Threatened; California Endangered; Nevada State Protected and Endangered Federal Species of Concern; California Threatened Arizona Wildlife of Special Concern Micrathene whitneyi Concern California Endangered Gilded flicker Colaptes chrysoides California Endangered Southwestern willow 1 flycatcher Empidonax traillii extimus Federally Listed Endangered (critical habitat designated); California Endangered; Nevada State Protected Federally Listed Endangered; California Threatened Federally Proposed Endangered; California Endangered; Nevada State Protected Elf owl 1 1 1 Rallus longirositris yumaniensis Yuma clapper rail Western yellow-billed cuckoo 1 Coccyzus americanus Mammals Colorado River cotton rat Sigmodon arizonae plenus Occult little brown bat Myotis lucifugus occultus 1 Federal Species of Concern; California Species of Special Concern Federal Species of Concern; California Species of Special Concern Species with the potential to be affected by the interim surplus criteria that are considered further in this analysis. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 306 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.8.3.3.1 CHAPTER 3 Wildlife Species Removed from Further Consideration The Kanab ambersnail occurs in semi-aquatic habitat associated with springs and seeps. In the Grand Canyon, Kanab amber snail were originally known to occur only at Vasey’s Paradise, a large perennial spring. As part of an effort to recover the species, Kanab amber snails were translocated from Vasey’s Paradise to three other locations. One of the criteria used to select these sites was that it be above the level of any potential future flood flows past Glen Canyon dam. These populations would not be affected by the adoption of interim surplus criteria. Reclamation has consulted with the Service on the effects to the Vasey’s Paradise population from the operations of Glen Canyon Dam. The resulting biological opinion (USFWS, 1996) continues to be implemented and will not be affected by the proposed action. There will be no effect from the adoption of interim surplus criteria. The northern leopard frog is known to occur in association with a spring at one site below Glen Canyon Dam. The population was monitored before and after the 1996 BHBF and found to persist under these flows. This species receives consideration under the Glen Canyon Dam AMP (see Section 3.2.2). The minor changes to operations of Glen Canyon due to adoption of the interim surplus criteria are not expected to affect the northern leopard frog. erior Int 0 f the several17 o Historically, the relict leopard frog (Rana onca) was known from 9, 2 locations ept. ber 2 D along the Virgin river, and from the Overtonv. of ovem to north n atiothe arm N Lake MeadMeadow of St. George, N n River and o Utah. This species was also known from ed Muddy Valley Wash vajo v in Nevada, northwest of the Overtonchi This species was thought to be extinct, but in Na 4, ar Arm. cited 1 of 6 was rediscovered at three 6851 potential habitat sites surveyed in 1991. Surveys 4conducted for No. 1 relict leopard frog included potential habitat within the historical range of the species (Bradford and Jennings 1997). There are confirmed sightings of this species at springs about two miles (3.2 km) west of Stewarts Point on the Overton Arm of Lake Mead. A fourth population of leopard frog on the Virgin River near Littlefield, Arizona is within the range of the lowland leopard frog (R. yavapaiensis) and is still awaiting additional studies to confirm its taxonomic status. Other unconfirmed sightings are on the Virgin River near Littlefield, Arizona and about four km (2.5 miles) downstream from Hoover Dam. In general, leopard frogs inhabit springs, marshes, and shallow ponds, where a yearround water supply is available. Emergent or submergent vegetation such as bulrushes or cattails provides the necessary cover and substrate for cover and oviposition (Jennings et al., 1994). Suitable aquatic habitat, as well as, adjacent moist upland or wetland soils is required by the relict leopard frog. In addition, dense herbaceous cover and a canopy of cottonwoods or willows characterize habitat for this species. The relict leopard frog populations located near the Overton Arm of Lake Mead are associated exclusively with geothermally influenced and perennial desert spring communities. Because the known populations are currently confined within a five-mile COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 307 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 (8km) area (Bradford and Jennings 1997), they are susceptible to extirpation from localized impacts. Threats to this species include habitat destruction, lowering of the water table, and predation by introduced bullfrogs (AGFD, 1996; AGFD 1998). The known occurrences of relict leopard frogs are in association with springs that will not be affected by the interim surplus criteria alternatives being considered. If additional emergent marsh vegetation develops at the Lake Mead and Virgin River deltas as the result of lower lake levels, it may provide potential habitat for the relict leopard frog. However, predation by introduced fishes and bullfrogs may preclude occurrence of the leopard frogs in these areas. Reclamation concludes that the interim surplus criteria do not have the potential to affect the relict leopard frog. MacNeill’s sootywing skipper is a butterfly found along the Colorado River from southern Utah and Nevada to Arizona and southeastern California (Reclamation, 1996a). Confirmed records of this species are reported for the Arizona counties of Mohave, La Paz, Yuma, Yavapai, Maricopa and Pinal. The MacNeill’s sootywing skipper is also present in San Bernardino, Riverside and Imperial counties in California. This species also occurs along the Muddy River above Lake Mead (Austin & Austin, 1980). erior Int The larval host plant for MacNeill’s sootywing skipper is quailbrush (Atriplex f the and2017 dense lentiformis). Quailbrush is the largest salt bush found .in Arizona 9, forms pt o . DeRivermber 2 and Emmel, 1973). thickets along the drainage system of theon v Colorado e (Emmel Nati located in ov n N alkaline soil areas with adequate Quailbrush is associated withvajo a floodplains ed o water resources (KearneyN Peebles, 1951). Specific surveys for this species and in and 4, archiv cited not 86 larval host plants have -16been conducted in the lower Grand Canyon; however, the 14 documented occurrence of MacNeill’s sootywing skipper along the Muddy River above No. Lake Mead indicates there is a likelihood of occurrence in the lower Grand Canyon. Suitable habitat for this species likely requires stands of more than one host plant (W. Wiesenborn, 1999). Although this species occurs in the area of analysis, the host plant occurs on alluvial floodplains and has little potential to be affected by the alternatives considered for the interim surplus criteria. Lake Powell and Lake Mead provide breeding and wintering habitat for American peregrine falcons. The peregrine falcon breeds at sites on Lake Mead, and the upper portion of Lake Mohave. Wintering and breeding peregrines are also found around Lake Powell, with an estimated 50 breeding areas (Interior, 1995), and 19 wintering territories (Hetzler, 1992a). Based on historical data, the average height above water of peregrine nests at GCNRA is approximately 460 feet (141 meters), with average cliff heights of 630 feet (193 meters) (Hetzler 1992a, Hetzler 1992b). These data include nest sites in Glen Canyon immediately below the Glen Canyon Dam as well as sites on Lake Powell. Glen Canyon Dam operations have resulted in increased riparian vegetation which supports a larger population of passerines and increased the food base for peregrine falcons. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 308 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Existing and potential American peregrine falcon breeding habitat also occurs in the Grand Canyon between Glen Canyon Dam and Lake Mead and in Black Canyon, (south of Lake Mead). Because their nesting sites are well above the water and their food base has increased, peregrine falcons would not be affected by hydrologic changes associated with the interim surplus criteria and have been eliminated from further analysis. The Sonoran mud turtle, Colorado River cotton rat, and occult little brown bat were removed from further consideration because there are no known occurrences in the analysis area. 3.8.3.3.2 Special-Status Wildlife Species Considered Further Arizona Bell’s Vireo - The Arizona Bell’s vireo (Vireo bellii arizonae) is distributed throughout the river systems of the Southwest desert and have been documented in the Virgin and Muddy rivers, and the lower Colorado River. Since 1900, populations of this subspecies of Bell’s vireo have declined along the lower reaches of the Colorado River, where it is now a rare, to locally uncommon, summer resident from Needles south to Blythe (Brown et al., 1983; Zeiner et al., 1990a; Rosenberg et al., 1991). Since the completion of Glen Canyon Dam in 1963, the Bell’s vireo has expanded its range eastward into Grand Canyon National Park (Brown et al., 1983). Anrextensive riparian ior Inte 17 scrub, that has developed along the Colorado River in thefGrand Canyon largely the 0 pt. o er 29 2 composed of tamarisk and willow, supports a significant population,of Bell’s vireo e b v. D (Brown et al., 1983). The Grand Canyon population ofem vireo is regionally ation on Nov Bell’s oN important due to the substantial decline ofed subspecies at lower elevations. The this avaj NArizona rchiv vireo may potentially be affected by the inby 4, a Bell’s riparian habitat utilized ited 6 interim surplusc criteria.-168 4 No. 1 Bald Eagle - The bald eagle historically ranged throughout North America except extreme northern Alaska and Canada and central and southern Mexico. In 1978, in response to lowering population and reproductive success, the Service listed the bald eagle throughout the lower 48 states as endangered except in Michigan, Minnesota, Wisconsin, Washington and Oregon, where it was designated as threatened (43 FR 6233, February 14, 1978). In 1982, a recovery plan was developed specifically for the southwestern bald eagle; the geographic boundary includes southeast California within 10 miles of the Colorado River or its reservoirs. The bald eagle population has clearly increased in number and expanded its range since it was listed. This improvement is a direct result of the banning of DDT and other persistent organochlorines, habitat protection, and from other recovery efforts (60 FR 36001, July 12, 1995). On August 11, 1995, FWS reclassified the bald eagle from endangered to threatened in the lower 48 states. (60 FR 133, pg. 3600, August 12, 1995). Reclamation’s 1996 BA concluded that its Lower Colorado river operations and maintenance activities are not likely to adversely affect the food resources, foraging opportunities, or the nesting habitat of the bald eagle. Based on data from bald eagle winter counts conducted by the AGFD since 1992, eagles are not considered rare within COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-14 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 309 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 the project area. Wintering birds are expected to continue using the river and most likely will congregate where food resources are plentiful and excessive disturbance from recreation can be avoided. The 1996 BA also cites studies by Hunt et al., (1992) that conclude reservoirs and dams did not appear to have a negative effect on bald eagle reproduction. River operations and maintenance may affect establishment of newly regenerated cottonwood/willow stands that could provide future nesting and perching substrate for eagles. However, as documented in Hunt et al. (1992), bald eagles can successfully nest on other substrates (cliffs, pinnacles). Reclamation’s ongoing native riparian plant restoration program has the potential to increase available tree nesting and perching habitat along the river. No evidence exists to suggest that the food resources available in the reservoirs and river are limiting nesting. Because of the minor changes to the operation of Glen Canyon Dam and the minor hydrologic changes in the reservoirs and along the river, Reclamation determined that adoption of the interim surplus criteria would not adversely affect the bald eagle. California Black Rail - California black rail (Laterallus jamaicensis coturniculus) have recently been documented in the Virgin River Canyon, including the corridor above Lake Mead (McKernan, 1999). In general, Flores and Eddleman (1995) found that black rails utilize marsh habitats with high stem densities and overhead coverage that were drier and closer to upland vegetation than randomly selected teriorMarsh edges n sites. he ICalifornia7bulrush and with water less than 2.5 centimeters (1 inch) deep dominated by , 201 of t ept. ber 29 three-square bulrush (Scirpus californicus and.S. americanus, respectively) are utilized v D vem most frequently. Areas dominated byation are also used regularly, but only in a small cattail No N v and hived on proportion to their availability ajo generally within 50 meters (164 feet) of upland c in Na vegetation wheretwater depth is , arcentimeters (1.2 inch). The occurrence and i ed 6864 3.0 c potential impacts to14-1 along the river corridor in Mexico are also discussed in species No. Section 3.16. Clark’s Grebe − Clark's grebes (Aechmophorus clarkii) are typically less abundant than the western grebe at most locations throughout their range (Ratti, 1981; Zeiner et al., 1990a). A 1977 winter survey found Clark's grebes comprised less than 12 percent of Aechmophorus grebe sightings at locations within California and areas near Lake Mead (Ratti, 1981). At Lake Mead, a total of 321 western grebes were detected during the winter, while only three Clark's grebes were observed. At Lake Havasu, western grebes are also more abundant than Clark’s grebes in the winter. However, Clark’s grebes are more numerous in the breeding season, making up approximately 65 percent of the breeding colony (Rosenberg et al., 1991). Although the cattail and bulrush marsh habitat found at the Lake Mead delta exhibits characteristics preferred by Clark’s grebe, it is not known whether this species currently occurs at the delta. The marsh habitat at the Lake Mead and Virgin River deltas, and in the Colorado and Virgin rivers above Lake Mead may potentially be utilized by Clark’s grebe and may be affected by the interim surplus criteria. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-15 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 310 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Cooper’s Hawk − Cooper’s hawks (Accipiter cooperii) are associated with deciduous mixed forests and riparian woodlands and nests mainly in oak woodlands, but also use willow or eucalyptus woodlands. The Cooper’s hawk nests near streams and prefers mature trees with a well-developed understory for nesting sites (Ziener et al., 1990a). Breeding activity has been documented in the lower Grand Canyon, below Separation Canyon, and in the lower Virgin River above Lake Mead (McKernan, 1999). The riparian habitat currently utilized by Cooper’s hawk in the lower Grand Canyon and lower Virgin River may be affected by the interim surplus criteria. Elf Owl − The elf owl (Micrathene whitneyi) is a secondary cavity nester and, as a result, the population status of the elf owl is directly dependent on available nesting holes in trees made by woodpeckers. As an insectivore, the elf owl is also dependent on sufficient numbers of insects during the breeding season (Johnsgard, 1988). In California, at the extreme northwest edge of its range, the elf owl is likely declining in the few desert riparian habitats that it occupies (Johnsgard, 1988). There may also be a general decline in Arizona, although it may be increasing its range in north-central Arizona and western New Mexico. The species’ overall status in the Southwest has not been determined. The elf owl was never a common or widespread species along the lower Colorado River. Surveys of riparian habitats in the lower Colorado River Valley in 1987 reported between 17 and 24 owls at ten different sites (CDFG,or te i I 25 r 1991). heton breeding pairs Population estimates in California for the early 1990s weret17 017 f pt. oin the rGrand2 29, Canyon may (CDFG, 1991; Rosenberg et al., 1991). Riparian habitat be v. De vem ion owl; however, based on the available provide suitable breeding habitat for the elf No Nat vajo hived on information, it is unknown whether elf owls occur. The riparian habitat along the c n Na Colorado RivercaboveiLake Meadar be utilized by elf owl and has the potential to be ited 6864, may affected by the interim -1 . 14 surplus criteria. No Gilded Flicker − The gilded flicker (Colaptes chrysoides) occurs along the lower Colorado River Valley in southern Arizona and southeastern California (Rosenberg et al., 1991). In California, the gilded flicker is an uncommon resident along the Colorado River north of Blythe (Garrett and Dunn, 1981, CDFG, 1991). During the breeding season, the gilded flicker is found in saguaro habitats, mature cottonwood-willow riparian forests, and occasionally mesquite habitats with tall snags (CDFG, 1991; Rosenberg et al., 1991). This species was historically widespread in riparian habitat all along the Colorado River Valley. Based on available information, it is not known whether this species occurs in the lower Grand Canyon, although suitable habitat is present in both the riparian and mesquite habitats. Southwestern Willow Flycatcher − The Southwestern willow flycatcher (Empidonax traillii extimus) is a riparian obligate, neotropical migratory insectivore that breeds along rivers, streams, and other wetlands where dense willow, cottonwood, tamarisk, or other similarly structured riparian vegetation occurs (Service, 1995a; McKernan 1999; AGFD, 1997e). Populations of breeding Southwestern willow flycatchers have been recorded at the upper Lake Mead delta, the Virgin River delta, Mormon Mesa North, and the Lower Grand Canyon (AGFD, 1997e; Sogge et al., 1997). However, due to COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-16 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 311 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 high lake levels, as discussed previously, the Lake Mead and Virgin River delta willow flycatcher habitat has been inundated. This change in reservoir elevation has permitted suitable willow riparian habitat to develop in the Colorado River corridor from Lake Mead up to approximately Separation Canyon (McKernan, 1999). The occurrence of this species and habitat below Lake Mead to the SIB is discussed in the BA for this proposed action (Reclamation, 2000). The Grand Canyon population of Southwestern willow flycatcher is important from a scientific and management perspective because it is one of the longest continuously monitored populations in the southwest (Sogge et al., 1997). In support of this view, the USFWS designated river mile 39 downstream to river mile 71.5 as critical habitat for this species (USFWS, 1997a, 1997c). This habitat occurs in the upper Grand Canyon and will not be affected by the interim surplus criteria. High lake levels (above 1192 feet) appear to be detrimental to Southwestern willow flycatcher nesting habitat at Lake Mead delta due to potential loss of suitable nest trees (Reclamation, March 1998). Lake levels below 1192 feet during the willow flycatcher breeding season (April through August) appear to allow for increased willow habitat establishment which would be beneficial to the species. From January 1978 until June 1990, Lake Mead elevations were above 1182 feet on a continuous erior In June 1990, basis. Int below that Lake Mead elevation declined to approximately 1182 feet and stayed 017 f the p . o er 29, 2 elevation until the end of 1992 (Reclamation, 2000). tIf saturated soils are present in . De b areas occupied by willow flycatcher, declines in lake levels during June have little to no ion v Novem at jo N v Mead’s effect on nesting. In contrast, when Lake ed on elevation is high enough to inundate Nava duringiJune and July (Reclamation, 2000), willow in the delta, which typically occurs, arch 64 cited be affected because their territories and possibly nest sites would flycatchers would not4-168 o. 1 be established.NBecause suitable habitat utilized by Southwestern willow flycatcher may be affected by changes in Lake Mead water levels that would result from implementation of the interim surplus criteria, the species is considered in the environmental consequences section below. The interim surplus criteria are not expected to result in hydrologic changes below Hoover, Davis and Parker dams that would adversely affect the flycatcher. Yuma Clapper Rail − The Yuma clapper rail (Rallus longirostris yumanensis), one of seven North American subspecies of clapper rails, occurs primarily in the lower Colorado River Valley in California, Arizona and Mexico. It is a fairly common summer resident from Topock Gorge south to Yuma in the United States, and at the Colorado River delta in Mexico. In the area under consideration, the Yuma clapper rail is associated with freshwater marshes with the highest densities of the subspecies occurring in mature stands of cattails and bulrush (Reclamation, August 1999). In recent years, individual clapper rails have been heard at Laughlin Bay and Las Vegas Wash in southern Nevada (NDOW, 1998), and individuals have been documented at the Virgin and Muddy rivers including the Virgin River floodplain between Littlefield, AZ and the Virgin River Delta, NV (McKernan, 1999), and at sites within the lower Grand Canyon (McKernan, 1999). The occurrence of the Yuma Clapper below Lake Mead to COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-17 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 312 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 the SIB is discussed the BA for this proposed action (Reclamation, 2000). The marsh habitat utilized by Yuma clapper rail has the potential to be affected by the interim surplus criteria. Western Yellow-billed Cuckoo − Historically, the western form of the yellow-billed cuckoo (Coccyzus americanus) was a fairly common breeding species throughout the river bottoms of the western United States and southern British Columbia (Gaines and Laymon, 1984). Due to the loss of riparian woodland habitat, the cuckoo has become an uncommon to rare summer resident in scattered locations throughout its former range. Western yellow-billed cuckoo have been documented in riparian habitat in the lower Grand Canyon and Virgin River above Lake Mead (McKernan, 1999) (Reclamation, 2000) as well as in habitat along the river corridor below Lake Mead and has the potential to be affected by the interim surplus criteria. 3.8.3.4 SPECIAL-STATUS FISH SPECIES Described below are special-status fish species present within the area under consideration. Table 3.8-3 lists special-status fish species including common name, scientific name and status. Currently, the Service is supplementing existing recovery plans for the four endangered fish species included in this analysis. erior t 7 he In . of t listed9, 201 Critical habitat has been designated for each of the federally er 2 fish species (Federal pt De Register: March 21, 1994), and portionsionthis habitat existb of v. em within the area of potential Nat d on Nov effect (Reclamation, 2000). vajo ive Na d in 64, archTable 3.8-3 cite 68 Special-Status -1 Species Potentially Occurring Within the Area of Analysis . 14 Fish No Common Name Scientific Name Bonytail Gila elegans Colorado pikeminnow Ptychocheilus lucius Flannelmouth sucker Catostomus latipinnis Humpback chub Razorback sucker Gila cypha Xyrauchen texanus Status Federally Listed Endangered (critical habitat designated); California Endangered; Nevada State Protected Federally Listed Endangered (critical habitat designated); California Endangered Federal Species of Concern; Arizona Wildlife Species of Concern; Bureau of Land Management Nevada Special Status Species Federally Listed Endangered (critical habitat designated) Federally Listed Endangered (critical habitat designated) Bonytail − Adult bonytail (Gila elegans) were once found throughout the big rivers and major tributaries of the Colorado River basin. Younger fish utilize the smaller streams and quiet areas. Bonytail prefer substrate which consists of clay, soft mud, or mud and sand, or occasionally rocks, gravel or rubble with little or no vegetation (Sigler COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-18 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 313 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 and Miller, 1963; Wydoski, 1995). Adults range between eight and 17 inches in length and weigh just over one pound. The species can live for over 40 years. Spawning occurs in late spring to early summer usually over gravel bars with no nest being constructed. Gravid females can carryover 10,000 eggs each. Bonytail are carnivorous, feeding on insects, crustaceans, small fish, and snails; however, filamentous algae are often consumed (NPS, 1998). The bonytail is now the rarest native fish within the Colorado River Basin (NPS, 1998). The decline in the number of bonytail are thought to be a result of changes in historical stream flow and water temperatures, blockage of migratory routes by dams and introduction of non-native fish species. At Lake Powell, present numbers are accounted for by fish older than 40 years of age; no recruitment has been demonstrated in recent years (NPS, 1998). Bonytail are believed to be extirpated in the Colorado River from Glen Canyon Dam to Hoover Dam (McCall, 1979 and Reclamation, 1996a). Small populations may still exist in the Upper Basin, but there is much confusion in fish identification due to the similarity in physical appearance with roundtail chubs (Reclamation, 1996a). Five suspected bonytail were captured in Cataract Canyon between 1985 and 1988, with one caught in Lake Powell near Wahweap Marina (Maddux et al., 1993erior and Reclamation, Int 1995). 017 f the 9, 2 pt. o . De efromeHoover Dam to Davis b r2 Critical habitat for bonytail includes theion v t Colorado River m Naincludes n Nov Dam, including Lake Mohave.aIt also ed o the Colorado River from the northern v jo boundary of Havasu National Wildlife Refuge to Parker Dam, including Lake Havasu. in Na 4, archiv cited 1686 The largest remaining population of bonytail in the entire Colorado River Basin resides 4in Lake Mohave. . 1 were at least nine augmentation stockings of bonytail into Lake No There Mohave between 1981 and 1991 (Reclamation, 1996a). Efforts are being undertaken to repatriate bonytail back to Lake Havasu from lakeside coves using young obtained from Dexter National Fish Hatchery (Reclamation, 1996a). The primary limiting factor for bonytail appears to be non-native fish predation of the early life stages (egg to subadult) (Reclamation, 1996a). Colorado pikeminnow − The Colorado pikeminnow (Ptychocheilus lucius) is the largest member of the minnow family within North America and is endemic to the Colorado River system. It was, historically, the top predator fish in the Colorado River, but native populations are now restricted to the upper Colorado River Basin (Reclamation, 1996a). A portion of their current distribution includes the Colorado River from Palisades, Colorado, downstream to Lake Powell (NPS, 1998). Colorado pikeminnow have been captured in Lake Powell as recently as 1999 (Reclamation, file data). Designated critical habitat within the area of effect for the analysis is limited to the normal pool elevation of Lake Powell. Colorado pikeminnow are now considered extirpated from the entire Lower Basin; where they were once extremely abundant. The last known wild adults from the lower Colorado River were captured in the 1960s, and the last known specimens from the Gila River basin were collected in 1958 (Minckley, COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-19 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 314 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 1973). Colorado pikeminnow were taken from Lake Havasu in the 1970s. Populations in the upper basin are thought to be stable or increasing, with documented natural recruitment. The species is adapted to large seasonal flow variations, high concentrations of silt, turbulence, periodically low food availability and naturally variable riverine subsystems. It is typically a big river fish where the current is strong and the water heavily silt laden. Colorado pikeminnow are migratory and can utilize anywhere from 100 to 200 miles of river to complete their life cycle. Spawning takes place from spring to late summer depending on water temperatures. Larva and juvenile pikeminnow can drift 60 to 150 miles from spawning beds into nursery areas where they mature to a size that mostly prevents predation (Maddux et al., 1993; Sigler and Miller, 1963). Flannelmouth sucker − The flannelmouth sucker (Catostomus latipinnis) was historically found in medium to large rivers throughout the upper and lower Colorado River drainage (Joseph et al., 1977; AGFD, 1996a). Although the flannelmouth sucker is currently widely distributed in the upper Colorado River Basin (Holden and Stalnaker 1975a, b; McAda, et al., 1994), its occurrence in the lower Colorado River Basin has become more restricted. The species’ range in the Upper Basin includes the main stem of the Colorado River, numerous tributaries that drain a large portionrof r te io Colorado and Utah, and the San Juan River drainage in New Mexico and tUtah.nIn the Lower Basin, he I 017 of pt. of suitable 9, 2 (Sublette et 2habitat the flannelmouth sucker occurs only in localized areas . De ber al., 1990). Populations in the Lower Basin occur in ovem Colorado River, Virgin ion v N the Little Nat d Canyon, and immediately below Davis River, Colorado River in Glen ajo v Canyon, iGrandon ve Na Dam, and severalted intributariesarch Colorado River above Lake Mead (AGFD, small , to the ci 864 1996a; Valdez and Carothers, 1998). 4-16 1 No. Flannelmouth suckers typically require medium to large flowing streams and react poorly to impounded habitats or habitats influenced by impoundments (Minckley, 1973), and the artificial thermal regime created by impoundments. Subadult flannelmouth suckers in the Grand Canyon use sheltered shoreline habitats, backwaters, and tributary inflows (Valdez and Ryel, 1995). Conversely, adults can be found in a variety of mainstem habitats, including: tributary mouths, vegetated shorelines, midchannel cobble bars (Valdez and Ryel, 1995), eddies (Holden and Stalnaker, 1975a; and Valdez and Ryel, 1995) and riffles (Holden and Stalnaker, 1975a). Spawning can take place from spring to early summer and is often preceded by an upstream migration. Since 1986, the AGFD has conducted yearly monitoring of flannelmouth sucker populations in the Colorado River from Lees Ferry downstream to Lake Mead. The Glen Canyon Monitoring and Research Center (1998) has funded monitoring and research activities for this species. The objective of this program is to provide the knowledge base required to implement ecosystem management strategies within an adaptive management framework. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-20 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 315 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Humpback chub − Endemic to the Colorado River, the humpback chub (Gila cypha) inhabits the canyon-bound sections of the Colorado, Green and Yampa rivers, with high fidelity for particular localized sites. Young are not known to widely disperse. The historical abundance and distribution of the fish is not well known. Designated critical habitat includes the Colorado River from Nautiloid Canyon to Granite Park in the Grand Canyon, and the lower eight miles of the Little Colorado River, including its confluence with the Colorado River. The largest population still extant is found in and near the Little Colorado River within the Grand Canyon (Maddux et al., 1993; Valdez and Ryel, 1995). This population uses the Little Colorado River for spawning and rearing. The possibility exists that humpback chub found in the Middle Granite Gorge and lower Grand Canyon may represent a separate population (Reclamation, 1996a). Humpback chub becomes reproductively active between May and July depending on location and the hydrograph. Males become reproductively mature within three years. Spawning occurs during the highest spring flows when water temperatures approach 68°F (20°C) over cobble or gravel surfaces. Larvae tend to utilize silty bottom habitats. Later, humpback chub utilize a variety of habitats within a boulder strewn canyon environment (i.e., pools, riffles and eddies). They move between habitats dependent on life history needs and natural habitat change (NPS, 1998). r terio Ininvertebrates and Young humpback chub feed mainly from the bottom eatingthe of small , 2017 pt.also feed 29floating aquatic and diatoms. Adults also feed mainly from the bottom but . De e ber on terrestrial insects (SWCA, 1997; Valdezion v and Ryel, 1995;m at Nov Wydoski, 1995). ajo N ived on av Razorback sucker d The razorback ch − in N 4, ar sucker (Xyrauchen texanus) was formerly the most cite 1 of 6 widespread and abundant 68the big-river fishes in the Colorado River. In the lower 14basin, razorbacko. N sucker apparently began to decline shortly after impoundment of Lake Mead in 1935. Today the species occupies only a small portion of its historical range, and most occupied areas have very low numbers of fish. Critical habitat for the razorback sucker includes Lake Mead and Lake Mohave, and the river reach between them. It also includes the Colorado River and its 100-year floodplain from Parker Dam to Imperial Dam. Reclamation's BA includes a detailed discussion of this species occurrence and requirements (Reclamation, 2000). In Lake Mead, the fish were abundant for many years after the reservoir filled, but declined during the 1960s and 1970s. The current population in Lake Mead is estimated to be less than 300 fish. The capture of a small number of juvenile adults since 1997 along with recent capture of larval razorback sucker in the spring of 2000 (Holden, Personal communication) indicates some successful recruitment is taking place. There are two populations of razorback sucker in Lake Mead in Las Vegas Bay and Echo Bay. A five-year study is underway to determine population size and movements of this fish and to determine why there is a small number of fish able to recruit, thus enabling a small number of razorback sucker to persist in Lake Mead. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-21 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 316 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 The razorback sucker is a large fish, reaching over two feet in length and eight pounds in weight. Reproduction in the lower basin has been studied in Lake Mead and Lake Mohave. Spawning in Lake Mohave typically begins in January or February, while in Lake Mead it begins slightly later (Jonez and Sumner, 1954). Spawning typically runs 30 to 90 days at water temperatures ranging from 55°F to 70°F (13°C to 21°C). Spawning areas tend to be wave-washed, gravelly shorelines and shoals. Fish spawn in water from three to 20 feet in depth with the majority of fish in the five- to 10-foot range. Razorback suckers apparently spawn continuously throughout the spawning season, with females releasing only a portion of their gametes at each event. Spawning occurs both day and night on Lake Mohave (Reclamation, file data). Eggs hatch in five to 10 days depending on water temperature. Optimal hatching success is around 68°F (20°C); hatching does not occur at extremes of cold or hot (50°F or 86°F; 10 C to 30 C) (Marsh and Minckley, 1985). Larvae swim up within several days and begin feeding on plankton. Juvenile razorback suckers in lakeside rearing ponds hide during the day in dense aquatic vegetation and under brush and debris and in rock cavities (Reclamation, 1996a, 2000). Most of the remnant populations of razorback sucker are found in Lake Mead and Lake Mohave (Reclamation, 2000). They are considered rare in the Grand Canyon and have o data). been documented in Lake Powell as recently as 1999 (Reclamation, file r nteri by non-native Spawning success has been limited by the predation of eggshe Iyoung017 and of t ,2 ept. ber 2sucker that have been species. Currently, efforts are being made to introduce razorback 9 .D v raised in areas free of predators into Lake n to vem NatioMohaveNohelp establish a larger population n of breeding adults, and continued studyiofed o the persistent population in Lake Mead is vajo in Na 4, arch v planned (Reclamation, 2000). d ite 6 c 168 . 143.8.4 ENVIRONMENTAL CONSEQUENCES No This section evaluates the potential effects on special-status species and their habitat that could occur as a result of implementation of the interim surplus criteria alternatives under consideration. This section is divided into three main special-status species categories: plants, wildlife and fish. For each category, the potential effects under baseline conditions are presented first, followed by a discussion of the alternatives as compared to baseline conditions. 3.8.4.1 EFFECTS ON SPECIAL-STATUS PLANT SPECIES Only four plant species would potentially be affected by hydrological changes associated with the interim surplus criteria alternatives: Geyer’s milkvetch, Grand Canyon evening primrose, Las Vegas bear poppy and sticky buckwheat. 3.8.4.1.1 Baseline Conditions Geyer’s milkvetch, which occurs along the shoreline of Lake Mead, is mainly threatened by loss of habitat from inundation as a result of rising water levels at Lake COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-22 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 317 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Mead, invasion of shoreline (beach) habitat by tamarisk and arrowweed, and possibly trampling and grazing by burros. Shoreline recreation does not currently appear to be a major threat to this species because the beaches where it occurs do not receive heavy recreational use. This species would be affected by variations in Lake Mead surface elevations if suitable habitat were inundated. Baseline conditions indicate a decreased potential over time for such inundation to occur. If lake levels decline, exposing sand dune habitat and sandy soils, the species could benefit. However, if these areas are colonized by tamarisk after being exposed, there would be no net benefit. Grand Canyon evening primrose are found in beach habitat within the Grand Canyon. The beach habitat in the Grand Canyon is often invaded by riparian vegetation and is also utilized by recreationists, which results in adverse conditions for Grand Canyon evening primrose establishment. To the extent that beach habitat is altered by releases from Glen Canyon Dam, this species is covered under the Glen Canyon Dam ROD (1996) and Adaptive Management Program. Indirect effects to the habitat for this species may, however, result from fluctuations in Lake Mead pool elevations. Under baseline conditions, Lake Mead elevations are projected to decline over time. Reductions in Lake Mead elevations would likely result in an increase in exposed beach habitat in the lower Grand Canyon to Lake Mead that would potentially provide more r suitable habitat for Grand Canyon evening primrose. terio 7 he In of Lake Mead shoreline. As . the t r 29, 201 pt Las Vegas bear poppy occurs along the lower levels of . De embe with the Geyer’s milkvetch, this speciesion v benefit from lower water levels at Lake would at Nov Mead and would be adversely ajo N byed on affected v any increases in water levels. Benefits of i Nav lower surface elevations would bearch if invasion of exposed areas by tamarisk or d in 64, negated ite c other weedy exotic plant species were to occur. 168 . 14No Sticky buckwheat is found primarily along the Overton Arm of Lake Mead with smaller, potentially significant populations occurring in the vicinity of Overton Beach, along the Virgin River Valley, and along the Muddy River. As with the other three special-status plant species discussed, the major threats to sticky buckwheat at Lake Mead are the loss of habitat from inundation as the result of rising water levels at Lake Mead, and the invasion of shoreline (beach) habitat by tamarisk and arrowweed. This species could potentially benefit from lower lake levels at Lake Mead provided the newly exposed habitat was not colonized by weedy exotic plant species. 3.8.4.1.2 Effects of the Alternatives Potential effects to special-status plant species under the each of the alternatives would be similar to baseline conditions. Each alternative would result in Lake Mead elevations that would vary from those under baseline conditions, with the Flood Control Alternative resulting in slightly higher reservoir elevations, and the Basin States, Six States, California and Shortage Protection alternatives having lower reservoir elevations as compared to baseline projections. (Section 3.3 discusses the modeling results concerning potential future reservoir elevation trends in detail.) The differences in COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-23 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 318 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 potential future Lake Mead elevations under the alternatives as compared with baseline conditions are not expected to adversely affect the special-status plant species discussed above, as lower Lake Mead elevation trends may benefit these species. 3.8.4.2 EFFECTS ON SPECIAL-STATUS WILDLIFE SPECIES Special-status wildlife species with potential to occur in the area under consideration are Arizona Bell’s vireo, bald eagle, California black rail, Clark’s grebe, Cooper’s hawk, elf owl, gilded flicker, Southwestern willow flycatcher, Yuma clapper rail and western yellow-billed cuckoo. Under baseline conditions and each of the alternatives, the water surface elevation projected for Lake Powell indicates a potential for slightly declining water levels during the first 15 years of the period of analysis. Figure 3.3-6 in Section 3.3 shows modeled Lake Powell elevations. The differences between the alternatives and baseline conditions would not affect any special-status wildlife species identified for this analysis and as a result, Lake Powell is not discussed further. 3.8.4.2.1 Baseline Conditions ior Water fluctuations of Lake Mead generally preclude development ter 7 he In of shoreline riparian vegetation, with the exception of tributary inflow areas such as the9, 201River and . of t r 2 Virgin pt . e e vegetation be Lake Mead deltas (Reclamation, 1999). WoodyD ion v riparian m to the(i.e., cottonwood at Separationv No Canyon and willow) become abundant fromN Lake Mead delta ajo below d on as lake levels declinedin Nav highhive years of 1983-1986 (Reclamation, 1995). following rc runoff a d cit for 16864, As the probabilitye declining reservoir levels increases over time under baseline projections (asNo. 14 Figure 3.3-13 in Section 3.3), an increase in the amount of shown on sediment exposed in the Lake Mead and Virgin River deltas would again create favorable conditions for establishment of woody riparian habitat. An increase in riparian habitat along the deltas would potentially benefit Arizona Bell’s vireo, Cooper’s hawk, elf owl, gilded flicker, western yellow-billed cuckoo and Southwestern willow flycatcher. The interim surplus criteria alternatives are not expected to impact these species in the river corridor below Hoover Dam to the SIB (Reclamation, 2000). The increase in the probability for Lake Mead water levels to decline under baseline projections would also increase potential for sediment exposure that may create suitable conditions for marsh vegetation to develop and/or expand at the Lake Mead and Virgin River deltas, as well as along the Colorado, Virgin and Muddy rivers above Lake Mead. This would in turn increase the amount of preferred habitat for California black rail, Clark’s grebe and Yuma clapper rail. Riparian and marsh vegetation is typically located within the shallow water table zone near the lake shoreline. Although lowering lake levels has the potential to increase the amount of riparian and marsh vegetation because of increased sediment exposure, these habitat types would only become established if lake levels do not drop excessively. If COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-24 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 319 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 the exposed sediment is too far above the water table, riparian and marsh habitat is not likely to become established. 3.8.4.2.2 Effects of the Alternatives Potential effects on special-status wildlife species would be similar to baseline conditions. Each alternative would result in Lake Mead elevations that would vary from those under baseline conditions, with the Flood Control Alternative resulting in slightly higher reservoir elevations, and the Basin States, Six States, California, and Shortage Protection alternatives having lower reservoir elevations as compared to baseline projections. (Section 3.3 discusses the modeling results concerning potential future reservoir elevation trends in detail.) Under each of the alternatives, vegetation associated with Lake Mead, including riparian and marsh habitat in the Virgin River and Lake Mead deltas, would experience changes similar to those described above under baseline conditions. Consequently, the potential for changes in special-status species’ habitat associated with Lake Mead, and the Lake Mead and Virgin River deltas under the alternatives would be similar to those described for baseline conditions above. 3.8.4.3 EFFECTS ON SPECIAL-STATUS FISH SPECIES rior Operations at Glen Canyon Dam and Hoover Dam include variouste e In programs designed 1 of th 29, 2 the7 to aid in the conservation and recovery of endangered .native species in 0 lower ept r Colorado River basin. These programs ion v. D include Sectionembe v 7 consultations under the ESA, atand ROD (1996), and the LCRMSCP. n No the Glen Canyon Dam Operationo N AMP vaj the ived o Reclamation is also d participant in rchUpper Colorado and San Juan River Basin a in Na ,a cite 1 Programs for endangered fish in the upper Colorado River Recovery Implementation6864 basin. CriticalNo. 14for all four of the endangered fish species has been designated by habitat the Service. Adverse modification of these habitats is prohibited under Section 7 of the ESA. These programs and protections will remain in effect under baseline conditions and each of the interim surplus criteria alternatives. As discussed, conditions are not favorable for endangered fish. Future baseline conditions and each of the interim surplus criteria are expected to increase, to varying degrees, the potential for reduced reservoir surface elevations. The following discuss effects of the alternatives on each of the special-status fish species. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-25 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 320 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.8.4.3.1 CHAPTER 3 Baseline Conditions Bonytail - Under baseline conditions, it is anticipated that bonytail in the Colorado River Basin and their designated critical habitat would continue to be protected under the ESA. Reclamation has consulted with the Service under Section 7 of the ESA on the operation of Glen Canyon and Hoover dams. The resulting biological opinions will remain in effect. Reservoir operations remain within historical ranges, and efforts to protect, recover, and monitor the species status would continue. The main effort to protect and conserve bonytail in the Lower Basin is the reintroduction of fingerling bonytail from the Dexter National Fish Hatchery, New Mexico that have been reared in predator-free ponds into Lake Mohave by the NFWG. The primary limiting factor for bonytail under existing habitat conditions is predation of early life stages by non-native species. This program is designed to address predation and maintain genetic stocks of bonytail. The main efforts to protect and conserve bonytail in the Upper Basin are conducted through the Upper Colorado Recovery Implementation Program (UC-RIP). This program is designed to recover the bonytail in the Upper Basin by 2010. Colorado pikeminnow - Under baseline conditions, it is anticipated rior Colorado e that pikeminnow pikeminnow would continue to be restricted to the Upper Basin.Int Colorado7 f the 9, 201 and their designated critical habitat would continue pt.be protected under the ESA. The to o r2 De mbe Colorado pikeminnow is extirpated fromon areas considered in this analysis except for all v. ove ati Lake Powell. The ability of the jColorado ed on N to successfully reproduce in a o N iv pikeminnow av Lake Powell has not beenN arc Successful spawning occurs in riverine habitats d in confirmed. h cite and16864, drift downstream to rear in sheltered environments. above Lake Powell, - larvae then 14 Survival of larvae .that drift into Lake Powell is limited by predation by non-native fish. No As development of water continues to occur in the upper basin, lower lake elevations are expected to occur. This will increase the amount of sheltered riverine habitat and indirectly benefit the survival of some larvae by preventing them from drifting into open water areas of the reservoir where the risk of predation is greater. The main efforts to protect and conserve Colorado pikeminnow in the Upper Basin are conducted through the UC-RIP, plus the San Juan River Basin Recovery Implementation Program (SJ-RIP). This program is designed to recover the pikeminnow in the Upper Basin by 2010. Flannelmouth sucker - Under baseline conditions, it is anticipated that flannelmouth sucker populations in the project area would continue to be found in riverine habitats and tributaries. The species is not well adapted to reservoir habitats and are seldom found there. The low survival of eggs and larvae in the reservoirs may be attributed to impacts from cold water temperatures or predation by non-native species. These conditions would continue to limit the reproductive success of flannelmouth sucker in the reservoirs. For flannelmouth sucker that spawn in rivers upstream of Lake Mead and Lake Powell or other inflow areas, survival of larvae that drift into the reservoirs is limited by cold water temperatures and predation of non-native fish. Lower lake COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-26 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 321 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 elevations may increase the amount of sheltered riverine habitat and indirectly benefit the survival of some larvae by preventing them from drifting into open water areas of the reservoir where the risk of predation is greater. Efforts to improve habitat conditions under the UC-RIP, SJ-RIP, Glen Canyon Dam AMP and the Lower Colorado MSCP will benefit the flannelmouth sucker. Humpback chub - Under baseline conditions, it is anticipated that humpback chub populations would continue to be restricted to riverine and tributary habitats in the Colorado River in the Grand Canyon. The humpback chub and its designated critical habitat would continue to be protected under the ESA, the 1996 ROD, flow regimes and other activities as prescribed under the 1995 biological opinion and the Glen Canyon Dam AMP. In addition to the populations of the Grand Canyon, there are five stable populations in the Upper Basin. The UC-RIP and SJ-RIP are making progress toward recovery of the species. The humpback chub is considered extirpated from all other areas within the lower Colorado River Basin. Razorback sucker - Under baseline conditions, it is anticipated that razorback sucker populations in the Lower Basin would continue to be limited primarily to Lake Mead and Lake Mohave and designated critical habitat would continue to be protected under the ESA. Spawning success has been limited by predation of eggstandor n eri larvae by nonnative fish. Efforts are currently being made by the NFWG hesupplement7 to I 201 adult of t pt. lakes er 29, river with young breeding populations of razorback suckers by stocking . De band the io at v Mohave reared in predator free ponds. Operations n Lake Novemare conducted in an effort to Nat conserve and protect razorback sucker by ed on vajo hiv controlling the amount of lake fluctuation in Na rc during the spawning season. 64five-year study of the remnant razorback sucker ited 68 A , a c Mead is scheduled to be completed by 2002. These practices are population in Lake 14-1 No. expected to continue under baseline conditions and all the interim surplus criteria alternatives. 3.8.4.3.2 Effects of the Alternatives Potential effects on the five special-status fish species discussed above would be similar to baseline conditions. Each alternative would result in Lake Powell and Lake Mead surface elevations that would vary from those under baseline conditions, with the Flood Control Alternative resulting in slightly higher reservoir elevations, and the Basin States, Six States, California and Shortage Protection alternatives having lower reservoir elevations as compared to baseline projections. (Section 3.3 discusses the modeling results concerning potential future reservoir elevation trends in detail.) Efforts toward protection and recovery of these species would continue under each of the alternatives in the same manner as describe above for baseline conditions. Potential changes in BHBF and low steady summer flow frequencies are discussed in Section 3.6 of this FEIS, and Reclamation has determined that these effects would not be likely to adversely affect special-status fish species. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.8-27 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 322 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9 RECREATION 3.9.1 INTRODUCTION The Colorado River, Lake Mead and Lake Powell provide water-based recreation opportunities that are of local, regional and national significance, as well as international interest. This recreation analysis addresses five specific recreation-related issues associated with potential effects that could result from implementation of the interim surplus criteria alternatives considered in this document. The issues addressed are potential effects to: • Reservoir marinas and boat launching and shoreline access for Lake Powell and Lake Mead; • Lake Mead and Lake Powell boating and navigation; • River and whitewater boating; • Sport fishing in Lake Powell, Lake Mead and the Colorado or i River below Inter 17 Hoover Dam; and he 20 of t ept. ber 29, • Recreational facilities operationalv. D n costs. em Natio d on Nov vajo e The interim surplus alternatives would not change the current and projected operations in Na 4, archiv d Havasu and thus would not affect recreation on those reservoirs. of Lakes Mohavete ci and 1686 14No. MARINAS, BOAT LAUNCHING AND SHORELINE 3.9.2 RESERVOIR ACCESS This section considers potential effects of the interim surplus criteria alternatives on Lake Powell and Lake Mead marinas, boat launching facilities and other important shoreline access areas. 3.9.2.1 METHODOLOGY Information in this section was compiled after review of available published and unpublished sources, and through personal communication with Reclamation, NPS and resource specialists. Thorough review of existing literature on the Colorado River provided information on reservoir recreation use for both Lake Powell and Lake Mead. Where available, the number of facilities at each marina, boat launching ramp and shoreline access area are included. From the information compiled, representative threshold pool elevations were selected for facilities, at or below which certain facilities may be rendered inoperable or relocation of facilities could be required to maintain their operation. These thresholds COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 323 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 were chosen based on either information provided in studies, communications with NPS personnel, or from comments received regarding the DEIS. Discussions of the probabilities of these thresholds occurring is detailed in the Environmental Consequences Section (Section 3.9.2.3). The probability of reservoir elevations occurring below these levels under baseline conditions and the action alternatives was identified using river system modeling as described in Section 3.3. Data generated from the river system model include the probability (represented graphically in the Environmental Consequences section) that the water level related to each alternative would be above the specified “threshold” pool elevations for each year during the period of analysis. The graphs indicate the general trend of elevation probabilities and present the incremental differences in probabilities for baseline conditions and each of the alternatives. 3.9.2.2 AFFECTED ENVIRONMENT Recreational boating on Lake Mead and Lake Powell is dependent upon access to the water via shoreline facilities such as marinas, docks and launch ramps. Fluctuation in water levels is a normal aspect of reservoir operations, and facilities are designed and operated to accommodate it. However, decreased pool elevations or rior e increased variations or rates in pool elevation fluctuation could resultthe Int in increased operation costs, 017 f temporary closures or possibly permanent closures. pt. o 29, 2 e r D be n v. ovem atioand on NMead depend on annual inflow from Reservoir pool elevations at Lake Powell d Lake ajo N Navandarchivefrom the respective dam to the Colorado the Colorado River d in upstream, outflow cit for 16864, River downstreame water deliveries. Operation of the Colorado River generally 14results in the highest pool elevations in Lake Powell in mid-summer and in Lake Mead, No. early winter. In general, pool levels in Lake Powell and Lake Mead tend to fluctuate on an annual cycle rather than on a monthly or seasonal cycle. Lake Powell historical pool fluctuations have normally ranged from 20 to 25 feet per year (Combrinks and Collins, 1992). Since operation of Glen Canyon Dam began in 1966, Lake Mead pool fluctuation has normally ranged from 5 to 25 feet per year. 3.9.2.2.1 Lake Powell Recreation Resources Lake Powell is located in the Glen Canyon National Recreation Area (GCNRA) in southern Utah and northern Arizona. Typical recreation activities that occur at Lake Powell include swimming and sunbathing, power boating, fishing, off-beach activities associated with boat trips (such as hiking and exploring ruins), house boating, personal water craft use, canoeing, kayaking, sailing, and other activities (USBR, 1995b). A carrying capacity study (NPS, 1991) provided information on the potential limits of boater use on Lake Powell. The study also showed that the average length of stay at the GCNRA is 4.5 days. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 324 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Visitation numbers for the entire GCNRA between 1990 and 1999 are provided in Table 3.9-1. The data indicate that there are seasonal variability in recreation use. The majority of use occurs in the summer months of June, July and August. The visitation numbers shown for 1995 through 1999 are considerably lower than visitation between 1990 and 1994 due to changes in NPS methods for calculating visitation. However, the seasonal pattern of visitation does not change; use remains highest in summer months. The majority of visitors to the GCNRA travel either less than 30 miles to visit (29.1 percent) or travel 121 to 240 miles (28.9 percent). This indicates that the area is used predominantly by local and regional visitors. Table 3.9-1 Glen Canyon National Recreation Area Visitation Year Jan Feb March April May June July August Sept Oct Nov Dec Total 1990 77,617 109,042 135,039 253,638 289,993 501,288 467,981 483,023 350,026 227,061 129,691 78,750 3,103,129 1991 81,875 97,120 118,182 199,462 346,764 451,674 503,752 568,030 396,785 247,982 120,822 78,442 3,210,890 1992 83,044 114,889 139,787 246,993 346,727 525,610 572,869 659,809 478,032 245,565 122,386 82,847 3,620,558 1993 60,927 1994 69,663 120,307 174,272 264,265 364,826 576,355 665,583 439,177 321,961 212,729 83,903 123,836 201,141 372,425 526,202 624,549 644,534 530,550 259,119 111,607 99,097 76,031 3,470,194 63,607 3,371,842 94,508 50,362 2,469,521 ior te89,670 48,269 2,532,087 1996 In r 17 0 f the 1997 49,954 54,401 115,523 157,249 245,000 288,742 420,927 437,846. 266,992 187,467 , 85,595 48,507 2,458,203 pt o er 29 2 e 285,105 197,673 77,247 50,315 2,467,199 1998 39,241 55,538 89,971 171,234 267,509 389,167 445,423 398,776 v. D mb ation on441,791ve No 305,006 200,457 89,799 55,503 2,667,249 1999 44,755 51,657 118,141 155,831 261,931N jo 426,744 515,641 Nava archived Source: Based on NPS data. in 4, cited 16 numbers changed in 1995. This resulted in significant reductions in visitation numbers * NPS methods for calculating visitation86 compared to prior years. 14No. * 35,814 66,553 88,414 151,369 196,905 410,610 435,840 461,431 285,118 192,597 41,303 1995 50,553 96,296 209,243 231,655 419,288 447,417 442,180 268,266 187,949 Recreation boating is the largest type of boating activity on Lake Powell, with an estimated 1.5 million boater nights per year in 1988. Although use at some of the major marinas, such as Wahweap, Hall’s Crossing and Bullfrog, decreased during a low water period in 1989, the total number of boats on Lake Powell was reported to have increased 14.5 percent by July 31, 1989, compared to the same period in 1988 (USBR, 1995b). Specific facilities and reservoir elevations important to their operation are discussed in the following sections. Map 3.9-1 depicts Lake Powell and the locations of shoreline facilities. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 325 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Map 3.9-1 Lake Powell and Associated Shoreline Recreation Facilities ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-4 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 326 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.2.2.2 Shoreline Public Use Facilities Public use facilities at Lake Powell that include water-based recreation activities are Wahweap, Dangling Rope Marina, Halls Crossing, Bullfrog, Hite, and Antelope Point. The GCNRA Proposed General Management Plan (NPS, 1979) describes the estimated capacity and development at these areas; these estimates are based on general concepts only and further detailed planning was proposed to begin after the plan’s acceptance in 1979. Table 3.9-2 summarizes the activities at each of the sites. If the actual number of improvements (boat slips, mooring buoys, houseboats, etc.) at a facility are known, it is listed in Table 3.9-2; otherwise, the presence of an improvement is indicated with a bullet (•). If an improvement does not exist, it is denoted with “N/A.” Below is a description of the shoreline public use facilities at Lake Powell. Wahweap – The facilities at Wahweap are the closest to Glen Canyon Dam, located off Interstate 89 at the mouth of Wahweap Bay. According to a study that addressed fluctuating lake levels and recreation use, the Stateline Launching Ramp at Wahweap became inoperable in 1989 when the lake elevation decreased to below 3677 feet msl (Combrink and Collins 1992). In 1993, NPS extended the Wahweap and Stateline boat ramps down to an operable level of 3612 feet msl (Henderson, 2000). erior Dangling Rope Marina – The facilities at Dangling Rope Marinant proposed to e I were of th All 2 17 . Canyon. 29,the0facilities float, t replace the facilities at Rainbow Marina in Forbidding Dep addition r e and they are only accessible by boat (NPS, 1979). In vemb to the facilities, tour n v. atiofor visits to Rainbow Bridge National No boats depart from Dangling Rope Marina ed on jo N Nava seasoniv n Monument during the irecreation, arch (NPS, 1993). There are no known reservoir cited would64 surface elevations that -168 impair operation of this facility. No. 14 Halls Crossing – The facilities at Halls Crossing are located off Utah Highway 276 on the east shore of Lake Powell, across the bay from Bullfrog Marina. According to a study that addressed fluctuating lake levels and recreation use, the Halls Crossing Ferry Ramp became inoperable in 1989 when the lake elevation decreased to below 3675 feet msl (Combrink and Collins, 1992). In 1993, NPS extended the boat ramp down to an operable level of 3612 feet msl (Henderson, 2000). Bullfrog – The facilities at Bullfrog are located midway up Bullfrog Bay, off of Utah Highway 276 and across the bay from Halls Crossing. According to a study that addressed fluctuating lake levels and recreation use, the Bullfrog Ferry Ramp became inoperable in 1989 when the lake elevation decreased to below 3675 feet msl. In addition, the Bullfrog Utility Service became inaccessible when the lake elevation decreased to below 3670 feet msl (road access was also unavailable at the slips) (Combrink and Collins, 1992). In 1993, NPS extended the boat ramp down to an operable level of 3612 feet msl (Henderson, 2000). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 327 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.9-2 Lake Powell Shoreline Public Use Facilities Facility Wahweap Dangling Rope Marina Halls Crossing Bullfrog Hite Antelope Point * Lodging (rooms) 375 N/A 20 56 5 200-225 Restaurant/Snack Bar 2/1 N/A/1 •/1 1/1 N/A • Tour boats 9 N/A N/A 1 N/A 2 Boat slips 870 N/A 165 254 6 250-300 Mooring buoys 180 N/A 141 220 54 N/A Rental houseboats 175 N/A 89 112 21 60 Rental small boats 150 N/A 44 50 27 60 Dry storage 450 N/A 230 750 109 • RV park (spaces) 120 N/A 32 24 N/A 150 Marina campstore 1 1 1 1 N/A 1 Store • • 1 1 1 1 Boat repair • • • • N/A N/A gas r r t150io Parking (spaces) 2,500 N/A 300 1,575 e In e h 017 ft Campground (sites) 215 N/A 64 100 6 pt. o er 29, 2 . De e50 b m Picnic (sites) 124 N/A ion v20 N/A Nat d N/A Nov N/A n Day use N/A N/A vajoN/A e o beaches/trails in Na 4, archiv c ed 2 686 N/A Launching ramps it 1 1 1 -1 . 14N/A Airstrip N/A N/A 3,5002,100-foot, No Service station • • gas • foot, paved • 220 • N/A • 1 N/A paved Visitor center, cultural center • N/A N/A N/A N/A Ranger station • N/A • • N/A • Employee housing • • • N/A • • Concessionaire quarters 80 N/A 30 40 10 N/A Dorm units 119 6 24 96 0 N/A 7,80010,100 2,4003,100 3,4004,400 7,90010,300 2,5003,300 N/A Capacity (use per day) • Source: 2000. NPS 1979. Proposed General Management Plan and personal communication, Norm Henderson, NPS, • indicates presence of an improvement. N/A not applicable – indicates no improvement. * Facilities shown are proposed. Existing facilities include an entrance station, gravel parking area, two permanent toilets, and a boat ramp. The Navajo Nation and NPS are in the process of developing the site. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 328 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Hite – The facilities at Hite are located off of Utah Highway 95. According to a study that addressed fluctuating lake levels and recreation use, the Hite Launching Ramp became inoperable in 1989 when the lake elevation decreased to below 3677 feet msl (Combrink and Collins 1992). In 1993 NPS extended the boat ramp down to an operable level of 3612 feet msl. However, the ramp area is known to be useable down to 3630 feet msl (Henderson, 2000). Antelope Point – The facilities at Antelope Point are located off of Arizona Highway 98 on the southern side of Lake Powell. Development of Antelope Point only began recently, and data on visitation has not been collected on a formal basis. Existing facilities at the site consist of an entrance station where fees are collected, two permanent toilets, a large gravel parking area that can accommodate 220 vehicles, and a public boat ramp. The Navajo Nation, in conjunction with NPS, has plans to develop the site as a resort destination, and is in the process of selecting a master developer for the project. Facilities proposed for the site in the Development Concept Plan are listed in Table 3.9-2, above. The existing boat ramp at Antelope Point currently extends down to 3677 feet msl. NPS provided Reclamation with construction drawings for extending the boat ramp down to 3620 feet msl as water elevation declines. The extended boat ramperior allow would Int 36257 msl, houseboats and other watercraft to launch down to elevations e f th around 01 feet pt o er 29, 2 assuming about 5 feet of free board (Bishop, Personal .Communication, 2000). NPS . De b also provided Reclamation with a preliminary Antelopeem Marina layout drawing ion v Nov Point at for reservoir elevation of 3600ajo N ved on not been established that a marina v feet msl, but it has in Na 4, archi would be operableed this level. t at ci 1686 . 14- Monument – The Rainbow Bridge National Monument is Rainbow Bridgeo N National located on the south shore of Lake Powell and is bounded on three sides by the Navajo Reservation near the Utah/Arizona border. The facilities at the monument include courtesy docks, restrooms, a floating walkway, and a floating interpretive platform. Trails from the dock lead to viewing areas. One viewing area is used when Lake Powell is below the full-pool elevation of 3700 feet msl, and the other is used when the reservoir is at full-pool elevation. The docks and trail system are designed to accommodate lake level fluctuations allowed in the operation of Glen Canyon Dam and powerplants (from 3490 feet msl to 3700 feet msl) (NPS, 1993). If the lake levels fall below 3650 feet msl, the dock facilities would be moved and the old land trail through Bridge Canyon (submerged at full pool) would be hardened and used for access. The floating walkway and interpretive platforms would be removed and stored. The courtesy docks would be connected to the land trail with a short walkway (NPS, 1990). However, large quantities of silt that have been deposited where Bridge Creek flows into Lake Powell could create access problems at low water surface elevations. The large silt flats are difficult to cross with floating walkways; special construction techniques may be required to bridge these areas. At some lake elevations, it may be infeasible to maintain water access to the monument (NPS, 1993); however, the specific elevation is not known. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 329 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 When Lake Powell is operated below 3700 feet msl, some of the Rainbow Bridge National Monument is within a high hazard flash flood area. The 100- and 500-year flood elevations in Bridge Creek are estimated to be 7.5 feet and 10 feet above the creek channel, respectively. For the area well upstream of Lake Powell, the trail follows the creek and is above both the 100- and 500-year floodplains. However, the trail route in the transition zone between the reservoir and creek, along the lake’s edge, could be subject to water surface elevation increase, surface turbulence, and significant velocities, depending on the lake elevation at the time of flooding and the magnitude of the flood. For the lake itself, there would be little or no discernable water surface increase and the turbulence would be limited. When Lake Powell is at full operating pool, flash flood areas are well upstream of the reservoir, in the Bridge Creek Canyon drainage outside the monument. The General Management Plan for Rainbow Bridge includes a Flash Flood Mitigation Plan. In the event of combined low pool elevations and flash flood conditions, there are four components of the mitigation plan that would be put in place. These components include: 1) a wayside exhibit with information to inform visitors of possible flash flood hazards; 2) additional signage in the flood hazard zones to alert visitors where to move in case of a flood; 3) identification of evacuation and emergency measures, including chain of command responsibilities, emergency supply locations, and rior nte support facilities; and 4) installation of a warning system that would alert of the to evacuate. visitors I 2017 , t. Dep er 9 . access to mbarea2was primarily by foot. Prior to the construction of Glen Canyonon v ati Dam, Nove the Since the creation of Lake Powell, access ed on primarily by water, although the area ajo N iv is now Nav is also accessible tby trails througharch Mountain. Access to the monument is d in 64, Navajo ci e 168 restricted during the recreation season in accordance with the monument’s carrying 14capacity of 200 people at one time. In addition, access is limited daily during certain No. times of the day. Boat tours to the monument are allowed during the busier time of the day and originate at Dangling Rock Marina. All tours have an NPS interpreter on board to convey the monument’s significance. Access during quieter times of the day is limited to five to eight private boats. During the off-season, access to the monument is unrestricted except that boat tours are managed to ensure that only one tour boat at a time is present at the monument (NPS, 1993). 3.9.2.2.2.1 Threshold Elevations From the information presented above on reservoir pool elevations, three elevations, 3677 feet msl, 3626 feet msl and 3612 feet msl, were identified as representative threshold elevations below which shoreline facilities at Lake Powell could be affected. The existing boat ramp at Antelope Point extends down to elevation 3677 feet msl. This elevation is identified as one of the threshold elevations for the analysis of marinas and boat ramps at Lake Powell. As discussed above, the extended boat ramp would be operable down to 3625 feet msl. The elevation of 3626 feet msl is discussed in the boating navigation and safety section (Section 3.9.3.3.1) and is considered to be COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 330 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 representative of the threshold elevation for the extended boat ramp. Since the minimum reservoir elevation at which the Antelope Point Marina would be operable has not yet been established, the threshold elevations of 3626 feet msl (discussed above) and 3612 feet msl (discussed below) are assumed to apply to a future marina at Antelope Point. As discussed above, the boat ramps at Wahweap, Halls Crossing, Bullfrog, and Hite are designed to operate down to 3612 feet msl. It is not known what adjustments and capital improvement costs would be required if elevations were to decline to below 3612 feet msl. As such, 3612 feet msl is used in this analysis as the lower threshold elevation for marinas and boat ramps at Lake Powell. The threshold elevations of 3677 feet msl, 3626 feet msl and 3612 feet msl are used to evaluate baseline conditions and the effects of interim surplus criteria alternatives on shoreline facilities at Lake Powell in the Environmental Consequences section (Section 3.9.2.3.1). The threshold elevation of 3626 feet msl is evaluated in Section 3.9.3.3.1. 3.9.2.2.3 Lake Mead Recreation Resources rior e Lake Mead, the reservoir created by the construction of Hoover IDam, is located in the e nt 7 f thNevada 201northern Lake Mead National Recreation Area (LMNRA) in pt. o southern 29, and r . De Arizona. The LMNRA contains 1.5 million acres andvembe ion v No encompasses the 100-mile-long Nat Lake Mead, 67-mile-long Lake Mohave, the surrounding desert, and the isolated vajo fullhived on of approximately 1210 feet msl, Shivwits Plateau in d in Na At aarc pool elevation Arizona. cite 1 is 64, Lake Mead’s surface area68153,235 acres, the storage capacity is 25.9 maf and there are 695 miles of o. 14 (USBR, 1996b). Lake Mead is the largest man-made lake in N shoreline the Western Hemisphere. LMNRA receives approximately ten million visitors annually. Typical water-based recreation activities that occur on Lake Mead include: swimming, boating, houseboating, fishing, sailboarding, paddlecraft use, scuba diving (USBR, 1996b). On average, the majority of boats are personal watercraft. There may be as many as 6000 boats combined on Lake Mead and Lake Mohave during a peak recreation use weekend. At Boulder Beach, which is located near the urbanized area of Las Vegas and surrounding communities, the personal watercraft percentage may be as high as 50 percent. 3.9.2.2.4 Shoreline Public Use Facilities at Lake Mead Six marinas at Lake Mead provide boat launching facilities as well as slips and storage, fuel and boat launches. In addition, there are three boat ramps without associated marinas and one site without a boat ramp. The marinas include Boulder Beach, Las Vegas Bay, Calville Bay, Echo Bay, Overton Beach and Temple Bar. The boat ramps are located at Hemenway, Government Wash and South Cove. Pearce Ferry has no COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 331 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 boat ramp and is used as a take out by private and commercial boaters that kayak and raft the Colorado River into Lake Mead. Facilities at the six marinas are summarized in Table 3.9-3, and all of the sites are described below. If the actual number of improvements (boat slips, etc.) at the facility is known, it is included in the table; otherwise, the presence of an improvement is indicated with a bullet (•). If there are no facilities at a location, this is indicated with an “N/A” for “not applicable.” Map 3.9-2 shows the locations of both developed and undeveloped sites on Lake Mead. Table 3.9-3 Lake Mead Marina Public Use Facilities Boulder Beach/ Lake Mead Marina Las Vegas Bay Calville Bay Echo Bay Overton Beach Temple Bar Lodging • N/A N/A • N/A • Restaurant • • • • • • Facility • N/A N/A N/A N/A N/A Marina (boat slips) 750 • 650 320 • • Mooring buoys N/A N/A N/A N/A N/A N/A N/A • • N/A N/A Tour boats N/A or teriN/A • • In th•e 017 Dry storage • • •pt. of 29, 2 • De er RV Park (spaces) N/A N/An v. N/A emb 58 N/A v io Nat d on No Trailer village N/A 69 o • • • avaj rchN/Ae iv Trailer sewage dump d in N • • • • a cite 16864, Grocery/gift store • • • • - • o. 14 N Gasoline/Propane N/A • • • • Rental houseboats N/A Rental small boats N/A • • 7 111 • • • • • • • • • Parking (spaces) N/A N/A N/A N/A N/A N/A Campground (sites) Boat sewage dump 154 89 80 166 N/A 153 Picnic (sites) • • • N/A N/A N/A Showers • N/A • • • • Launching ramps • • • • • • N/A N/A N/A • N/A • Airstrip Ranger station • • • • • • Self-service laundry • N/A • • • • N/A N/A N/A N/A N/A N/A Capacity (use per day) Source: NPS, 1995 • indicates presence of an improvement N/A not applicable – indicates no improvement COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-10 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-11 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Map 3.9-2 Lake Mead and Associated Shoreline Recreation Facilities AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 332 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 333 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Recreation boating is very popular at Lake Mead, and the shoreline public use facilities are associated with boating use. Most of the facilities shown in the Table 3.9-3 were designed to operate at full pool. However, NPS has determined costs associated with adjusting facilities based on lowered lake elevations. These facilities are out of their normal operating range at pool elevations of 1180 feet msl, requiring sizable capital expenditures to restore them to working order. In addition, there are additional costs associated with any 20-foot drop below this level. Hemenway – The boat ramp facility at Hemenway is the closest to Hoover Dam and is located off Nevada Highway 166. There is one courtesy dock and a parking area (Henderson, 2000). In addition, campgrounds and a group campground are located at Hemenway. The group campground is for self-contained vehicles, such as trailers and motor homes. There are no restrooms or tables. Boulder Beach – The facilities at Boulder Beach are located off of Lakeshore Scenic Drive, just off of Nevada Highway 167 outside of Boulder City, Nevada, and include restrooms, tables and grills. There is also a group campground at Boulder Beach for tent camping only with limited vehicle parking. Las Vegas Bay – The facilities at Las Vegas Bay are located off Lakeshore Scenic ior Inter 17 Drive, just off Lake Mead Drive (Nevada Highway 167). According to a marina 0 f the worker, when the lake elevation drops below 1190 feet msl, the boat ramps and floats pt. o er 29, 2 e v. D vemb have to be readjusted. tion o N Na vajo facilityd on e at Government Wash is located off Nevada Government Wash – TheNa ramprchiv d in boat , a Highway 167. cite is 16864 There - one courtesy dock and a parking area (Henderson, 2000). 14 No. Calville Bay – The facilities at Calville Bay are located off Nevada Highway 167 on the north shore of Lake Mead, midway up Calville Bay. Echo Bay – The facilities at Echo Bay are located off Nevada Highway 167, midway up Overton Arm. Overton Beach – The facilities at Overton Beach are located off Nevada Highway 169, near the top of Overton Arm. South Cove – The boat launching facilities at South Cove are located off Aztec Wash, which is off Interstate 93 in Arizona. There is one courtesy dock, picnic facilities, and unpaved parking (Henderson, 2000). In addition, there is an airstrip approximately four miles from the facilities at South Cove (Henderson, 2000). Temple Bar – The facilities at Temple Bar are located on the south shore of Lake Mead at the end of an unnamed road off Interstate 93 in Arizona. Pearce Ferry - This area is located near Aztec Wash, which is off Interstate 93 in Arizona at the eastern end of the LMNRA. The area is a large, gravel wash with a COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 334 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 gentle slope down to the water. Vehicles are driven down to the water’s edge to load rafts and other small boats. There is parking and a year-round portable toilet, and primitive camping is allowed. There are no ramps, docks or other developed facilities at the site. The Hualapai River Runners are one of the commercial guide services that use Pearce Ferry as a take out. The River Runners conduct guided whitewater trips that put in at Diamond Creek, and float trips that put in at Quartermaster Canyon. All of these trips take out at Pearce Ferry. Comments from the Hualapai Tribe on the Draft EIS identified a Lake Mead pool elevation of 1183 feet msl as a threshold elevation for accessing the Pearce Ferry takeout. At this elevation and below, the river subdivides into smaller channels and large areas of silt and mud are exposed, prohibiting access to the take out. When Pearce Ferry is inaccessible as a takeout, boaters must continue downstream to South Cove, an additional 16 miles. This costs river runners fuel (for motorized craft), time (one to two more hours on the river) and possible safety problems (due to fatigue). For commercial boaters, the additional travel time to South Cove can also result in lost business by preventing guides from meeting river tour schedules. rior Inte f the 9, 2017 3.9.2.2.4.1 Threshold Elevations pt. o . De ember 2 nv v Natio d on N pool elevations where facilities or The description of facilities above identifies several o ajo access to facilities would Naaffected. hive Vegas Bay, 1190 feet msl was identified be v Las d in facilities arc Atrequire adjustment, but would continue to be e itwhich 6864, would as an elevation c at -1 operable. Elevation14 feet msl was identified by the NPS as the elevation at which o. 1180 N most other developed facilities would require capital expenditures, rather than just an adjustment, in order to maintain operation. Elevation 1183 feet msl was identified by the Hualapai Tribe in their comments on the DEIS as a threshold elevation for using the undeveloped Pearce Ferry site as a takeout for rafts and other whitewater boats. The DEIS evaluated the consequences of elevation 1180 feet msl for facilities at Lake Mead (Section 3.9.2.3.2). In response to the Hualapai Tribe’s comment on the DEIS regarding the threshold elevation of 1183 for Pearce Ferry, this FEIS evaluates the consequences of 1183 feet msl instead of 1180 feet msl. Therefore, 1183 feet msl is used as a representative threshold elevation for shoreline facilities and public access at Lake Mead and is used in the Environmental Consequences section (Section 3.9.2.3.2) to evaluate the effects of baseline conditions and interim surplus criteria alternatives on shoreline facilities and public access at Lake Mead. 3.9.2.3 ENVIRONMENTAL CONSEQUENCES Recreational boating on Lake Mead and Lake Powell is dependent upon access to the water via public shoreline facilities such as marinas, docks and boat ramps, as well as COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 335 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 undeveloped launch areas. Some fluctuation in water level is a normal aspect of reservoir operations, and facilities are designed and operated to accommodate it. However, decreased pool elevations or increased variations or rates in pool elevation fluctuation could result in increased operation costs, facility improvements, temporary closures, or possibly permanent closure of shoreline facilities. As lake levels fluctuate, developed facilities must be adjusted accordingly. This could require moving and relocating docks, extending utility lines associated with shoreline facilities, increasing sewage pump capacity, reducing pressure on water supply lines to boats, adjusting and relocating buoys, moving breakwater barriers and channel markers, and extending launch and dock ramps (Combrink and Collins, 1992). If lake fluctuations exceed 25 feet, special adjustments to lake facilities would be necessary, including the relocation of anchors and the extension or reduction of utility lines and cables that provide utility service to floating facilities (Combrink and Collins, 1992). In addition, if developed facilities are temporarily or permanently closed or relocated, or undeveloped sites are no longer accessible, there may be associated increases in reservoir boating congestion or longer wait times at sites that remain open. This could have an effect on boating satisfaction. The cost of relocating developed facilities in response to changes in reservoir pool elevations is discussed in Section 3.9.6. erior Int f the 9, 2017 3.9.2.3.1 Lake Powell pt. o . De ember 2 nv ov Natio d on above, pool elevations of 3677 feet As discussed in the Affected Environment sectionN ajo i N v arc asve msl and 3612 feet msliwerea d n identified h representative thresholds that are problematic ite at Lake 4, c for shoreline facilities -1686 Powell. Elevation 3677 feet msl was identified as a threshold elevation 14 the existing Antelope Point, and the NPS identified 3612 feet No. for msl as a threshold for several other facilities. These are elevations below which facility adjustments or capital improvements would be required. There are two other threshold elevations not treated directly below. Elevation 3626 feet msl has also been defined as a threshold elevation for the design boat ramp at Antelope Point. This elevation is discussed in Section 3.9.3.3.1. Facilities at Rainbow Bridge would be affected by pool elevations of 3650 feet msl or below, as described above in Section 3.9.2.2. Although specific probabilities of remaining above elevation 3650 feet msl were not determined, the probabilities that lake elevations would remain above 3650 feet msl would be between the probabilities for the threshold elevations of 3677 and 3612 feet msl, which are discussed below. Figure 3.9-1 provides an overview of the differences in end-of-July water surface elevation trends under baseline conditions and the action alternatives over the period of analysis. Figure 3.9-2 and Table 3.9-4 indicate the probability of Lake Powell elevation exceeding the threshold of 3677 feet msl in July. The probability would decrease the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-14 3500 2000 3520 3540 3560 3580 3600 3620 3640 3660 3680 3700 3720 2005 2010 2015 Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions 2020 3.9-15 Year 2025 2030 2035 2040 10th Percentile ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N 50th Percentile 90th Percentile Figure 3.9-1 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions th th 90 , 50 and 10th Percentile Values COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Surface Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2045 3612 3626 3650 3677 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 336 of 1200 0% 2000 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2005 2010 2015 2020 3.9-16 Year 2025 2030 2035 2040 2045 ior Shortage Inter Protection Alternative e of th 29, 2017 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.9-2 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percent of Values Greater than or Equal to 3677 Feet msl COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 337 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 338 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 most over the initial 15 years of the period of analysis. During this time, the probability would decline from nearly 80 percent to less than 40 percent under baseline conditions and the alternatives. During years 16 through 25 the effects of the alternatives would diminish, although the probability of exceeding elevation 3677 feet msl would remain low (roughly 30-40 percent). After year 25 there would be no discernable effect of the alternatives for the remainder of the analysis period; the probability of exceeding elevation 3677 feet msl would remain fairly low at around 40 to 45 percent. The differences between the alternatives would be most apparent during the first 15 years. The greatest difference occurs in year nine, when the difference between baseline conditions and the Shortage Protection Alternative is 19 percent. The Flood Control Alternative, with results that are nearly identical to those of baseline conditions, has the lowest probability of pool elevations dropping below 3677 feet msl, whereas the Shortage Protection and California alternatives have the highest probability. The Basin States and Six States alternatives have probabilities between the baseline conditions and the Shortage Protection Alternative. Table 3.9-4 Probabilities of Lake Powell Elevation Exceeding 3677 feet in July ior Inter 17 f the 20 Alternative pt.- o er 29, – 49 e 16 25 b Years 26 Years 1-15 v. D Years m ation on Nove N Baseline Conditions 46%-40% vajo79%-39% d 40%-34% e in Na 4, archiv Basin States Alternative 686 78%-36% 39%-34% 46%-40% cited 1 . 14No Flood Control Alternative 79%-39% 40%-35% 46%-40% Range of Probability Six States Alternative 78%-36% 39%-34% 46%-40% California Alternative 75%-33% 40%-34% 46%-40% Shortage Protection Alternative 75%-33% 39%-34% 46%-40% The probability of Lake Powell pool elevation exceeding the threshold of 3612 feet msl in July under baseline conditions and each of the alternatives is shown in Figure 3.9-3 and Table 3.9-5. The probability is greater than 70 percent throughout the period of analysis. The probability begins at 100 percent, due to the relatively full initial elevation, and declines gradually throughout the period of analysis. In general, probabilities decrease within a 10 to 15 percent range during the initial 15-year period, followed by an additional 10 to 15 percent decrease from years 16 through 34. For the remainder of the analysis period, decreases are around 5 percent. The differences between the alternatives is slight, with the greatest difference in probabilities being about eight percent. The Flood Control Alternative has the same COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-17 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 339 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 probabilities as baseline conditions and therefore would have no effect. The other alternatives have probabilities less than or equal to baseline conditions. The Shortage Protection and California Alternatives have effects similar to each other and result in the greatest departure (maximum eight percent) from baseline conditions. The Six States and Basin States alternatives are between the Shortage Protection Alternative and baseline conditions, and have a maximum departure of five percent from baseline conditions. Each of the alternatives is discussed below in more detail with respect to the patterns indicated on Figures 3.9-2 and 3.9-3 and Tables 3.9-4 and 3.9-5. Table 3.9-5 Probabilities of Lake Powell Elevation Exceeding 3612 feet in July Range of Probability Alternative Years 1-15 Baseline Conditions Years 16-34 Years 35-49 100%-91% 88%-76% 78%-72% 76%-72% r terio In 78%-72% Flood Control Alternative 100%-91% 88%-76% 017 f the pt. o er 29, 2 . De 87%-75% b Six States Alternative 100%-88% 76%-72% ion v Novem at N n jo California Alternative ava 100%-87% 85%-75% 76%-72% ed o in N 4, archiv d 6 cite 1 Alternative Shortage Protection68 100%-86% 84%-75% 76%-72% . 14o N Basin States Alternative 100%-88% COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-18 86%-75% 70% 2000 75% 80% 85% 90% 95% 100% 2005 2010 2015 2020 3.9-19 Year 2025 2030 2035 2040 California Alternative 2045 Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions 2050 CHAPTER 3 ior Inter Protection Alternative e Shortage of th 29, 2017 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N Figure 3.9-3 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percent of Values Greater than or Equal to 3612 Feet msl COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 340 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 341 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.2.3.1.1 Baseline Conditions The probability under baseline conditions that Lake Powell pool elevation is above 3677 feet msl in July decreases from 79 percent in year 1 to 39 percent in year 15. In years 16 through 25, the probability ranges between 40 and 34 percent. For the remainder of the analysis period the probability ranges between 40 and 46 percent. The early declining probabilities (for baseline conditions and alternatives) can be mostly attributed to increasing consumptive use of Colorado River water in the Upper Basin. The later rise is attributed to the suspension of equalization requirements between Lake Powell and Lake Mead (see Section 1.4.2). There is a high probability that July Lake Powell pool elevation would exceed the threshold of 3612 feet msl for the baseline condition throughout the period of analysis. Between years 1 and 15, the probability decreases from 100 percent to 91 percent. Between years 16 and 34, the probability continues to decrease gradually from 88 percent to 76 percent. For the remainder of the analysis period, the probability decreases slightly, ranging between 78 and 72 percent. The declining trend of all probabilities (baseline conditions and alternatives) can be mostly attributed to increasing consumptive use of Colorado River water in the Upper Basin. ior Inter 17 3.9.2.3.1.2 Basin States Alternative 0 f the pt. o er 29, 2 e The probability of the Lake Powell poolion v. D exceeding 3677 feet msl in July is elevation mb at Nove baseline conditions. In the slightly lower under the Basin ajo NAlternative than under States on ved Nav archifrom 78 percent to 36 percent under the Basin first 15 years, the probability decreases in , cit d probability States Alternative.eThe 16864 during this period is one percent to eight percent 14lower than under baseline conditions. In years 16 to 25, the probability decreases to a No. low of 34 percent, then rises to 39 percent. During this period, the probability is generally the same as for baseline conditions. For the remainder of the analysis period, probabilities fluctuate between 40 and 46 percent, and are generally the same as under baseline conditions. The probability of Lake Powell elevation exceeding 3612 feet msl in July under the Basin States Alternative is slightly lower than for the baseline conditions. Between years 1 and 15, the probability decreases from 100 percent to 88 percent, compared to a 91 percent probability under baseline conditions. During this period, the probability is typically up to two percent less than under baseline conditions. Between years 16 and 34, the probability continues a gradual decline to 75 percent, and ranges between zero and five percent less, but typically between zero and two percent less, than under baseline conditions. For the remaining years of analysis, the probability continues to decline to a low of 72 percent in year 2050, and is within one percent of the probability under baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-20 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 342 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.2.3.1.3 Flood Control Alternative The probability of Lake Powell pool elevation exceeding 3677 feet msl under the Flood Control Alternative is approximately the same as for baseline conditions. In the first 15 years, the probability decreases from 79 to 39 percent, and is within one percent of the probability under baseline conditions. From years 16 to 25, the probability fluctuates between 40 and 35 percent. The probability during this period is typically the same as under baseline conditions. By the end of the period of analysis, the probability remains fairly constant, between 40 and 46 percent. During this period, the probability is typically the same as under baseline conditions. The probability of Lake Powell pool elevation exceeding 3612 feet msl under the Flood Control Alternative is generally the same as that described for baseline conditions throughout the period of analysis. 3.9.2.3.1.4 Six States Alternative The probability of Lake Powell pool elevation exceeding 3677 feet msl under the Six States Alternative is very similar to the Basin States Alternative discussed above. In early years, the probability is up to seven percent less than under baseline conditions. rior In later years, the probability is generally the same as under he Inte conditions. baseline 7 01 of t 29, 2 ept. 3612rfeet msl under the Six The probability of Lake Powell pool elevation.exceedingmbe v D ation BasinNove Alternative. In early years, the States Alternative is also very similar to the on States jo N Nava ar than ed probability is up to four percent less chivunder baseline conditions. In later years, the in cited 16864 probability is typically the same ,as under baseline conditions. 14No. 3.9.2.3.1.5 California Alternative The probability of Lake Powell pool elevation exceeding 3677 feet msl is lower under the California Alternative than under baseline conditions. In the first 15 years, the probability declines from 75 percent to a low of 33 percent, and ranges from 4 to 16 percent less than under baseline conditions. In years 16 to 25, the probability increases slightly, ranging from 34 to 40 percent, and is typically the same as under baseline conditions. For the remainder of the analysis period, the probability increases slightly, remaining between 40 and 46 percent, and is always within one percent of baseline conditions. The probability of Lake Powell pool elevation exceeding 3612 feet msl under the California Alternative is slightly lower than under baseline conditions. Between years 1 and 15, the probability decreases from 100 percent to 87 percent and is from zero to eight percent less than under baseline conditions. The probability continues to decrease from 85 to 75 percent in years 16 through 34, and is up to seven percent less than under baseline conditions. For the remaining years of analysis, the probability ranges between 76 and 72 percent, and is from zero to two percent less than under baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-21 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 343 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.2.3.1.6 Shortage Protection Alternative The probability of Lake Powell pool elevation exceeding 3677 feet msl under the Shortage Protection Alternative is not significantly different from the California Alternative discussed above. In early years, the probability is up to 19 percent less than under baseline conditions. In later years, the probability is typically the same as under baseline conditions. The probability of Lake Powell pool elevation exceeding 3612 feet msl under the Shortage Protection Alternative is not significantly different from the California Alternative discussed above. In early years, the probability is up to eight percent less than under baseline conditions. In later years, the probability is within two percent of the probability under baseline conditions. 3.9.2.3.2 Lake Mead As discussed in the Affected Environment section above, a pool elevation of 1183 feet msl was identified as a representative threshold that is problematic for shoreline access at Lake Mead. Figure 3.9-4 provides an overview of the difference in end-of-year water surface elevations under baseline conditions and each of the action alternatives. ior Inter 17 Although elevations would typically be lower during the summer peak-use period, the 0 f the differences between baseline conditions and action alternatives would be similar to pt. o er 29, 2 e .D b those presented herein. vem ion v Nat d on No vajo the probability of Lake Mead elevation exceeding Figure 3.9-5 and Tablen Na indicate hive i 3.9-6 arc ited feet6864,the end of the year. As shown in Figure 3.9-5, the c the threshold of 1183 msl at -1 probability is low . 14 the period of analysis due primarily to effects associated with o over N baseline conditions. In the initial 15 years of analysis, the probabilities under baseline conditions and the alternatives decline by more than 20 percent. Shortly after year 15, the probabilities under baseline conditions and the alternatives converge near 35 percent. Subsequently, a probability of 28 to 36 percent is maintained until the end of the analysis period. Table 3.9-6 Comparison of Lake Mead Elevation Exceedance Probabilities for Elevation 1183 Feet Alternative Year 0-15 Years 16 - 49 Baseline Conditions 65%-36% 36%-29% Basin States Alternative 55%-32% 35%-29% Flood Control Alternative 65%-36% 38%-29% Six States Alternative 55%-32% 35%-29% California Alternative 45%-25% 35%-28% Shortage Protection Alternative 47%-26% 34%-28% COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-22 1000 2000 1020 1040 1060 1080 1100 1120 1140 1160 1180 1200 1220 2005 2010 2015 Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions 2020 3.9-23 Year 2025 2030 2035 2040 10th Percentile ior Inter 17 e of th 50th9, 20 Percentile pt. . De ember 2 v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N 90th Percentile Figure 3.9-4 Lake Mead End of December Water Elevations Comparison of Surplus Alternative to Baseline Conditions th th th 90 , 50 and 10 Percentile Values COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Water Elevation (feet) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2045 1170 1183 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 344 of 1200 0% 2000 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2005 2010 2015 2020 3.9-24 Year 2025 2030 2035 2040 2045 or nteri 7 IStates Alternative e of th Six 29, 201 pt. California Alternative . De ember v n Shortage Protection Alternative Natio d on Nov jo Nava archive in cited 16864, o. 14 N Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.9-5 Lake Mead End of December Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percent of Values Greater than or Equal to 1183 Feet msl COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 345 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 346 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.2.3.2.1 Baseline Conditions The probability of Lake Mead pool elevation exceeding 1183 feet msl declines from 65 percent to 36 percent under baseline conditions during the first 15 years of the analysis period. In the remaining years of the analysis period, the probability ranges between 36 and 29 percent. The general declining trend of Lake Mead elevations over time can be attributed to increases in Upper Basin use. 3.9.2.3.2.2 Basin States Alternative The probability of Lake Mead pool elevation exceeding 1183 feet msl in the first 15 years of the analysis period declines from 55 percent to 36 percent under the Basin States Alternative. The probability during this period is typically up to nine percent less than under baseline conditions. In remaining years of the analysis period, the probability ranges between 35 and 29 percent. During this period, the probability is within one percent of the probability under baseline conditions. 3.9.2.3.2.3 Flood Control Alternative The probability of Lake Mead pool elevation exceeding 1183 feet msl inr the first 15 io years of the analysis period declines from 65 percent to 36 percenttunder the Flood In er 17 he the probability ranges 20 Control Alternative. In remaining years of the analysis of t ept. period,r 29,1183 feet msl under D be between 38 and 29 percent. The probability v. exceeding elevation on of Novem atiapproximately the same as under baseline the Flood Control Alternative would be ajo N d on conditions throughout itheNav analysisvperiod. entire rchi e n a cited 16864, 14 3.9.2.3.2.4 Six States No. Alternative The probability of Lake Mead pool elevation exceeding 1183 feet msl in the first 15 years of the analysis period declines from 55 percent to 32 percent under the Six States Alternative. In remaining years of the analysis period, the probability ranges between 35 and 29 percent. The probability is nearly identical to that for the Basin States Alternative discussed above. 3.9.2.3.2.5 California Alternative The probability of Lake Mead pool elevation exceeding 1183 feet msl is lowest under the California Alternative in most years. In the first 15 years, the probability ranges between 45 and 25 percent. This is up to 26 percent lower than under baseline conditions. After year 16, the probability is within one percent of the probability under baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-25 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 347 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.2.3.2.6 Shortage Protection Alternative The probability of Lake Mead pool elevation exceeding 1183 feet msl under the Shortage Protection Alternative is nearly the same as under the California Alternative. In the first 15 years, the probability ranges between 47 and 27 percent and is up to 26 percent lower than under baseline conditions. After year 16, the probability associated with the Shortage Protection Alternative generally converges with baseline conditions and the other alternatives, similar to the California Alternative. 3.9.3 RESERVOIR BOATING/NAVIGATION This section discusses potential effects of the interim surplus criteria on reservoir boating and navigation. This includes a discussion of areas on the reservoir that could become unsafe for boating at certain elevations due to exposed rocks or other obstructions, and safe boating densities that indicate the number of boats that can safely be accommodated on the reservoirs at one time. Boating navigation and safe boating capacities on Lake Powell and Lake Mead are dependent upon water surface elevations. As lake levels decline, so does the available surface area. Hazards such as exposed rocks may become more evident,r or changes in rio for navigation patterns may be necessary. The area of the reservoirsnte he I available7 boating is t 201 also reduced, which may affect the number of boatspt. of safely operate at one time. e that can er 29, At low pool elevations, special buoys orion v. Dmayvemb to warn boaters of markers o be placed Nat d o placed navigational hazards. In addition, signs may ben N in areas that are deemed vajo hive unsuitable for navigation.Na in arc d cite 16864, 143.9.3.1 METHODOLOGY No. Description of the affected environment is based on a literature review of published and unpublished documents and maps, and personal communications with NPS staff at the GCNRA and LMNRA. Information received includes the identification of navigation issues associated with recreational boating on Lake Powell and Lake Mead, such as navigation safety and safe boating densities. Low reservoir pool elevations identified in the literature or through discussions with NPS as being of concern for reservoir boating and navigation are discussed herein. Assessment of environmental consequences associated with implementing the interim surplus criteria alternatives is based on river system modeling and probability analyses of Lake Powell and Lake Mead pool elevations exceeding identified thresholds. Safe boating capacity is another aspect of boating navigation and safety. Safe boating is one factor that can be used to assess the carrying capacity of a reservoir. To date, no determination of carrying capacity (number of boats at one time) has been made for either Lake Powell or Lake Mead. However, the NPS is currently developing a carrying capacity approach for managing water-based recreation on Lake Mead that is based on COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-26 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 348 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 the U.S. Forest Service Recreation Opportunity Spectrum system. Results of the NPS study were not available for this analysis. A safe boating density of nine acres per boat was established for the GCNRA (USBR, 1995b) at Lake Powell. The safe boating density could be used to assess the effects of the interim surplus criteria alternatives on boating safety if daily boating levels for the reservoir were available. However, there is no known information on the level of daily or peak boating use, such as whether the current boating densities on the reservoirs have approached or exceeded the safe boating density (as discussed below). Without information on current reservoir boat densities, it is not known whether future reductions in pool elevations at Lake Powell and Lake Mead would result in unsafe boating conditions. 3.9.3.2 AFFECTED ENVIRONMENT 3.9.3.2.1 Lake Powell Boating Navigation and Safety In 1986, the GCNRA developed an “Aids to Navigation Plan” for Lake Powell that identified boating safety issues on the reservoir and low pool elevations that could affect boating (NPS, 1986). The navigation system uses regulatory buoys and other or nteri 7 marking devices to warn boat operators of hazardous conditionsIassociated with 1 f the subsurface obstructions or changes in subsurface conditions that 29, 20 hazardous for pt. o er could be e safe passage. Placement of many of these n v. D devices b dependent on the lake marking em is Natio d on Nov elevation. ajo ive Nav d in 36804, arch there are several places that remain passable, cit below 686 feet msl, At pool elevationse -1 although buoys are placed for safe navigation. At elevation 3626 feet msl and 3620 feet o. 14 N msl, there are two areas on the reservoir that are closed to commercial tour boats and recreational boats, respectively, because of hazardous obstructions to navigation. One of the areas is around Castle Rock, just east of the Wahweap Marina, and the other is around Gregory Butte, which is about midway to Dangling Marina from Wahweap (as shown on Map 3.9-1). At elevation 3626 feet msl commercial tour boats leaving the Wahweap Marina heading up reservoir (east) must detour 8.5 miles around the southern end of Antelope Island. At Gregory Butte, commercial tour boats must detour 4.5 miles around Padre and Gregory Buttes (NPS, 1986). The added mileage and increased travel time makes the more popular half-day trips of the area infeasible for commercial tour boat operators. In addition, the added mileage may influence recreational boaters to remain in the area of Wahweap Bay, which can result in congestion (Henderson, 2000). In addition to buoys marking obstructions, the Aids to Navigation Plan also established a marked travel corridor to guide boat travel on Lake Powell. This primary travel corridor is the main channel of the old Colorado River bed and is marked with buoys along the entire length of the reservoir. Except for the reservoir mouth, there are no known pool elevations at which boat passage along this main travel corridor becomes restricted and affects boating. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-27 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 349 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Near the upstream end of the reservoir, where the San Juan River enters, a delta has formed that can affect river boaters coming into Lake Powell at low pool elevations. River boaters from the San Juan River paddle through Lake Powell to a location where a boat transports them 20 to 25 miles (depending on the pick-up location) to the Hite Marina. At low water surface elevations, the river boaters must travel further downstream to reach a location that is accessible to the transport company’s boat. Although this results in more miles to paddle to the takeout, there is usually enough current in the river to carry the boats. For some boaters, the added mileage is an opportunity to paddle additional rapids on the Colorado River in Cataract Canyon (Hyde, 2000). For others, the additional mileage is seen as exposure to additional navigational hazards, possibly requiring portaging of boats due to restricted channel widths and subsurface conditions. 3.9.3.2.1.1 Lake Powell Safe Boating Capacity Recreational boating is the most frequent type of boating activity on Lake Powell, with an estimated 1.5 million boaters per year. One of the most popular activities at Lake Powell is to take houseboats and motor boats for multiple day excursions to explore the reservoir. rior Inte 17 f the at 9, 2time (i.e., safe The number of boats that Lake Powell can safely accommodate 2 one 0 t. o Dep mber . Outdoor Recreation standard of nine boating capacity) is based on a 1977 Bureau v of tion amount ove surface acres per boat (USBR, ajo Na Thed on N of water storage in Lake Powell 1995b). v e directly influences thein Na area rchiv reservoir and the number of boats that can d surface 4, aof the cite 1 86 safely be on the reservoir.6Table 3.9-7 lists median July Lake Powell surface areas for baseline conditions 14 alternatives in the year 2016 and identifies the safe boating No. and capacity of the reservoir at those elevations, based on an assumed maximum safe density of nine acres per boat. The surface area of Lake Powell is reduced by approximately 9 to 10 percent for each 20-foot drop. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-28 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 350 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.9-7 Lake Powell Safe Boating Capacity at Water Surface Elevations Scenario Median Elevation in July of Year 15 (feet msl) Water Surface Area (acres) Safe Boating 1 Capacity Baseline Conditions 3665 134,600 14,956 Basin States Alternative 3664 134,100 14,900 Flood Control Alternative 3665 134,600 14,956 Six State Alternatives 3664 134.100 14,900 California Alternative 3660 130,800 14,533 Shortage Protection Alternative 3659 130,200 14,467 1 Number of boats, assuming safe density of 9 acres per boat. At full pool for Lake Powell (3700 feet msl), the surface area is 160,782 acres. Using the safe boating density of nine surface acres per boat, Lake Powell’s safe boating capacity at full storage is approximately 17,865 boats. As pool elevation decreases, the surface area available for boats also decreases. While safe reservoir boating carrying ior capacity is reduced at lower lake elevations, there may be additional shoreline camping Inter 17 0 f the available due to more exposed beaches. However, boating capacity,is more constrained pt. o er 29 2 e v. of by safe boating densities than by the availabilityD camping sites on Lake Powell mb ation on Nove (Combrink and Collins, 1992).ajo N d ive Nav d in 64, arch 3.9.3.2.2 Lake ite Boating Navigation and Safety cMead 168 14No. Similar to the navigation system on Lake Powell, regulatory buoys and other marking devices are used on Lake Mead to warn boat operators of dangers, obstructions, and changes in subsurface conditions in the main channel or side channels. As with Lake Powell, the main channel of the old Colorado River bed forms the primary travel corridor on Lake Mead and is marked along its entire length with buoys for boating guidance. In addition, regulatory buoys are placed in areas where there may be a danger for safe passage. Excursions from Lake Mead into the Grand Canyon are a popular activity. Boats entering the Grand Canyon usually launch at Pearce Ferry, South Cove or Temple Bar (refer to Map 3.9-2). There are no developed facilities at South Cove or Pearce Ferry. Points of interest in the Grand Canyon include Columbine Falls, Bat Cave, Spencer Creek, and Separation Canyon. In addition to sightseeing being a popular activity, many boaters include overnight camping stays on these excursions (USBR, 1995b). The upper arms and inflow areas of Lake Mead are considered dangerous for navigation due to shifting subsurface sediments. In the main channel of the reservoir, the Grand COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-29 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 351 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Wash Cliffs area is the beginning of dangerous navigation conditions, and no houseboats are allowed beyond this point (NPS, undated). Over the years, sediment has built up in the section of the reservoir between Grand Wash and Pearce Ferry. When lake elevations drop below 1170 feet msl, the sediment is exposed as mud flats and there is no well-defined river channel. As a result, the area is too shallow for motor boats to navigate upstream and into the lower reaches of the Grand Canyon. With fluctuating flows, even smaller crafts have a difficult time accessing the area because of the shifting nature of the channel (USBR, 1995b). Based on this information, 1170 feet msl is considered a threshold elevation for safe boating navigation at Lake Mead. While the area around Pearce Ferry is an issue for navigation at 1170 feet msl, it is also inaccessible as a take out for whitewater boaters at elevation 1183 feet msl and boaters must paddle an additional 16 miles to South Cove (Henderson, 2000). Paddling to South Cove includes paddling through the section of reservoir between Pearce Ferry and Grand Wash. (Refer to Section 3.9.2.2.3 for a description of the Pearce Ferry facility, and Section 3.9.2.3.2 for an analysis of environmental consequences associated with elevation 1183 feet msl.) erior In addition to the boating navigation issues summarized above, there are 17 e Int 0 swimmer f thVegas,Bay and safety issues at Lake Mead. At Gypsum Wash (between Las r 29 2 pt. o . De withmbe Government Wash), there are cliffs that iare popular ove recreationists for jumping into nv Nat o 1180 n N msl, the water is too shallow for o the lake. When lake elevations are belowed o feet avaj rchiv cliff jumping from thisn N i location., Another jumping spot that was poplar during the late 4 a cited levels were down is an area called “33 Hole.” This location is 1980’s when reservoir -1686 4 popular for cliff o. 1 N jumping when the lake elevation reaches 1165 feet msl. Cliff jumping at both locations is discouraged by the NPS for safety reasons (Burke, 2000). Since the activity is discouraged, the identified elevations were not considered as thresholds for evaluation of effects. 3.9.3.2.3 Lake Mead Safe Boating Capacity The LMNRA receives approximately ten million visitors annually. Of those that participate in water-based recreation, most either swim, boat, fish, sailboard, use paddlecraft, or scuba dive (USBR, 1996b). Since no boating capacity has been established for Lake Mead, the safe boating density of nine acres per boat established for Lake Powell was assumed; safe boating capacities were determined based on reservoir elevation/surface area relationships. There is no daily or peak boating use information available to establish the relationship between actual boating densities and the safe boating capacity values shown below in Table 3.9-8. This table shows Lake Mead surface area under the predicted pool elevations for baseline conditions and the alternatives at the end of 2016, and identifies the safe boating capacity of the reservoir based on an assumed maximum safe density of nine acres per boat. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-30 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 352 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.9-8 Lake Mead Safe Boating Capacity at Water Surface Elevations Scenario Median Elevation at End of Year 15 (feet msl) Water Surface Area (acres) Safe Boating 1 Capacity Baseline Conditions Basin States Alternative Flood Control Alternative Six State Alternatives California Alternative Shortage Protection Alternative 1162 1143 1162 1145 1131 1130 120,200 108,100 120,200 109,400 102,100 101,700 13,356 12,011 13,356 12,156 11,344 11,300 1 Number of boats, assuming safe density of 9 acres per boat. At full pool for Lake Mead, the operating surface area is 153,235 acres. Using the safe boating density of nine surface acres per boat, Lake Mead’s safe boating capacity at full storage is approximately 17,000 boats. As pool elevation decreases, the safe boating capacity also decreases. 3.9.3.3 ENVIRONMENTAL CONSEQUENCES rior Boating navigation and safe boating densities on Lake Powelle Inte Mead are and Lake 17 f th 20 . ofluctuate,9hazards, such as dependent upon water surface elevations. As lakeept levels r2 , v. D mbe exposed rocks at lower pool elevations tor different navigational patterns at higher a ion on Nove special buoys or markers may N elevations, may become evident. oAt low pool elevations, vaj Nanavigational ed chiv hazards. In addition, signs may be placed in be placed to warn boaters of in 4, ar ited for navigation. c areas deemed unsuitable1686 - No. 14 Assessment of environmental consequences of the alternatives on boating navigation and safety is based on river system model output, described in detail in Section 3.3. The probability of effects under baseline conditions and the alternatives was determined through identifying the probability of exceeding a representative “threshold” pool elevation during the period of analysis. The selection of the threshold pool elevation is based on the known boating navigation issues discussed in the Affected Environment section above. The probabilities of the reservoirs remaining above the identified threshold elevations are identified for baseline conditions and the interim surplus criteria alternatives, and differences between probabilities under baseline conditions and alternatives are compared. In addition to navigation issues that occur at low pool elevations, the number of boats that can safely be accommodated on the reservoir at one time (safe boating capacity) is also a reservoir boating issue. As discussed previously, the lack of boating use data and spatial modeling of the effects of the alternatives on shoreline conditions precludes a quantitative or qualitative assessment of the impacts associated with the alternatives. In general, as pool elevations change, so does the reservoir surface area and the number of boats that can safely be accommodated on the reservoir. Therefore, the alternatives that COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-31 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 353 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 result in the greatest potential for lower surface elevations would tend to increase the likelihood of exceeding safe boating densities. Without current and projected boating use levels for comparison to surface areas under the alternatives, it cannot be determined whether the change in available surface area would result in an exceedance of the calculated safe boating capacities shown in Tables 3.9-7 and 3.9-8, so environmental consequences related to safe boating capacity are not analyzed further. 3.9.3.3.1 Lake Powell For Lake Powell boating navigation, a reservoir pool elevation of 3626 feet msl was identified as a representative threshold in Section 3.9.3.2.1. Figure 3.9-1 (presented previously) shows elevation trends for baseline conditions and the alternatives over the period of analysis. In addition, as discussed in the section on shoreline facilities (Section 3.9.2.2.2), elevation 3626 feet msl is also close to the elevation for a new proposed boat ramp at Antelope Point, which will extend down to 3620. Using an assumption of six feet for freeboard, the environmental consequences associated with elevation 3626 for navigation are applicable to the future operability of the proposed ramp at Antelope Point. rior Inte 1 f the 3626 feet7 under Figure 3.9-6 depicts the probability of pool elevations .exceeding29, 20 msl pt o . De ember v baseline conditions and each of the alternatives. Table 3.9-9 presents a comparison of tion n Nov the probabilities associated withjo Na1 through 15, 16 through 28, and 29 through 49. years va ed o The probability decreasesNa 100chiv percent) during the analysis period under in (from , ar to 65 cited all 8 the baseline conditions and-16of64 alternatives. The probability is greatest for baseline conditions andNo. Flood Control Alternative, and least for the California and Shortage the 14 Protection Alternatives. The Six States and Basin States alternatives have probabilities between the others. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-32 60% 2000 65% 70% 75% 80% 85% 90% 95% 100% 2005 2010 2015 2020 3.9-33 Year 2025 2030 2035 2040 2045 Flood Control Alternative ior Six States Inter Alternative e 17 of th California Alternative t. 9, 20 p 2 v. De vember Shortage Protection Alternative n Natio d on No jo Nava archive in cited 16864, o. 14 N Basin States Alternative Baseline Conditions Figure 3.9-6 Lake Powell End of July Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to 3626 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 354 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 355 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.9-9 Probabilities of Lake Powell Elevation Exceeding 3626 feet in July Projected Condition Years 1 - 15 Range of Probability Years 16 - 28 Years 29 - 49 Baseline Conditions 100%-86% 84%-72% 72%-65% Basin States Alternative 100%-80% 80%-71% 71%-65% Flood Control Alternative 100%-86% 84%-72% 73%-65% Six States Alternative 100%-80% 80%-71% 71%-65% California Alternative 100%-75% 73%-69% 71%-65% Shortage Protection Alternative 100%-74% 74%-69% 71%-65% 3.9.3.3.1.1 Baseline Conditions The probability of Lake Powell pool exceeding the safe boating navigation elevation of 3626 feet msl in July gradually decreases from 100 percent to 65 percent under baseline conditions during the entire period of analysis. The probability decreases more slowly under baseline conditions and the Flood Control Alternative than under the other ior Inter decreases from alternatives. In the first 15 years of the analysis period, thethe f probability 017 100 to 86 percent. From years 16 to 28, the probability o pt. decreases 9, 2 84 to 72 percent. r 2 from De mbe For the remainder of the analysis period,on v. the probability continues to decrease, declining ati Nove from 72 to 65 percent. ajo N ed on v in Na rchiv ited 6864, a c 3.9.3.3.1.2 Basin States Alternative -1 o. 14 N The probability of Lake Powell pool elevation exceeding 3626 feet msl gradually decreases from 100 percent to 65 percent under the Basin States Alternative during the entire period of analysis. During the first 15 years, the probability declines more rapidly than under baseline conditions, dropping from 100 to 80 percent. The probability in year 15 is six percent less than under baseline conditions. Between years 16 and 28, the probability begins to converge with the probabilities of baseline and the other alternatives, and ranges between 80 and 71 percent. During this period, the probability is up to 7 percent less than under baseline conditions. For the remainder of the analysis period, the probability is similar to baseline conditions and the other alternatives, continuing to decline to a low of 65 percent. 3.9.3.3.1.3 Flood Control Alternative For the Flood Control Alternative, the probability of Lake Powell pool elevation exceeding 3626 feet msl is practically the same as for baseline conditions throughout the analysis period. As shown in Figure 3.9-6, there are only three years in which the probability is different (within one to two percent) from baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-34 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 356 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.3.3.1.4 Six States Alternative The probability of Lake Powell elevation exceeding 3626 feet msl under the Six States Alternative is identical to the probability under the Basin States Alternative in all but four years, when there is a one percent difference. 3.9.3.3.1.5 California Alternative The California Alternative results in the lowest probability of Lake Powell pool elevation exceeding 3626 feet msl. The probability decreases from 100 to 75 percent in the first 15 years of the analysis period. Between years 16 and 28, the probability begins to converge with the probabilities under baseline and the other alternatives, ranging between 73 and 69 percent. For the remainder of the analysis period, the probability is similar to baseline conditions and the other alternatives, continuing to decline to a low of 65 percent. During these three periods, the probability is up to 14 percent, 12 percent and 5 percent, respectively, below the probability under baseline conditions. 3.9.3.3.1.6 Shortage Protection Alternative ior ter For the Shortage Protection Alternative, the probability of Lake IPowell pool elevation 7 he n Alternative exceeding 3626 feet msl is nearly the same as underpt. of t the California9, 201 2 throughout the analysis period. The probabilityD up toember v. ise ion of theNov 12 percent less than under 16 baseline conditions during the first Nat ajo 15 yearsd on analysis period. Between years and 28, the probability n Navto convergee begins chiv with the probabilities under baseline i 4, ar ited alternatives, and is up to 11 percent less than under baseline conditions and c other 686 the -1 conditions. For the 14 o. remainder of the analysis period, the probability is within 5 percent N of baseline conditions. 3.9.3.3.2 Lake Mead A reservoir pool elevation of 1170 feet msl was identified as the representative threshold for boating navigation at Lake Mead, as described in Section 3.9.3.2.2. Figure 3.9-7 depicts the probability of Lake Mead end-of-December pool elevations exceeding 1170 feet msl for baseline conditions and the alternatives. Table 3.9-10 compares the probabilities associated with years 1 through 15, years 16-22, and years 23 through 49. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-35 0% 2000 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2005 2010 2015 2020 3.9-36 Year 2025 2030 2035 2040 2045 ior Inter 17 e 20 of thShortage Protection Alternative ept. ber 29, D m n v. atio on Nove N vajo hived Na d in 64, arc cite 168 o. 14 N California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions Figure 3.9-7 Lake Mead End of December Water Elevations Comparison of Surplus Alternatives to Baseline Conditions Percentage of Values Greater than or Equal to 1170 Feet COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Percent of Values Greater than or Equal to AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 357 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 358 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.9-10 Probabilities of Lake Mead End-of-December Elevation Exceeding 1170 feet Range of Probability Projected Condition Years 1 – 15 Years 16 - 22 Years 23 - 49 100%-45% 45%-38% 40%-34% Basin States Alternative 99%-38% 40%-38% 40%-34% Flood Control Alternative 100%-46% 47%-39% 42%-34% Six States Alternative 100%-39% 40%-38% 40%-34% California Alternative 80%-33% 40%-36% 40%-34% Shortage Protection Alternative 80%-34% 40%-35% 40%-34% Baseline Conditions Under baseline conditions and the alternatives, the probability of Lake Mead pool elevation exceeding 1170 feet msl declines during the interim period, then stabilizes for the remainder of the period of analysis. The probability is greatest for baseline ior conditions and the Flood Control Alternative, and least for the California and Shortage Inter 17 Protection Alternatives. The Basin States and Six States alternatives 20 probabilities have f the pt. o er 29, e between the others. b v. D n em Natio d on Nov 3.9.3.3.2.1 Baseline Conditionso vaj e in Na 4, archiv d ite 6 The probabilitycof Lake 168 pool elevation exceeding the safe boating and navigation - Mead . 14msl at the end of the year declines from 100 to 34 percent under No elevation of 1170 feet baseline conditions throughout the entire period of analysis. Probabilities decrease more slowly under baseline conditions than under all alternatives except for Flood Control. In the first 15 years of analysis, the probability declines from 100 to 45 percent. Between years 16 and 22, the probability continues to decline from 45 to 38 percent, as the alternatives converge with baseline conditions. For the remainder of the analysis period, the probability under baseline conditions is similar to the alternatives, ranging between 40 and 34 percent. 3.9.3.3.2.2 Basin States Alternative The probability of Lake Mead pool elevation exceeding 1170 feet msl declines from 99 to 34 percent throughout the entire period of analysis for the Basin States Alternative. As with most other alternatives, the decrease occurs during the interim period and occurs more quickly than under baseline conditions. In the first 15 years of the analysis period, the probability drops from 99 percent to 39 percent and is typically up to 13 percent less than under baseline conditions. Between years 16 and 22, the probability stabilizes and converges with baseline conditions. The range of probability is from 40 to 38 percent, and is up to five percent less than under baseline conditions. For the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-37 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 359 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 remainder of the analysis period, the probability is within one percent of baseline conditions, ranging between 40 and 34 percent. 3.9.3.3.2.3 Flood Control Alternative The probability of Lake Mead pool elevation exceeding 1170 feet msl under the Flood Control Alternative is typically up to two percent greater than under baseline conditions. In the first 15 years of analysis, the probability decreases from 100 to 46 percent, and is within one percent of baseline conditions. Between years 16 and 22, the probability continues to decline, ranging between 47 and 39 percent, and is typically one percent greater than under baseline conditions. For the remainder of the analysis period, the probability is up to 4 percent greater than baseline conditions, ranging between 42 and 34 percent. 3.9.3.3.2.4 Six States Alternative The effects of the Six States Alternative would be nearly the same as those for the Basin States Alternative. In the first 15 years of the analysis period, the probability of Lake Mead elevation exceeding 1170 feet msl is typically up to 11 percent less than under baseline conditions. Between years 16 and 22, the probability stabilizesrand converges rio of with baseline conditions. The probability is typically within twonte he I percent17baseline 2 of t conditions. For the remainder of the analysis period, tthe probability is 0 ep . ber 29, within one . D andempercent. percent of baseline conditions, ranging between 40 v 34 ion v No Nat vajo hived on 3.9.3.3.2.5 Californian Na i Alternativerc ited 6864, a c 14- Mead pool elevation exceeding 1170 feet msl under the The probability of.Lake 1 No California Alternative is similar to that under the Shortage Protection Alternative and less than under baseline conditions and the other alternatives. In the first 15 years, the probability drops from 80 to 33 percent, then rises to 35 percent. The probability is up to 31 percent less than under baseline conditions. Between years 16 and 22, the probability rises slightly and converges with baseline conditions and the other alternatives. The probability ranges from eight percent less than to the same as under baseline conditions. For the remainder of the analysis period, the probability is within one percent of baseline conditions. 3.9.3.3.2.6 Shortage Protection Alternative The effects of the Shortage Protection Alternative are very similar to those described for the California Alternative. The probability of Lake Mead pool elevation exceeding 1170 feet msl is generally within one percent of the probability under the California Alternative throughout the period of analysis. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-38 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 360 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.9.4 CHAPTER 3 RIVER AND WHITEWATER BOATING The Grand Canyon Protection Act directs the Secretary to operate Glen Canyon Dam in accordance with the additional criteria and operating plans specified in Section 1804 of the Act, and to exercise other authorities under existing law in such a manner as to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established, including but not limited to natural and cultural resources and visitor use. The Glen Canyon Dam Adaptive Management Program (AMP) was established as a Federal Advisory Committee to assist the Secretary in implementing the Grand Canyon Protection Act. As discussed in Section 3.2.2, the AMP provides a process for assessing the effects of current operations of Glen Canyon Dam on downstream resources and using the results to develop recommendations for modifying operating criteria and other resource management actions. While the interim surplus criteria could have an influence on releases from Glen Canyon Dam, such releases will be governed by the criteria in the Record of Decision, which was developed in full consideration of both the safety and quality of recreational experiences in Glen and Grand Canyons. A summary of the Glen Canyon Dam Record of Decision has been included as Attachment D of this FEIS. erior nt the I f criteria 9, 2017 would The only effect that implementation of the interimept. o D surplus er 2 alternatives have on whitewater boaters would be theon v. possibilityovemb pool elevations in Lake of lowered ati Nboaters onn NSan Juan River often end their trips o Powell and Lake Mead. Whitewater e avaj levels in d o the at Lake Powell. Whilen N i decreased archiv Lake Powell have effects on take out points d , 4 cite in the Colorado and San1686 4- Juan Rivers, they also may expose additional rapids in Cataract 1 Canyon, which would expand whitewater rafting opportunities. Section 3.9.3.2.1 No. discusses boaters entering Lake Powell. Whitewater boaters on the Colorado River often end their trips in Lake Mead. Pearce Ferry is the preferred Lake Mead take out for boaters, but it may not be accessible when the reservoir pool elevation is below 1183 feet msl. An analysis of this elevation is presented in Section 3.9.2.2. A take out is also available at Diamond Creek, upstream of Lake Mead at the Hualapai Reservation. The Hualapai Tribe maintains the take out area and road and charges a fee for take out. The Hualapai Tribe also conducts river trips from Diamond Creek (on the Colorado River) to Pearce Ferry. This concession may be affected if trips encounter changes in availability of the Pearce Ferry take out. 3.9.5 SPORT FISHING This section considers potential effects of the interim surplus criteria alternatives on recreational opportunities associated with sport fishing at Lake Powell, Lake Mead and Lake Mohave (between Hoover and Davis Dam). Sport fishing in the Colorado River between Glen Canyon Dam and Lake Mead will not be affected by the interim surplus criteria action due to the protection afforded by the Adaptive Management Program (see COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-39 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 361 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Section 3.9.4). Fluctuations in flows between Hoover Dam and the SIB under the alternatives would be within the historical operating range of the river. Therefore, changes in flows under the alternatives would not affect recreation within these areas. Adverse effects on sport fisheries from potential changes in water temperature below Hoover Dam would not be expected, as discussed in Section 3.7.3. 3.9.5.1 METHODOLOGY The discussion of the affected environment for reservoir fishing is based on a review of published documents. Much of this information was derived from the following sources: for Lake Powell, the Fish Management Plan, Glen Canyon National Recreation Area (NPS, 1996); and for Lake Mead, the Desert Lake View Newspaper, Fall/Winter 1999. In addition, creel information and angler fishing data has been obtained from state agencies in Utah, Arizona, and Nevada responsible for managing the fisheries resources at Lake Mead, Lake Powell, and Lake Mohave. Assessment of potential impacts on sport fishing in Lake Powell, Lake Mead and Lake Mohave is based on information presented in other sections of the document regarding sport fishery populations (Section 3.7), reservoir shoreline facilities (Section 3.9.2) and reservoir navigation (Section 3.9.3). There were no specific reservoir ipool elevation or Inter 7 thresholds related to sport fishing identified from the literature reviewed.1Catch rates 0 f the for reservoir fishing are assumed to be directly related.to reservoir9, 2 discussed in pt o er 2 habitat e D mb Section 3.7, Aquatic Resources. Fishingon v. i satisfaction v assumed to be directly related ataccesson theois e via shoreline facilities, andto N water the general recreation issues ofajo N v boating ed to boating navigation potential for , archi or reservoir detours due to low pool elevations. in Na 4hazards v ited 3.7, 6 As discussed incSection 168catch rates are not expected to be affected by fluctuations 4in pool elevations.. 1 No 3.9.5.2 AFFECTED ENVIRONMENT 3.9.5.2.1 Sport Fishing in Lake Powell As discussed in Sections 3.7 and 3.8, native Colorado River species have not done well in the reservoir environment. While some native species may spawn in the reservoir, it is believed that the majority of young are eliminated by sport fish predators. The predominant sport fishery in Lake Powell revolves around striped bass. The striped bass depend on threadfin shad as a food source, so it is critical to maintain a balanced shad population for the striped bass. The threadfin shad in Lake Powell are at the northernmost portion of their range and are very sensitive to fluctuations in water temperature. In addition to striped bass, Lake Powell supports largemouth and smallmouth bass, walleye, channel catfish, bluegill, and black crappie. Lake Powell has been stocked with fish almost annually, beginning in 1963 (NPS, 1996). COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-40 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 362 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Lake Powell is a popular fishing destination. Over three million people visit the GCNRA annually, and those that fish spend a total of close to two million angler hours in pursuit of a variety of sport fish. Nearly all anglers fish by boat due to the cliff-like canyon walls of the reservoir. Shore angling is rare. Annual angler use, based on boat fishing, is estimated to average 72,608 days. The majority of anglers (42 percent) come from Utah, followed by Colorado (24 percent) and Arizona (23 percent). California and other states make up the remaining 11 percent (Gustaveson, 2000). Currently, the catch rate is 0.3 fish per hour, a number that has declined in recent years due to angling pressure. Approximately one-half of the fish caught are harvested, which results in an average annual harvest of 300,000 fish (NPS, 1996). Fishing catch rates and harvest rates differ at Lake Powell due to changing public attitudes towards catch and release. Most anglers release smallmouth bass and harvest striped bass. In 1997, 86 percent of the smallmouth bass caught were returned, compared to only 28 percent of the 396,000 striped bass caught (Gustaveson, 2000). Most Lake Powell anglers seek a fishing opportunity and would rather catch any fish, compared to a targeted individual species. However, when asked forraor i species In e anglers tend to preference, most anglers prefer to catch black bass or striped bass. t Most17 f the 9, 0 target species they expect to catch most readily. (Gustaveson, 2000). 2 pt. o e r2 .D be on v Novem atiincreasing biocontaminant concentration in Recent studies have indicated a trend of d on oN avaj rchive Ndam. Selenium has been found in plankton and in striped aquatic organisms nearn i the ,a cited 1686 yet bass. Although there have not 4 been any apparent negative impacts on striped bass 14reproduction, selenium can pose a health risk to anglers from consumption. If the No. presence of selenium continues, educating the anglers and performing risk assessment studies may be necessary (NPS, 1996). 3.9.5.2.2 Sport Fishing in Lake Mead Fishing is a favorite activity at Lake Mead. Largemouth bass, striped bass, channel catfish, rainbow trout, bullhead catfish, sunfish, crappie, and bluegill can be found in Lake Mead. Lake Mead is famous for its striped bass, with an occasional catch weighing over 40 pounds, although weights of three to five pounds are more common. Angler survey results from NDOW indicate that since 1984, striped bass have been the species most sought after by anglers by a wide margin (62.7 percent) (NDOW, 2000). Fishing for striped bass or largemouth bass is good throughout the entire lake, but panfish and catfish are more prevalent in the upper Overton Arm. The Nevada Division of Wildlife (NDOW) stocks rainbow trout from late December through the spring months. The razorback sucker, a protected fish species, must be COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-41 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 363 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 returned to the water immediately and carefully, if caught. Fishing is generally better in the fall months of September, October and November. Larger fish are caught by deep water trolling in spring from March through May. To fish from shore, a valid license is required from the state where the fishing occurs. If fishing from a boat or other flotation device, a use stamp from the other state is required. Rainbow trout fishing also requires an additional stamp. Children under 14 are not required to have a license. The NDOW conducts annual creel and angler use surveys of Nevada licensed anglers (resident and non-resident). While Arizona licensed anglers also fish in Lake Mead, it is estimated that roughly 80 percent of the fishing use on the reservoir is represented in the NDOW surveys (Sjöberg, 2000). NDOW’s annual statewide angler questionnaire is mailed out to 10 percent of all Nevada licensed anglers, resident and non-resident. Table 3.9-11 presents data from 10 years of questionnaires. Table 3.9-11 Nevada Division of Wildlife Annual Angler Questionnaire Results for Lake Mead Fish per ior Angler Inter 17 Day he 0 . of t pt10.72 er 29, 2 44,444 476,543 940,608 De 21.16 1.97 . b ion v Novem t 41,012 488,381 jo Na 934,807 n 11.91 22.79 1.91 o va ived Na ch n 47,873 d i 792,883 , ar 1,532,481 16.56 32.01 1.93 cite 16864 4- 558,301 46,460 1 1,314,508 12.02 28.29 2.35 No. Anglers Angler Days Fish Harvest (all species) Days per Angler Fish per Angler 1993 46,649 697,117 1,699,816 14.94 36.44 2.44 1994 45,507 648,928 1,710,412 14.26 37.59 2.64 1995 47,630 574,972 1,590,413 12.07 33.39 2.77 1996 42,715 554,625 1,410,440 12.98 33.02 2.54 1997 43,747 505,892 1,239,840 11.56 28.34 2.45 1998 43,831 612,551 1,568,676 13.98 35.79 2.56 Average 44,987 591,019 1,394,200 13.10 30.88 2.36 Year 1989 1990 1991 1992 Source: NDOW, Statewide Angler Questionnaire Database, 1989 through 1998, cover letter dated 5 October, 2000. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-42 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 364 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 The Arizona Department of Game and Fish estimated the Arizona licensed angler use for Lake Mead (based on Nevada survey results) to be 118,422 days in 1995. Combined with Nevada’s use estimate for the same year, there were 693,394 angler days on Lake Mead in 1995 (83 percent from Nevada, and 17 percent from Arizona). 3.9.5.2.3 Sport Fishing in Lake Mohave This section discusses sport fishing in Lake Mohave, below Hoover Dam. Table 3.9-12 shows the developed access sites and facilities at Lake Mohave. Table 3.9-12 Lake Mohave Developed Recreation Facilities Facilities Willow Beach Cottonwood Cove Katherine • • • Lodging N/A • • Trailer Village (fee) N/A • • Campground N/A • • • • • Ranger Station erior Food Service • • e Int 017 f th Grocery/Gift Shop pt. o • er 29, 2 • . De b ion v Novem Gasoline • a•t on jo N Picnic Area • • Nava archived in ited 6864, N/A Shower (fee) c • 1 . 14Trailer SewageNo Dump • • Marina • • • • • • Boat Sewage Dump • • • Self-service laundry N/A • • • • • N/A • • Propane Service Houseboat Rentals Source: NPS, 1995. indicates presence of improvement • N/A indicates no improvement In Lake Mohave there are largemouth bass, striped bass, channel catfish, rainbow trout, bullhead catfish, sunfish, crappie and bluegill. Because Lake Mohave is within the LMNRA, the same fishing rules and requirements described above for Lake Mead apply to Lake Mohave. NDOW stocks rainbow trout in the lake from late December through the spring months. The USFWS stocks rainbow trout throughout the year, with concentrated stocking October through May. Three protected species, including razorback sucker, Colorado squawfish, and bonytail chub, are the last of the native Colorado River fish and can be found in Lake Mohave. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-43 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 365 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 When caught, these fish must be released. Fishing is open year round, but the best fishing generally occurs in September, October and November. For deep water trolling, March through May is best. Fishing on Lake Mohave can be exceptional. Bass and trout often run three pounds, with some trout weighing as much as 10 or more pounds. Anglers fish for big trout at Willow Beach, while Cottonwood Cove and Katherine Landing offer both bass and trout fishing. Within the last few years, striped bass fishing has become very popular. The NDOW conducts annual creel surveys at Cottonwood Cove and Willow Beach. In 1998, angler use for Lake Mohave was estimated at 155,654 angler days, about the same as in 1997. The 1998 lake-wide harvest was estimated at 414,954 fish. Of the species caught, 80 percent were striped bass and 12 percent were rainbow trout. Other species included largemouth bass, channel catfish, and sunfish. 3.9.5.3 ENVIRONMENTAL CONSEQUENCES 3.9.5.3.1 Sport Fishing in Lake Powell, Lake Mead and Lake Mohave Reduced reservoir surface elevations could affect recreational reservoir fishing by ior decreasing the number of fishing days and angler satisfaction.eThe er Int lower pool 7 th elevations could cause temporary or permanent closure of relocation of01 pt. or er 29, 2 shoreline e b facilities, thus requiring the boat angler to n v. D another launch site, fish from io either travel tom ove at day. on Nnavigational issues, such as the the bank, or possibly forego fishingN Also, jo that Nava arch ved closure of areas of theireservoirs, could iincrease travel times to desired fishing locations n cited 16864, and result in reduced angler satisfaction. Lower pool elevations may make some shoreline fishingo. 14 inaccessible. In addition, as discussed in Section 3.9.3.2, as pool N areas elevations lower, the surface area available for boats and safe boat capacity decreases. The boat angler may need to call ahead for reservoir conditions. Lake Mohave surface elevations will not be affected by any of the alternatives. No direct information on angler success rates or angler satisfaction in relationship to reservoir pool elevations is available. Therefore, potential effects were determined indirectly through consideration of potential effects on sport fishery production and water access for boat and shore anglers. The effects of the alternatives on sports fishery production are discussed in detail in Section 3.7.4. The effects on boating access, including shoreline facilities that provide access to the water for boat angling and navigational constraints on boating, are discussed in Sections 3.9.2 and 3.9.3. As discussed in Section 3.7.4, Sport Fisheries, potential reductions in surface elevations associated with the interim surplus criteria alternatives are not expected to affect sport fishery composition or quantities within the reservoirs. As such, angler success rates at Lake Powell and Lake Mead would not be reduced. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-44 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 366 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.9.6 CHAPTER 3 RECREATIONAL FACILITIES OPERATIONAL COSTS In order to keep reservoir marinas, boat launching, public use beaches and shoreline access operational, facility owners/operators and agencies providing utility connections must respond to fluctuating pool elevations. This section focuses on the operational and capital costs of keeping recreational facilities in operation as reservoir surface elevations change. Potential revenue effects from changes in recreation use are not considered. As discussed above, it is not expected that baseline conditions or interim surplus criteria would result in facility closures, as most facilities can be relocated to maintain operation at lower reservoir elevations. 3.9.6.1 METHODOLOGY Information in the affected environment section was compiled after review of available published and unpublished sources and through personal communication with NPS specialists. Available data do not cover all facilities. Furthermore, the analysis is generally based on professional judgment, extrapolating from limited historical data. However, the analysis provides a useful approximation of the order ofior magnitude of Inter 17 costs to recreational facilities that may be incurred under projections for each of the f the 9, 20 alternatives. pt. o 2 e .D ber vem ion vcosts, projections of the costs associated Nat d Using data associated with facility relocation on No vajo hivthe river system modeling discussed in Section with declines were made Na results of e in using4, arc itedpotential costs use model projections associated with the 50 6 c 3.3. Calculations of -168 percent exceedence 14 . probability elevations for years 2002 through 2016. This No simplified methodology addresses multi-year changes in elevation, and does not consider costs associated with facility adjustments to accommodate monthly fluctuations. 3.9.6.2 AFFECTED ENVIRONMENT The following sections discuss costs associated with relocation of reservoir marinas and boat launching facilities at Lake Powell and Lake Mead. Many of the facilities at Lake Powell and Lake Mead were constructed when the reservoirs were near their maximum pool elevations of 3700 feet msl and 1210 feet msl, respectively. 3.9.6.2.1 Lake Powell The costs of fluctuating pool elevations on Lake Powell marinas and boat-launching facilities were calculated by Combrink and Collins (1992). The study calculated operating costs for one-foot fluctuations (termed “normal adjustments”) and for adjustments when the pool fluctuation exceeds 25 feet (termed “special adjustments”). The normal adjustments are adjustments made within the range of regular operations and are done routinely as water levels change during the year. Special adjustments COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-45 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 367 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 include relocations of anchors and extensions of cables and utilities. The study found that major capital investments would be needed; cost estimates were developed based on a 50-foot decline in pool elevations. Additional data for the Antelope Point Marina has been provided by the Navajo Nation and National Park Service. Construction drawings have been prepared to allow extension of the ramp from 3677 to 3620 feet msl, with a reported capital cost estimate of approximately $500,000 (Bishop, Personal Communication, 2000). This cost has been included in NPS planning for Antelope Point. Table 3.9-13 presents the costs incurred per adjustment in the form that the data was collected. In order to use the data to compare different alternatives, it has been converted into a cost per foot of fluctuation. Data collected in 1989 has been updated to 2000 price levels. Table 3.9-13 Costs Associated with Adjustments to Lake Powell Recreation Facilities Cost per Adjustment 1 Adjustment Cost Category Cost per Foot ior Inter 17 f the$1,721 0 Operating Cost for a Normal Adjustment $1,275 t. $1,721 p o er 29, 2 (based on one-foot fluctuation) De mb n v. o ove Operating Cost for a Special Adjustment Nati $33,460 $45,171 $1,807 on N ajo (fluctuations exceeding 25 feet) av ed in N 4, archiv $2,000,000 Capital Cost for each 50-foot drop $2,700,000 $54,000 cited 1686 4Total Cost per Foot. 1 $57,528 No 1989 Price 2 Level Additional Capital Cost for drop below 3677 4 water surface elevation 2000 Price 3 Level $500,000 1 . Operating costs are the cost of adjusting the existing facilities for fluctuations and consist of labor hours. Capital costs consist of construction of ramp extensions, utility line extensions and relocations. 2 Combrink and Collins (1992). 3 Consumer Price Index-All Urban Consumers. 1989 average is 124.0. March 2000 is 167.8. Adjustment factor: 167.8/124.0 = 1.35 4 Capital cost to extend the toe of the existing Antelope Point Marina from 3677 to 3620 feet msl (Bishop, Personal Communication, 2000). Table 3.9-13 indicates there are costs associated with even minor changes in pool elevations. However, the cost of capital improvements required to extend utilities and access below the range of elevations that can be accommodated by existing infrastructure is much larger than the operating costs incurred within the capacity of the existing infrastructure. It should be noted that many of the Lake Powell shoreline facilities were extended in 1992/93 to accommodate reduced Lake Powell surface elevation down to 3612 feet msl. Due to these extensions, the actual costs of relocating facilities in the event of future COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-46 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 368 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Lake Powell surface elevation declines may be lower than those indicated in the analysis. 3.9.6.2.2 Lake Mead NPS provided information on costs associated with relocation of facilities at Lake Mead. The operating levels range between full pool elevation (1210 feet msl) and 1180 feet msl. When Lake Mead declines to 1180 feet msl, adjustments need to be made to the major facilities. Costs to make these adjustments for each of the major facilities at year 2000 price levels range from $560,000 to $970,000. NPS has also determined that additional incremental drops of 20 feet in elevation will incur additional costs, ranging from $480,000 to $800,000 (Henderson, 2000). Costs associated with fluctuating pool elevations are available for federally-owned facilities at LMNRA from unpublished data assembled by the Resource Management Office, Lake Mead NRA (Henderson, Burke and Vanderford, April 17 and 18, 2000). In addition, Overton Beach Marina (letter dated March 29, 2000) and Lake Mead Resort (letter dated April 11, 2000) provided information to Reclamation indicating the costs associated with fluctuating reservoir elevations. Table 3.9-14 presents these costs. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove N Cost per jo Fluctuation Increment Nava archived in , c ted 1 1686 of Cost toiLMNRA facilities4 surface elevation occurrence below $ 6,011,000 1180 feet.msl o 14 N Table 3.9-14 Costs Incurred to Recreational Facilities from Lake Mead Pool Fluctuations (Year 2000 Price Level) Line No. 1 2 3 5 Cost to Temple Bar Resort from a 10-foot drop 7 4 Cost to Overton Beach Marina Facilities from a fluctuation from 1150 3 feet msl to 1130 feet msl (20 feet) 6 3 Cost to Overton Beach Marina facilities from a fluctuation from 1212 3 feet msl to 1150 feet msl (62 feet) 5 2 Cost to Lake Mead Resort Marina from a 20-foot drop in elevation 4 1 Cost to LMNRA facilities at 1160 feet msl and at each additional 1 20-foot drop Cost to Echo Bay Resort from a 20-foot drop from 1213 feet msl to 5 1193 feet msl $ 5,080,000 2 4 $ 91,400 $ 60,000 $ 425,000 $ 12,500 $ 38,400 Unpublished data from Lake Mead NRA. Letter dated April 11, 2000, from Lake Mead Resort to Reclamation. The letter quantifies cost for a drop from current pool elevations. It also notes that a drop below 1150 would, in the NPS’s judgement, require abandonment of the basin within which the resort is located. Letter dated March 29, 2000, from Overton Beach Marina to Reclamation. Letter dated March 27, 2000, from Temple Bar Resort. Midpoint of range ($10,000 to $15,000) is used. Letter further notes that a drop below 1125 feet msl would require a complete relocation of the marina, including buildings located on land. Letter dated March 16, 2000, from Echo Bay Resort to Reclamation. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-47 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 369 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.9.6.3 ENVIRONMENTAL CONSEQUENCES 3.9.6.3.1 Lake Powell As discussed in the methodology section, an estimate can be made of the cost impacts of the alternatives on Lake Powell recreational facilities under some basic conditions. Estimates in this section are for aggregate relocation costs associated with all identified Lake Powell shoreline facilities. Table 3.9-15 shows estimated incremental costs that would be incurred from Lake Powell surface elevation decreases associated with the median elevation projections for baseline conditions and each alternative from 2002 through 2016 (Figure 3.9-1 presents these elevations graphically). These impacts are based on a cost of $57,528 per foot change in elevation, developed based on the information shown in Table 3.9-12. Table 3.9-15 Costs Associated with Potential Relocation of Lake Powell Recreational Facilities 1 Under Alternatives Compared to Baseline Conditions (Year 2000 Price Level) or iIncremental Cost Inter during 15-Year 017 3 f the pt. o er 29, 2 Period . De b Baseline Conditions 3665 n 0 --------io v Novem at ajo N3664 ed on Basin States Alternative 1 $ 747,864 iv Nav d in 64, arch $ 0 Flood Control Alternative 3665 0 cite 168 4Six States Alternative 1 3664 1 $ 747,864 No. Median Elevation in Year 2016 2 (feet msl) Elevation Below Baseline Conditions (feet) California Alternative 3660 5 $1,208,088 Shortage Protection Alternative 3659 6 $1,438,200 Alternative 1 2 3 Assumes pool elevation decreases constantly over time, following 50% probability of exceedence elevation. Based on 50 percent probability of exceedence elevation projected from modeling on July 31 of each year. Table 3.9-13. $57,528 per foot for each facility. No incremental cost is included for extending the ramp at the Antelope Point Marina.. By 2050, the median elevation of all alternatives is within a two-foot range (3662.5 to 3664.6) and the difference in costs is small. 3.9.6.3.2 Lake Mead As discussed in the methodology section, an estimate can be made of the cost impact of the alternatives on Lake Mead recreational facilities using certain assumptions. Table 3.9-16 shows estimated incremental costs that would be incurred from Lake Mead surface elevation decreases associated with the median elevation projections for COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-48 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 370 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 each alternative as compared to baseline conditions from 2002 through 2016 (Figure 3.9-4 presents the median elevations graphically). Table 3.9-16 Costs Associated with Potential Relocation of Lake Mead Recreational Facilities 1 Under Alternatives Compared to Baseline Conditions Elevation in Year 2016 2 (feet msl) Elevation Below Baseline Conditions Incremental Cost during 15-Year Period Baseline Conditions 1162 N/A NA Basin States Alternative 1143 19 $ 5,243,900 Flood Control Alternative 1162 0 0 Six States Alternative 1146 16 $ 5,243,900 California Alternative 1131 31 $ 10,348,900 4 Shortage Protection Alternative 1130 32 $ 10,773,900 5 Alternative 3 3 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited elevation4, all alternatives is the same (1110.6 feet msl), and By 2050, the median -1686 under 4 no differencesNo. 1 would occur. in cost 1 2 3 4 5 Assumes pool elevation decreases constantly over time, following 50% probability of exceedence elevation. Based on 50 percent probability of exceedence elevation on December 31 of each year projected from river system modeling. Lines 2, 3, 4 and 6 from Table 3.9-14. Two times Line 2, one times Line 3 and 4, and three times Line 6 from Table 3.9-14. Two times Line 2, one times Lines 3, 4 and 5, and three times Line 6 from Table 3.9-14. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.9-49 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 371 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.10 ENERGY RESOURCES 3.10.1 INTRODUCTION The analyses in this section consider two specific issues associated with energy resources. The first issue considered is potential changes in hydropower production from Hoover Dam and Glen Canyon Dam; the second is potential increases in energy requirements of the Southern Nevada Water System (SNWS) Lake Mead intake, Navajo Generating Station cooling water intake in Lake Powell and the City of Page potable water intake in Lake Powell. 3.10.2 HYDROPOWER This section discusses potential changes in power production that could occur as a result of the interim surplus criteria under consideration. The analysis focuses on changes in production from Glen Canyon Dam and Hoover Dam for each alternative compared to baseline conditions. 3.10.2.1 METHODOLOGY ior ter In order to determine the effects of the interim surplus criteria alternatives,7 he In detail1 the of t information produced from the river system modeling .described 29, 20 in Section 3.3 in ept Canyon and Hoover . D Glenember has been used. This model simulates operation of nv Natio d interimv powerplants under baseline conditions and theon No surplus criteria alternatives. The vajo output quantities of then Na that arehive i model 4, arc important in determining the effects of the d alternatives on cite generation are: power 1686 No. 14- • Annual average Lake Powell Elevation; • Annual average Glen Canyon Powerplant Energy Production; • Annual average Lake Mead Elevation; • Annual average Hoover Powerplant Energy Production; • Annual average Lake Mohave Elevation (constant at an elevation of 647 feet msl throughout the period of analysis). These quantities, derived from the model runs, are shown in Tables 1, 2, 5 and 7 in Attachment P. In addition, powerplant capability curves for Glen Canyon and Hoover powerplants showing powerplant capacity as a function of lake elevation (or net effective head) are required to determine how the capacity varies for each alternative throughout the study period. Powerplant capability curves used for the analysis are presented in Tables 3 and 4 in Attachment P. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 372 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3 of Attachment P uses discharge multipliers to determine the maximum operable capacity of the Glen Canyon Powerplant. The maximum water release of 25,000 cfs (restricted except during power system emergencies) is divided by the discharge multiplier to calculate the capacity. Table 4, for Hoover Powerplant, uses the theoretical turbine curve data for heads from 560 feet to 590 feet. Below 560 feet of head, a ratio of 2062/2074 has been applied to the turbine curve data to reflect recent downratings of units A3, A4, and A8 as reported in a letter dated July 2000, from the Area Manager of Reclamation to Western. As used herein, powerplant capacity refers to the load that a generator or facility can achieve at a given moment. Energy is a measure of electric capacity generated over time. Comparing the projected amount of powerplant generating capacity and energy production available under the various alternatives with baseline projections produces a probabilistic measure of the effects of the alternatives on power production if the assumptions contained in the forecasts covering water supply materialize. The methodology for determination of the effects of the alternatives is to compare the change in capacity and energy production, on an annual basis, between baseline conditions and each alternative. Annual average generating capacity and energy available from Glen Canyon and Hoover powerplants was determinedior the using Inter discussed in reservoir elevation and energy output quantities from system modeling 017 f the pt. o of 29, 2 Section 3.3, and the powerplant capability curves.eModelinger energy production is b v. D based on aggregate turbine production curves. Annual em ation on Nov average capacity and energy jo N v alternatives are shown in Tables 5 and 7 in production for baseline conditions and theed Navaenergy production is also shown in Figures 3.10-1 and chi i Attachment P. Annualn 4 r ited average , a 6 c 3.10-2. Comparisons4-168annual average energy production associated with each 1 of the . annual average energy production of baseline conditions are shown alternative and the No in Tables 6 and 8 in Attachment P. 3.10.2.2 AFFECTED ENVIRONMENT The energy resources that could be affected by changes in Colorado River operation are Glen Canyon Powerplant and Hoover Powerplant electrical power output. The reservoirs behind these facilities are operated to store Colorado River water for delivery in the Lower Colorado River Basin below Glen Canyon Dam, and water to meet delivery obligations to Arizona, California, Nevada and Mexico downstream of Hoover Dam. 3.10.2.2.1 Factors of Power Production In general, the two factors of a hydroelectric system, excluding machinery capability, that are directly related to power production are the net effective head on the generating units, and the quantity of water flowing through the turbines. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 373 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 The net effective head is the difference between the water surface elevations of the forebay behind a dam and in the tailwater below the dam. The head determines the maximum capacity, measured in MW, that is available from the powerplant. The nameplate capacity of Glen Canyon Powerplant is 1296 MW. However, the maximum operating capacity of Glen Canyon Powerplant generators is approximately 1200 MW due to turbine restrictions (Western, 1998). Because the maximum allowable water release has been limited to 25,000 cfs, the maximum operable capacity for Glen Canyon is limited to 1048 MW, except during a power system emergency. The maximum operating capacity of Hoover Powerplant is 2074 MW. The net effective head on the powerplant is influenced by the reservoir surface elevations and operating strategies for both the upstream and downstream reservoirs. The quantity of water flowing through the turbines (water releases) determines the amount of energy produced, measured in gigawatt-hours (GWh). The net energy generated during fiscal year 1998 from Glen Canyon Powerplant and Hoover Powerplant was 6626 GWh and 5768 GWh, respectively (Western, 1998 and Reclamation, 2000). The turbines at a powerplant are designed to produce maximum efficiency at a design head. At design head, the plant can produce the maximum capacity and r most te io the Innetreffective head on energy per acre-foot of water passing through the turbine.f Ase th the 017 pt. o er 29, 2 the powerplant is reduced from design head because of reduced forebay (upstream . De is reduced, the electrical capacity of b reservoir) elevation, the power outputation v of the turbine ovem N jo N ved o and the generator attached to the turbine is reduced,n the efficiency of the turbine is i Nava aas net effective head decreases until, below the in reduced. This reduction continues rch ited 6864, c minimum elevation for-power generation, the turbines cannot be operated safely and 1 1 downstream water deliveries. Minimum power elevation o.for 4 must be bypassed N generally occurs at a point where cavitation within the turbine causes extremely rough operation, air may become entrained in the water, and/or vortices may appear in the forebay. 3.10.2.2.2 Power Marketing and Customers The effects of any surplus or deficit in power generation are incurred by the customers to whom the power from Glen Canyon and Hoover powerplants is allocated. The contracts for power from Glen Canyon Dam terminate in 2025. The contracts for power from Hoover Dam terminate in 2017. The identity of the recipients of power from these resources is not known for about two-thirds of the period of analysis for Hoover Dam and about one-half of the period of analysis for Glen Canyon Dam. Therefore, an analysis of the effects of the alternatives compared with those of baseline conditions will consider the general effects in the overall areas served by the resources, although a future group of power customers would be impacted similarly to current customers. The states that would be affected by changes in energy and capacity at Glen Canyon and Hoover powerplants are Arizona, California, Nevada, Utah, Wyoming, New COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 374 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Mexico and Colorado. These states make up the Rocky Mountain, Arizona-New Mexico-Southern Nevada, and California-Mexico areas of the Western Systems Coordinating Council (WSCC). Electrical energy produced in each of these areas is derived from a variety of sources. The power from Glen Canyon Powerplant and Hoover Powerplant contributes a small, but significant portion of the energy produced in these areas. The total generation capability of the areas as of January 1, 1999, is 86,348 MW. The generation capability of each WSCC area is: • Rocky Mountain 10,584 MW • Arizona-New Mexico-Southern Nevada 22,272 MW • California-Mexico 53,492 MW Glen Canyon and Hoover powerplants contribute approximately 3.6 percent of the total generating capability of these three areas of WSCC (WSCC, 1999). The maximum capacity available from Glen Canyon Powerplant at elevation 3700 feet msl has been restricted to approximately 1200 MW. However, as stated above, the maximum operable capacity at Glen Canyon Powerplant is limited to 1048 MW due to water release restrictions, except during power system emergencies. Therefore, for the or nte i 7 IGlenrCanyon purposes of this analysis, the operable capacities of Hooverthe 01 f and powerplants are 2074 MW and 1048 MW, respectively,o a total9, 2 pt. for r 2 of 3122 MW. e D v. mbe ation on Nove 3.10.2.3 ENVIRONMENTAL CONSEQUENCES jo N Nava archived in cited 16864, The environmental consequences of a change in river operations that impacts power 14production can be .measured by the increase or decrease in capacity and energy available No from the powerplants. The power production under the alternatives is compared with power production under baseline conditions to determine the incremental effects of each alternative, using annual average modeled reservoir levels and downstream releases. Reductions in capacity, energy, and generation ancillary services from Glen Canyon and Hoover powerplants under baseline conditions would ultimately need to be replaced by either types of generation. Additional incremental reductions under each alternative would also ultimately need to be replaced. The replacement of Glen Canyon and Hoover powerplant generation could be accomplished through a number of different strategies. If capacity loss can be expected for long periods of time, construction of new generation would likely occur. If capacity loss is intermittent throughout the period of analysis, purchases from the short-term market would be expected. If energy loss can be expected for a long period of time, either construction of new generation or operation of higher-cost generation for longer periods of time during the day would be expected. If energy loss is intermittent throughout the period of analysis, replacement from the short-term market would be anticipated. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 375 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.10.2.3.1 Baseline Conditions 3.10.2.3.1.1 Glen Canyon Dam The annual average capacity and energy production at Glen Canyon Dam under baseline projections are shown in Table 5 in Attachment P; the annual average energy production is shown in Figure 3.10-1. The powerplant capacity begins at 1020 MW in 2002 and is reduced to 960 MW in 2016 because of reductions in lake elevation. Subsequently, the capacity increases to 990 MW in 2041, then decreases to 975 MW in 2050. From 2002 through 2016, the greatest annual decrease in capacity is 13 MW between 2012 and 2013. The annual reduction throughout the early years is from two to six MW, representing less than a one percent decline in capacity from the powerplant per year. The output varies cyclically between 2017 and 2050, with annual increases or decreases in capacity of two to six MW. Under baseline conditions, the energy available from Glen Canyon Dam averages 4532 GWh from 2002 through 2016, and 4086 GWh through the rest of the period of analysis. Energy production increases the first year of the study. Thereafter, annual reductions in energy production are generally less than 50 GWh per year through 2016. Annual reductions in energy from 2017 through 2050 are generally less r riothan 40 GWh. Inte f the 9, 2017 3.10.2.3.1.2 Hoover Dam pt. o . De ember 2 nv Natio d Hooverv The annual capacity and energy jproduction at on No Powerplant under baseline va o e conditions are shown in Table 7 of Attachment P; the annual average energy production in Na 4, archiv d cite 16 The is shown in Figure 3.10-2. 86 powerplant capacity begins at 2062 MW in 2002 and is reduced to 2033 o. 14 2016 because of reductions in lake elevation. Capacity N MW in decreases to 1865 MW in the year 2050. From 2002 through 2016, the greatest annual decrease in capacity is nine MW. This reduction represents less than a one percent per year decline in capacity from the powerplant through 2016. From 2017 through the remainder of the period of analysis, the annual capacity reductions are generally less than 10 MW. The energy available from Hoover Powerplant averages 4685 GWh from 2002 through 2016, and 3903 GWh through the rest of the period of analysis. Energy production increases during the first three years of the period of analysis, with annual reductions from 2004 through 2016 of generally less than 50 GWh. Annual reductions in energy from 2017 through 2050 are predominantly less than 60 GWh. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-5 3500 2000 3750 4000 4250 4500 4750 5000 5250 5500 Figure 3.10-1 Glen Canyon Powerplant Annual Average Energy Production 2005 2010 2015 2020 3.10-6 Year 2025 2030 2035 2040 2045 Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Energy Production (GWh) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 376 of 1200 3000 2000 3250 3500 3750 4000 4250 4500 4750 5000 5250 5500 Figure 3.10-2 Hoover Powerplant Annual Average Energy Production 2005 2010 2015 2020 3.10-7 Year 2025 2030 2035 2040 2045 Shortage Protection Alternative California Alternative Six States Alternative Flood Control Alternative Basin States Alternative Baseline Conditions ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS Energy Production (GWh) AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 2050 CHAPTER 3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 377 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 378 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.10.2.3.1.3 Combined Capacity and Energy Reduction Under Baseline Conditions The combined capacity reduction from Glen Canyon and Hoover powerplants through 2016 is 89 MW under baseline conditions. The combined energy production in 2016 is 403 GWh less than year 2002 energy production. In 2050, the capacity reduction is 242 MW less than 2002 levels, and the energy available is reduced 1807 GWh from year 2002 production. Under baseline conditions, power customers can expect a reduction in production from present levels in the future. Because of the gradual withdrawal over time, the deficit is expected to be replaced by short-term purchases made by either the power customers or Western, at the power customer’s option, in accordance with contract terms. 3.10.2.3.2 Basin States Alternative 3.10.2.3.2.1 Glen Canyon Dam The average capacity available from Glen Canyon Powerplant under the Basin States Alternative is shown in Table 5 of Attachment P. The powerplant capacity begins at 1014 MW in 2002 and is reduced to 960 MW in 2016. The capacity varies two to four MW each year until 2050, at which time powerplant capacity is at 975 or ri MW. The average annual capacity available through the period of analysisInt987 MW. is e 7 he of t , 201 ept. earlyer 29through 2016, and The annual energy available averages 4527 GWh in theemb years v. D ation on Novenergy production in 2050 is 4209 GWh throughout the period of analysis. Annual jo N Nava archived 3875 GWh. in cited 16864, 1 3.10.2.3.2.2 Hoover 4No. Dam The average capacity available from Hoover Powerplant is shown in Table 7 of Attachment P. The powerplant capacity begins at 2061 MW in 2002 and is reduced to 1971 MW in 2016. The capacity either increases or decreases in consecutive years by up to 44 MW, with the capacity in 2050 being 1865 MW. The average capacity available throughout the period of analysis is 1935 MW. The average annual energy available is 4701 GWh through 2016, and 4087 GWh throughout the period of analysis. Annual energy production in 2050 is 3496 GWh. 3.10.2.3.3 Flood Control Alternative 3.10.2.3.3.1 Glen Canyon Dam The average capacity and energy available from Glen Canyon Powerplant under the Flood Control Alternative are shown in Table 5 of Attachment P. The powerplant capacity begins at 1020 MW in 2002 and is reduced to 962 MW in 2016. The decline continues to 975 MW in the year 2050. From 2002 through 2016, the greatest annual decrease in capacity is 12 MW. This reduction represents less than a one percent COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 379 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 average decline in powerplant capacity per year through 2016. The capacity either increases or decreases in consecutive years through the remainder of the period of analysis. Capacity changes from the period 2016 through 2050 are predominantly in the two to six MW range each year, either increasing or decreasing. Annual energy production from Glen Canyon averages 4532 GWh in the early years through 2016 and averages 4223 GWh throughout the period of analysis. Annual energy production in 2050 is 3875 GWh. 3.10.2.3.3.2 Hoover Dam The annual capacity and energy available from Hoover Powerplant under the Flood Control Alternative are shown in Table 7 of Attachment P. The powerplant capacity begins at 2062 MW in 2002 and is reduced to 2033 MW in 2016. Powerplant capacity continues on a declining trend, until the capacity reaches 1865 MW in 2050. The greatest declines in the period from 2002 through 2016 are five and 13 MW, with the annual decline in capacity being predominantly one to two MW. Under the Flood Control Alternative, the annual energy available from Hoover Powerplant averages 4686 GWh during the period 2002 through 2016.oThe average for ri r the period from 2017 through 2050 is 3908 GWh. The average Inte entire study for the f the 9, 2017 period is 4146 GWh. pt. o 2 e .D ber ion v Novem 3.10.2.3.4 Six States Alternative Nat on jo Nava archived in 3.10.2.3.4.1 Glened Dam cit Canyon864, 4-16 1 No. The capacity available from Glen Canyon Powerplant under the Six States Alternative begins at 1014 MW in 2002 and decreases to 960 MW in 2016. The capacity then follows a generally increasing trend through 2043, after which annual reductions lead to a capacity of 975 MW in 2050. The capacity available averages 980 MW throughout the period of analysis. Annual changes of between two and five MW are predominant in the Six States Alternative. The annual energy production averages 4527 GWh through 2016, and 4211 GWh throughout the period of analysis. Annual energy reductions throughout the period of analysis are predominantly less than 50 GWh. 3.10.2.3.4.2 Hoover Dam The capacity available from Hoover Powerplant under the Six States Alternative begins at 2061 MW in 2002 and decreases to 2005 MW in 2016. The capacity then follows a decreasing trend until the output reaches 1865 MW in 2050. The predominant annual capacity reductions throughout the study period are less than 10 MW. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 380 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 The average annual energy production is 4698 GWh through 2016. The average annual energy production throughout the period of analysis is 4091 GWh. Annual energy production reductions in successive years are predominantly less than 50 GWh. 3.10.2.3.5 California Alternative 3.10.2.3.5.1 Glen Canyon Dam The capacity available from Glen Canyon Powerplant under the California Alternative begins at 1007 MW in year 2002, and is reduced to 958 MW in 2016. The capacity follows a generally increasing trend from 2016 through the end of the period of analysis. In 2050, the capacity is 975 MW. Annual changes in plant capacity are generally between two and five megawatts. Energy production at Glen Canyon averages 4516 GWh through 2016, and 4193 GWh throughout the entire period of analysis. Annual changes in energy production are generally less than 30 GWh. 3.10.2.3.5.2 Hoover Dam r The capacity available from Hoover Powerplant under the CaliforniarAlternative begins te io he In 2017 follows a at 2061 MW in year 2002, and is reduced to 1907 MW inf2016. The capacity o t 29, ept.of the period of analysis. In generally downward trend from 2016 through . D end mber the nv e 2050, the capacity of Hoover is 1867 atio Annual ov N MW. d on Nchanges in plant capacity are ajo v generally less than 10 imegawatts. rchive n Na a cited 16864, Annual energy production at Hoover averages 4709 GWh through 2016, and 4016 GWh 14No. of analysis. Annual changes in energy production are throughout the period predominantly less than 20 GWh. 3.10.2.3.6 Shortage Protection Alternative 3.10.2.3.6.1 Glen Canyon Dam The capacity available from Glen Canyon Powerplant under the Shortage Protection Alternative begins at 1009 MW in 2002 and is reduced to 958 MW in the year 2016. The capacity generally increases to 988 MW in the early 2040s, then is reduced to 975 MW in the year 2050. Annual capacity variations are generally from two to six megawatts. Energy production averages 4518 GWh through 2016, and 4193 GWh throughout the entire study period. Annual energy production variations are generally less than 30 GWh. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 381 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.10.2.3.6.2 Hoover Dam The capacity available from Hoover Powerplant under the Shortage Protection Alternative begins at 2061 MW in 2002 and is reduced to 1904 MW in 2016. The capacity follows a generally decreasing trend from 2016 through 2050, when the capacity reaches 1865 MW. Annual capacity reductions are predominantly in the two to five megawatt range. Annual energy production averages 4733 GWh from the beginning of the period of analysis to 2016, and 4047 GWh throughout the entire period of analysis. Annual variation throughout the period of analysis is generally less than 100 GWh. 3.10.2.4 COMPARISON OF ALTERNATIVES As discussed above, the amounts of capacity and energy available as a result of each alternative operating strategy vary on an annual basis. The important measurement of the effects of each alternative is their comparison with the baseline conditions. As indicated, the resources available from Glen Canyon and Hoover powerplants can be expected to be reduced over time, due primarily to increased depletions in the Upper Basin states. This effect is included in model runs for baseline conditions. ior Inter hecapacity017 energy of t Table 3.10-1 summarizes the differences between hydropower 29, 2 and ept. ber Values under the .D generation under each alternative and under baseline conditions. m ion v greater than atslightly n Nove under baseline conditions. N Flood Control Alternative are typically ajo do Values under the Californiaav Shortage e in N and , archiv Protection Alternatives are the furthest from cited 1 values baseline conditions, while6864 under the Six States and Basin States alternatives are 14closer to baseline conditions. No. The capacity and energy differences (reductions) between each alternative and baseline conditions would be replaced by power available from the market. The greatest singleyear difference in energy generation at Glen Canyon Powerplant under any of the alternatives as compared to baseline conditions is 102 GWh, under the California and Shortage Protection Alternatives (see Table 6 of Attachment P) or about 2.5 percent of the modeled average annual generation of Glen Canyon. The effects of interim surplus alternatives are greater at Hoover Powerplant. The greatest single-year difference in annual energy generation under any of the alternatives as compared to baseline conditions is 328 GWh under the California Alternative (see Table 8 of Attachment P), or about eight percent of the modeled average annual energy generation. The average annual generation during the period of analysis under the Preferred (Basin States) Alternative is 0.8 percent (0.3 percent at Glen Canyon and 1.3 percent at Hoover) less than under baseline conditions. The quantities of capacity needed to replace reductions, while not significant when compared to the total capacity installed in the three WSCC regions, may be significant to the entity losing the capacity. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 382 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.10-1 1 Hydropower Capacity and Energy – Comparison of Alternatives to Baseline Conditions 2 (Difference between baseline conditions and each alternative ) Alternative 2002 – 2016 2017 – 2050 Average Annual Average Annual Capacity Energy Capacity Energy (MW) (GWh) (MW) (GWh) 2002 – 2050 Average Annual Capacity Energy (MW) (GWh) Glen Canyon Powerplant Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative -10 0 -10 -21 -21 -5 0 -5 -16 -14 -1 0 -1 -1 -1 -16 1 -15 -35 -36 -4 0 -4 -8 -7 -13 1 -12 -30 -29 Hoover Powerplant Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative -14 1 -11 -47 -45 15 0 13 24 20 -14 1 -12 -23 -20 -87 5 -80 -193 -147 -14 1 -12 -30 -28 -56 3 -51 -127 -96 ior Inter 17 e of th -103 , 20 -18 -24 10 ept. -15 r 29 D 1 n v. 0 1 b 1 m e 6 e Natio d on Nov-13 -21 8 -95 -16 vajo -68 e 8 -24 -228 -38 in Na 4, archiv ited 686 -66 6 -21 -183 -35 c 4-1 1 No. Total Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 1 Appendix P, Tables 8 and 10 compare each alternative to baseline conditions. 2 -69 4 -63 -157 -125 Positive (negative) value indicates that cost is higher (lower) under the alternative. At Glen Canyon, the greatest single-year difference in capacity compared to baseline conditions is 36 MW under the Shortage Protection Alternative (see Table 6 of Attachment P). This amount represents a decrease of 3.5 percent from baseline conditions and approximately 0.3 percent of the installed capacity in the Rocky Mountain Area. At Hoover, the greatest single-year difference in capacity compared to baseline conditions is 137 MW under the California Alternative (see Table 8 of Attachment P). This amount represents a decrease of 6.7 percent from baseline conditions and about 0.2 percent of the installed capacity in the three-state marketing area for Hoover. Additional water releases resulting from four of the five alternatives (all but the Flood Control Alternative) under consideration will increase the energy available from the powerplants during the first two to seven years of the interim period. This can be expected to reduce energy purchases by the customers from alternate, higher priced COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 383 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 resources. Future reductions in power production can be expected to necessitate increased purchases of capacity to meet peak loads and reserves. Purchases of replacement power by power customers would result in changes in costs and increased exposure to market volatility. 3.10.3 SOUTHERN NEVADA WATER SYSTEM LAKE MEAD INTAKE ENERGY REQUIREMENTS This section discusses potential increases in operating costs of the SNWS Lake Mead intakes that could occur as a result of implementation of the interim surplus criteria alternatives. Increased pumping costs could occur if the alternatives cause lower Lake Mead water surface elevations than baseline conditions. 3.10.3.1 METHODOLOGY River system modeling, described in detail in Section 3.3, provided the average monthly elevation of Lake Mead for each year during the study period for baseline conditions and each of the alternatives. These elevations are shown in Table 2 of Attachment P. Increases or decreases in net effective pumping head correspond to decreases or increases in Lake Mead Surface elevations. The net effective pumping head differences ior Inter 1 2 between the baseline and the alternative strategies are also shown in Table7 of f the Attachment P. Using an estimate prepared by SNWA.(Johnson, 29, 20 incremental pt o er 2000) for e b pumping costs of $28,000 per year associated . D each foot of increased pumping ion v with ovem at is shown in Table 2 of Attachment P. N head, the increased cost of each jalternative d on aoN v e n Na , ar iv d iNVIRONMENT ch cite 3.10.3.2 AFFECTED E 16864 14No. through the SNWA, diverts most of its allocation of Colorado The State of Nevada, River water from Lake Mead through the SNWS into the Las Vegas Valley and adjacent areas. The power-consuming features of this system are the pumping plants from Lake Mead to the water treatment facility. The energy required to provide this lift is a function of the net difference in elevation between the Lake Mead water surface and the water treatment facility. Any increase in the net effective pumping head would increase the amount of energy required to pump each acre-foot of water from Lake Mead. The net effective pumping head will increase as the Lake Mead elevation falls. Water users in Clark County, Nevada and possibly others would absorb increased costs associated with water supply. 3.10.3.3 ENVIRONMENTAL CONSEQUENCES The difference in net effective pumping head between each alternative and baseline projections is used to determine the effects of each alternative on pumping cost. The following analysis uses the estimate of $28,000 per year per foot increase in net effective pumping head furnished in the aforementioned letter. Baseline pumping costs were not calculated. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 384 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.10.3.3.1 Baseline Conditions and Alternatives Under baseline conditions, the average elevation of Lake Mead declines from 2002 through 2050. These results indicate that under baseline conditions and each of the alternatives, SNWA can expect pumping costs to increase due to the increase in net effective pumping head. Table 3.10-2 summarizes potential differences between pumping costs under the alternatives and baseline conditions. Table 3.10-2 Southern Nevada Water System Lake Mead Intake Energy Requirements 1 Average Annual Power Cost – Comparison of Alternatives to Baseline Conditions (Differences between baseline conditions and each alternative) Alternative Basin States Alternative Flood Control Alternative Six States Alternative California Alternative Shortage Protection Alternative 1 2 2002-2016 $ 229,395 $ -32,685 $ 214,779 $ 544,843 $ 532,635 2017 - 2050 $ 94,352 $ -21,025 $ 88,027 $ 205,652 $ 170,314 2002 - 2050 $ 135,691 $ -24,594 $ 126,829 $ 309,486 $ 281,229 $28,000/per year per foot increase in net effective pumping head at year 2000 price level Positive (negative) value indicates that cost is higher (lower) under the alternative. ior Inter results in The Flood Control Alternative, when compared to baselinetconditions, 017 f he 9, 2 pt. ointo er system. The Basin reduced costs for SNWA to pump Colorado Rivere D water m its 2 n v. pumpingb increases of about States and Six States alternatives resulttin averageNove cost a io ajo N ived on The California Alternative and the $130,000 per year over the av period of analysis. N entire h Shortage Protectiond in Alternative , arc in average pumping cost increases of about cite the 864 result of analysis. $300,000 per year over-16 entire period 14 No. 3.10.4 INTAKE ENERGY REQUIREMENTS AT LAKE POWELL This section discusses potential changes in pumping costs for two entities that pump water from Lake Powell: the Navajo Generating Station which obtains cooling water from Lake Powell, and the City of Page which obtains municipal water from Lake Powell. Incremental differences in pumping costs are associated with differences in modeled average Lake Powell surface elevations between baseline conditions and alternatives. 3.10.4.1 METHODOLOGY River system modeling, described in detail in Section 3.3, provided the average elevation of Lake Powell for each year during the study period for baseline conditions and for each of the alternatives. Increases or decreases in net effective pumping head correspond with decreases or increases in Lake Powell surface elevations. Lake Powell elevations and the net effective pumping head differences between baseline conditions and the alternatives are shown in Table 1 of Attachment P. Estimates of the differences COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-14 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 385 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 in pumping costs were calculated using these changes in pumping head, as well as estimates of annual water use, unit energy costs and pump efficiency. The formula for calculating energy requirements (E) as a function of pump lift (H) is: E = V * 1.024 * (H/e) Where V is the volume of water pumped and e is pump efficiency. 3.10.4.2 AFFECTED ENVIRONMENT The Navajo Generating Station is a 2250 MW, coal-powered plant jointly owned by Reclamation, Salt River Project, Los Angeles Department of Water and Power, Arizona Public Service Company, Nevada Power and Tucson Electric Power. The Salt River Project (SRP) operates the plant. The SRP projects that water use will be approximately 29,000 afy in the future. Power for the intake pumps is obtained from auxiliary power units at the Generating Station at a cost of $0.0104 per kWh. Pump efficiency is estimated by SRP at 75 percent. (Weeks, 2000) The City of Page provides municipal water to approximately 7800 residents from Lake erior produced at Powell. The intake pump station is operated by Reclamation e Int power 7 using 01 f th dominated the Glen Canyon Power Plant. Municipal water usept. Page is r 29, 2 by residential in o e e v. D A negligible amount of treated use with substantial residential landscape irrigation. ovemb ation for use at the dam. Presuming 275 gallons N water is delivered by the cityvajo N to Reclamation on v Na wouldhbe ed per day per resident, annual use , arc i approximately 2400 afy. An overall in ited for864pump station was used as a reasonable estimate. A cost c efficiency of 75 percent 16 the 4of $0.03 per kWh . 1 estimated as the cost of the electricity. No was 3.10.4.3 ENVIRONMENTAL CONSEQUENCES The difference in net effective pumping head between each alternative and baseline projections was used to determine the effects of each alternative on pumping cost. Baseline pumping costs were not calculated. Under baseline projections, the average elevation of Lake Powell declines from elevation 3685 feet msl in year 2002 to elevation 3661 feet msl in year 2050 (Appendix P, Table 1). Table 3.10-3 compares the annual power costs of each alternative to baseline conditions. As Lake Powell water elevations are within hundredths of a foot for baseline conditions and for the Flood Control Alternative, no change in pumping costs would occur. For all other alternatives, Lake Powell water elevations average less than under baseline conditions. Average pumping costs would be higher for both the Navajo Generating Station (average increase of $808 per year over the period of analysis for the Basin States Alternative) and for the Reclamation-operated raw water intake serving the City COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-15 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 386 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 of Page. (Average increase of $193 per year over the period of analysis for the Basin States Alternative). Table 3.10-3 Intake Energy Requirements at Lake Powell Average Annual Power Cost – Comparison of Alternatives to Baseline Conditions (Difference between baseline conditions and each alternative) Alternative 2002–2016 Navajo Generating Station Intake Energy Requirements Basin States $ 2,216 Flood Control 0 Six States 2,129 California 4,651 Shortage Protection 4,660 2 City of Page Municipal Water Supply Basin States $ 529 Flood Control 0 Six States 508 California 1,110 Shortage Protection 1,112 1 2 2017–2050 $ 186 0 172 303 312 $ 808 0 771 1,634 1,643 $ $ 193 0 184 390 392 44 0 41 72 74 ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. E(kWh) = 1.024 * 29,000 * (H/0.75). Cost = E(kWh) * $ 0.0104 E(kWh) = 1.024 * 2,400 * (H/0.75). Cost = E(kWh) * $ 0.03 Estimates are annual averages for the indicated time periods. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.10-16 2002–2050 1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 387 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.11 AIR QUALITY 3.11.1 INTRODUCTION Adoption of interim surplus criteria would not involve new construction or physical activities that would result in air emissions within the area of potential effect considered in this FEIS. Air quality effects discussed in this FEIS are limited to changes in fugitive dust emissions that could result from changes in exposed reservoir shoreline as a result of potential changes in Lake Mead and Lake Powell water surface elevations. 3.11.2 FUGITIVE DUST FROM EXPOSED SHORELINE This air quality analysis provides an overview of ambient air quality in the project area, as well as a qualitative review of the potential changes in fugitive dust emissions associated with the project alternatives when compared to fugitive dust emissions that may occur under baseline projections. 3.11.2.1 METHODOLOGY Variations in fugitive dust emissions can result from changes in the arearof exposed io shoreline due to changes in water operating levels. The amountsnter he I of fugitive dust and 17 generated per acre of exposed shoreline vary dependingof t soil 9, 20 pt. uponer 2 characteristics e other factors such as moisture content, wind v. D direction, and local topography. In mb ion speed, ovemission potential from exposed at fugitive dust e N developing a methodology for ajo N reviewing d on v Lake Mead, the following assumptions were made: shoreline around Lakein Na andarchive Powell cited 16864, 14• The incremental changes in exposed shoreline area are related to incremental No. changes in water surface elevation as indicated by existing reservoir area elevation data. However, the true area of exposed shoreline terrain is also affected by the slope of the terrain along the shoreline. To account for sloping terrain, an average shoreline slope of 30 degrees and 45 degrees from horizontal was assumed for Lake Mead and Lake Powell, respectively. • Incremental changes in fugitive dust emissions are directly proportional to the changes in exposed shoreline area. Although some portions of exposed area would have varying potential to generate fugitive dust, it is assumed that these areas are distributed proportionally throughout the potential range of reservoir surface elevations. Therefore, exposed areas were assumed to have a similar emission rate for a given amount of exposed shoreline. It should be noted, however, that estimated fugitive dust emissions were not calculated for this analysis, and it is likely that certain areas of the exposed shoreline would be expected to have higher emission rate factors than others. For example, delta areas with high amounts of fine sediment deposit would be a more likely source of fugitive dust generation than more compact or rocky soils at other exposed locations. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.11-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 388 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Based on these assumptions and using modeling results associated with projected median surface elevations for Lake Powell and Lake Mead, potential changes in shoreline exposure under baseline conditions and the interim surplus criteria alternatives were identified. 3.11.2.2 AFFECTED ENVIRONMENT Ambient conditions in the Las Vegas (Lake Mead) area are characterized by low annual precipitation and generally light winds. Windrose data for the Las Vegas area for the period 1992 through 1996 indicate the predominant wind directions to be from the west, southwest, and south (i.e., away, rather than toward the Las Vegas metropolitan area) throughout the year. Wind speeds are less than five miles per hour (mph) for approximately 25 percent of the year and greater than 25 mph for less than one percent of the year. The average wind speed is approximately nine mph. Ambient conditions are similar for the Lake Powell area. Windrose data for Page, Arizona for the period 1992 through 1996 indicates there is no predominant wind direction. Rather, wind direction is somewhat evenly distributed, with the exception of winds from the southeast occurring less frequently. Wind speeds are less than five mph for more than 65 percent of the year and greater than 20 mph for less than one percent of the year. The average wind speed is less than five mph. erior Int f the 9, 2017 border. Lake Mead is located on the Nevada (Clark County)/Arizona (Mohave County) pt. o er 2 . De the federal Clean Air Act, in the Air quality regulations, including implementation ofovemb nv at Clark n N Ntheio d oCounty Air Pollution Control Division Lake Mead area are administered by vajo ve (Nevada) and the Arizona Departmenthi Environmental Quality (ADEQ). Air quality in Na 4, arc of d cite 1686 regulations in the Lake-Powell area, which is located on the Arizona/Utah border, are 4 administered by o. 1 N the ADEQ and the Utah Department of Environmental Quality, Division of Air Quality. Pursuant to the federal Clean Air Act, as amended in 1990, the EPA has established National Ambient Air Quality Standards (NAAQS) for a number of air pollutants, which are considered harmful to public health or the environment. There are two types of NAAQS, primary and secondary. Primary standards are designed to set limits for the protection of public health, including the health of sensitive populations (receptors) such as asthmatics, children and the elderly. Secondary standards are designed for the protection of the public welfare, including visibility as well as damage to animals, crops, vegetation and buildings. The EPA has established annual average and 24-hour average NAAQS for particulate matter of less than 10 microns in diameter (PM10) and particulate matter of less than 2.5 microns in diameter (PM2.5). Although the PM10 standards have been in effect for some time, the PM2.5 standards are more recent (1997). Because development of baseline data for the latter is an ongoing effort and final implementation of the PM2.5 standards may not occur for years, the discussion of fugitive dust emissions focuses on PM10, which are more commonly understood and encompass PM2.5 emissions in any event. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.11-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 389 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Fugitive dust emissions such as those from exposed reservoir shorelines can contribute to PM10 concentrations. To the extent that exposed shoreline is characterized by relatively fine or light soils, fugitive dust emissions can result. However, given the apparent nature of the reservoir shorelines (more gravel surface than soil) and the relatively low average winds in the reservoir areas, soil materials from exposed shoreline areas do not appear to result in significant fugitive dust emissions. Another possible source of particulate emissions is from the deposition of dried plant material left along the shoreline as the water level recedes. Given the nature of the lakes’ bottom compositions and the relatively slow rate of reservoir water level decreases, it is unlikely that this type of emissions source would be significant. The lakes do not appear to contain high levels of algae, and the water levels are projected to decline by a few feet per year (relative to baseline conditions). At this rate, algae or other forms of plant matter would be likely to recede with the water rather than be deposited along the shoreline. Particulate emissions in the Lake Mead and Lake Powell areas do not appear to be a significant problem. While some urban areas (including Las Vegas, North Las Vegas and Henderson) within Clark County are not in attainment of the NAAQS for PM10, the rest of the county, including Lake Mead, is in attainment of the standard. The portion ior Inter PM10 standard. e of Mohave County adjacent to Lake Mead is also in attainment of the 017 of th 29, 2 The northern central Arizona and southern UtahDept. area, including Lake Powell, is also in . ber attainment of the PM10 standard. This attainment status corresponds with windrose ion v Novem Nat information for both areas (i.e., relatively ed on vajo hiv low average wind speeds implying low wind a blown dust emissions in N 4, arc the relatively low levels of dust generated from ited on average) and c 86 human activities. 4-16 No. 1 Since both lake areas are used primarily for recreational purposes, there are limited sensitive receptor population concentrations such as asthmatics, children or elderly living in these areas. 3.11.2.3 ENVIRONMENTAL CONSEQUENCES Based on modeled median surface elevations, baseline conditions will likely result in decreased reservoir water levels and increases in exposed shoreline for both Lake Mead and Lake Powell over the period of analysis. Median elevations under each of the alternatives indicate a similar potential for increased shoreline exposure over time. Tables 3.11-1 and 3.11-2 indicate Lake Mead and Lake Powell median surface elevations identified through modeling (described in Section 3.3), as well as reservoir surface area and exposed shoreline (based on shoreline slope estimates discussed in Section 3.11.2.1) associated with these elevations. The greatest difference in exposed shoreline between baseline conditions and each of the alternatives would generally occur in the first half of the modeled period, as indicated under years 2016 and 2026 in Tables 3.11 and 3.11-2. By year 2036, there are relatively minor variations in exposed COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.11-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 390 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 shoreline associated with the median elevations under the alternatives as compared with baseline projections. Specifically, modeling results indicate an increased potential for fugitive dust emissions under the Basin States, Six States, California and Shortage Protection alternatives when compared with baseline projections throughout the initial, approximately 35 to 40 years of the projections, with the greatest differences in shoreline exposure potential occurring at or near the end of the interim period, in the year 2016. The Flood Control Alternative would have a slightly decreased potential for fugitive dust emission over the entire period of analysis when compared with baseline conditions. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.11-4 CHAPTER 3 1143 Basin States Alternative 1125 1126 2026 1120 1121 2036 1 1111 1111 2050 108.1 120.2 2016 99.3 99.8 2026 97.4 97.6 2036 Reservoir Surface Area (acres x1000) 93.6 93.6 2050 56.3 42.3 2016 66.4 65.9 2026 68.6 68.4 2036 Exposed Shoreline Area (acres x1000) 2 1162 1128 1119 1111 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 2 1 Flood Control Alternative 120.2 3.11-5 100.7 96.8 93.6 42.3 64.8 69.3 ior Inter54.8 17 66.4 68.5 Six States 1145.5 1124.7 1120.4 1110.6 109.4 99.3 97.5 93.6 e Alternative of th 29, 20 t. California 1131.2 1116.4 1117.6 1110.6 102.1 D p m 93.6 63.2 70.4 69.9 .95.9 e 96.3 ber v Alternative ation on Nove N 101.7 Shortage 1117.6 1110.6 96.3 93.6 63.7 69.7 69.9 1130.2 1117.9 vajo hived 96.5 Protection Na c Alternative ar ed in 8 citsurface elevations. 64, Based on modeled median reservoir 6 Area of exposed shoreline represents the area -1 would be exposed below the full pool elevation of Lake Mead for the various water surface elevations indicated, 14 that Lake Mead’s water surface area is 156,845 acres at water surface elevation of 1219.6 feet msl. assuming an average shoreline slope of 30 degrees. No. 1162 2016 Baseline Conditions Scenario Surface Elevation (feet msl) 73.0 73.0 73.0 73.0 73.0 73.0 2050 Table 3.11-1 Median Lake Mead Surface Elevation, Surface Area and Exposed Shoreline Area Under Baseline Conditions and Alternative Projections AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 391 of 1200 CHAPTER 3 3665 2016 3666 2026 3670 2036 1 3663 2050 134.6 2016 135.2 2026 138.0 2036 Reservoir Surface Area (acres x1000) 132.6 2050 37.0 2016 36.2 2026 32.2 2036 Exposed Shoreline Area (acres x1000) 2 3664 3666 3670 3663 134.1 135.2 138.0 132.6 37.7 36.2 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.11-6 assuming an average shoreline slope of 45 degrees. Lake Powell’s water surface area is 160,782 acres at water surface elevation of 3700 feet msl. 2 1 Basin States Alternative 32.2 39.9 39.3 39.9 37.6 39.9 39.9 2050 ior I er 17 36.2 32.2 Flood Control 3665 3666 3670 3665 134.6 135.2 138.0 134.2nt 37.0 e Alternative of th 29, 20 t. Six States 3664 3666 3670 3663 134.1 135.2 ep 138.0 132.6 37.7 36.2 32.2 er .D Alternative nv emb tio 131.6 ov California 3660 3661 3670 3663 Na jo 130.8ed on N 138.0 133.0 42.4 41.3 32.2 Alternative Nava archiv in Shortage 3659 3661 4, Protection cited 36706863663 130.2 131.6 138.0 132.6 43.2 41.3 32.2 Alternative -1 o. 14 Based on modeled median surface elevations. N Area of exposed shoreline represents the area that would be exposed below the full pool elevation of Lake Powell for the various water surface elevations indicated, Baseline Conditions Scenario Surface Elevation (feet msl) Table 3.11-2 Median Lake Powell Surface Elevation, Surface Area and Exposed Shoreline Area Under Baseline Conditions and Alternative Projections AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 392 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 393 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.12 VISUAL RESOURCES 3.12.1 INTRODUCTION This visual resource analysis addresses the scenic resources at Lake Mead and Lake Powell. The analysis centers on the potential effects of increased shoreline exposure that could result from implementation of the interim surplus criteria alternatives considered in this document. 3.12.2 METHODOLOGY The evaluation of the effects of the alternatives on the visual resources is based on an assessment of the changes in reservoir shorelines caused by potential decreases in reservoir water surface elevations. More precisely, the modeling indicates the increased range of water level swings between the highs when reservoirs are full and the lows that could occur when the Colorado River Basin natural runoff is low. The potential water level lows have been described in Section 3.3 in terms of probability of occurrence, based on operation model output. Consequently the visual effects are also presented in terms of the probabilities of shoreline changes. Owing to the subjective nature of visual qualities, this analysis is presented as a qualitative assessment of potential visual effects. rior Inte 17 f the of exposed shoreline 20 Changes in water elevation have differing effects on theo ept. amount 29, r D mb lake depending on topography; the analysis tion v. changes in e levels to shoreline relates the a interpretedofrom existing topographic maps. N ve topography. The shoreline changesN on jo were Nava archivedis derived from NPS documents and The description of the iaffected environment n cited 16864, commercial maps and literature describing scenery in the LMNRA and the GCNRA. 14No. 3.12.3 AFFECTED ENVIRONMENT Both Lake Mead and Lake Powell are situated in desert areas of the Colorado River Basin. While the desert vistas at the reservoir sites have a certain scenic attractiveness of their own, the reservoirs have added a contrasting visual element that increases the visual attractiveness of the areas, which are now dedicated as national recreation areas. The uniqueness of the reservoirs with their contrasting surroundings has been widely illustrated in travel and vacation literature, and has formed well known visual images which help to draw multi-day visitors seeking water related recreation, and touring motorists making day visits. The reservoir water levels fluctuate both yearly and, to a lesser degree, seasonally. During high runoff years reservoir inflows exceed the required releases and water is stored, causing the water level to rise. During lower runoff years, when releases are greater than inflows, water levels decline. The effects of water level changes on visual qualities in the GCNRA and LMNRA depend greatly on the distance from which the shoreline is viewed, and the type of topography forming the shoreline. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 394 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.12.3.1 CHAPTER 3 LAKE POWELL Glen Canyon National Recreation Area is located in the Canyonlands area of the Colorado Plateau. The plateau includes parts of Utah, Colorado, New Mexico, and Arizona and is drained by the Colorado River and its many tributaries. The primary attraction of the GCNRA is Lake Powell, a 186-mile-long reservoir on the Colorado River that is formed by Glen Canyon Dam. Lake Powell extends along what was once the Colorado River, through Glen Canyon and numerous side canyons to form more than 1960 miles of reservoir shoreline. Recreationists enjoy exploring the endless side channels and canyons of the reservoir by boat, often spending several days on the water in houseboats or camping in remote areas. The combined qualities of visual attractiveness and branching waterways create an attraction for many recreationists. 3.12.3.1.1 Landscape Character In “carving” out the canyon landforms, the Colorado River and its tributaries formed a labyrinthine pattern of deep twisted canyons whose towering walls exhibit the geological history of the region. The sedimentary rock formations show multihued sandstone and limestone layers and change color under differing sun angles occurring during the day. Much of the land surface is bare rock with no soil cover. With little erior soil cover or moisture, there is minimal vegetation and littlehe Int relief from the sun and the 017 ft winds that blow across the vast plateau. Consequently, o terraced,plateau landscape pt. the er 29 2 De b above the canyon walls displays the vaston v. of ovesandstone and limestone. i expanse N red m at on These red, orange and beige rocko N j formations result in a dramatic landscape of towering Nava ofaslickived and steep-sided canyons. Since the filling rock spires, undulatingn i plateaus , rch rock 4 cited decades ago, a dramatic contrast to this arid red rock of Lake Powell several-1686 4 1 environment evolved in the form of the deep blue waters of Lake Powell, with their No. erratic patterns on the landscape likened to a blue lightening bolt in the red-orange desert. Secluded side canyons support cottonwoods and poplars because of the shelter from the wind provided by the canyon walls, and presence of water from tributaries. Tamarisk, a non-native, invasive species, thrives along the lakeshore and in stream bottoms, wherever it can find abundant water, forming a ring of green vegetation along the less steep slopes of the reservoir. The reservoir and its protected surroundings in the GCNRA form a valued recreation resource. 3.12.3.1.2 Sensitive Viewing Locations The shoreline of Lake Powell and its adjacent landscape can be viewed from the surrounding land at Glen Canyon Dam and its vicinity and from limited areas of the canyon rim, notably the recreation-oriented area extending upstream of the lake from the west end of the dam. Access by boat permits the greatest amount and variety of scenic vistas; boaters generally look forward to viewing canyon scenery during their visit to the area. The vistas are relatively short in relation to the surface area of the lake, because of the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 395 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 sinuous shape of the lake, and the fact that much of the area lies in side canyons and isolated basins along the meandering course of the former Colorado River corridor. When Lake Powell water level declines, a white band of calcium carbonate appears on rock surfaces where cliffs or rocky slopes form the reservoir rim. In areas where the lakeshore consists of sand and gravel, an exposed beach belt emerges. 3.12.3.2 3.12.3.2.1 LAKE MEAD Landscape Character Lake Mead is situated in the northern part of the Mojave Desert and is surrounded by an austere desert landscape. The lake extends about 66 miles upstream from Hoover Dam and has about 695 miles of irregular shorelines with large bays and small coves. Lake Mead is framed by low mountains with jagged rocky faces and profiles. Intervening canyons and washes provide variation to the terrain, with the combination presenting an interesting rugged type of scenery for many visitors. While the landscape at midday is relatively subdued in terms of color, the contrast with the blue water of the lake provides an appealing scenic area for visitors. Moreover, the contrasting “moods” ior of the surrounding desert visible between sunrise and sunset createter In memorable scenic f the 9, 2017 experiences. pt. o 2 . De ber ion v Novem 3.12.3.2.2 Sensitive Viewing Locations on Nat vajo hived in Na 4, corridor where Lake Mead is located consists of rc The portion of cited the Colorado Rivera 86 -16 alternating narrow. rocky canyons and wide alluvial basins. Most of the lake and its o 14 N shoreline is visible only to people at widely scattered access points and from boats on the lake. The major exceptions are the broad Hemenway Wash area on the west side of the Boulder Basin of the lake, the Las Vegas Bay area on the west side of Boulder Basin and Hoover Dam. The Hemenway Wash area is a broad colluvial fan extending upslope from the lake to the River Mountains on the west, with one contiguous area named Hemenway Valley extending upslope southward and forming the northern part of Boulder City. At the lake shore, the broad expanse of gradually sloping desert terrain has been developed into a series of water-based recreation areas, consisting of, in a northward direction, Hemenway boat launching area and water craft area (boating area with launching ramps, docks, and shoreline areas designated for personal water craft use), the Boulder Beach area, a largely unimproved gravel beach area for recreation including swimming, windsurfing and sunbathing, with an adjacent overnight campground and a mobile home community, and then the Lake Mead Marina, providing a boat berthing area, restaurant and boat launching and docking facilities. Westerly of the shoreline area, up the sloping desert terrain, is the boundary between the LMNRA and the beginning of the Hemenway Valley section of Boulder City. This area COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 396 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 has been extensively developed with condominiums and homes ranging in price up to millions of dollars, with much of the area having been developed to take advantage of lake vistas and views of the surrounding hills and desert landforms. Las Vegas Bay to the north is a relatively narrow area of Lake Mead that is the initial vista presented to people driving to the lake from the Las Vegas Valley. Vistas of the lake are distant because the roads serving the area tend to be on benches above the lake from which direct views of the shoreline are distant and intermittent. Hoover Dam is at the south end of a narrow, steep-walled canyon, which is visible only from the dam and the Arizona abutment and visitor parking areas. When Lake Mead water level declines, two elements of the area’s vista are readily visible. One element is the exposed beach belt around the perimeter of the reservoir where the bottom consists of sand and gravel. The other element is a white band of calcium carbonate on rock surfaces where cliffs or rocky slopes form the reservoir rim. 3.12.4 ENVIRONMENTAL CONSEQUENCES 3.12.4.1 BASELINE CONDITIONS ior Inter 17 f the 9, 0 pt. o conditions2would fluctuate r2 D The water surface elevation of Lake Powell undere m e n v. baseline b e between full level and lower level, with ithe amount ov duration of fluctuation Nat o d on Nand ajo Colorado River system. Moreover, the potential v depending on natural runoff in the rchive in Na 4, a dwould increase with the passage of time as the Upper Divisions range of fluctuations cite 1686 states increase their 14- of river water. An annual fluctuation of approximately 20 feet use No. is projected, in step with the seasonal runoff cycle. Considering the annual fluctuation, 3.12.4.1.1 Lake Powell the "average full" Lake Powell elevation for this analysis is considered to be an average of approximately 3690 feet msl. While the timing of major water level variations can not be predicted, nor the length of time the water level would remain at the full level or at any other specific level, the probable range of future baseline water levels has been estimated by the model. As shown on Figure 3.3-6, the median water level decline would be 25 feet below the average full level by the end of 15 years, after which the median level would remain at or above that decline to 2050. There is also a 10 percent probability that the water level would decline as much as 75 feet below the average full level by the end of 15 years, and as much as 135 feet by 2050. However, as noted above, these lows would be temporary, with a likelihood that the reservoir level would fluctuate up to full level when high natural runoff conditions occur. The declines cited above represent the average water levels under an annual 20-foot variation. The visual consequences of such water level declines would affect boaters viewing two types of shoreline. First, colorful sandstone canyon walls could show a white band of COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 397 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 calcium carbonate deposit between the full water level and the lower water level, which would detract from the visual contrast of rock and water. Second, the shoreline areas consisting of sandy or gravelly desertscapes with their unique desert vegetation would be altered by the interposition of a beach belt of sand and gravel between the full water level and the lower water level. This could also alter the contrasting contact between the blue water and the natural desert, and in some cases, distance boaters from the natural terrain. 3.12.4.1.2 Lake Mead As described in Section 3.3, the water surface elevation of Lake Mead under baseline conditions would fluctuate between a full pool and increasingly lower lake levels, with the amount and duration of fluctuations depending on natural runoff in the Colorado River system. The potential range of fluctuations would increase with the passage of time as the Upper Division states increase their use of river water. While the timing of major water level variations can not be predicted, nor the length of time the water level would remain at the full level or at any other specific level, the probable range of water levels has been estimated by the model. An annual fluctuation of 10 to 20 feet is projected, in step with the seasonal runoff cycle. Considering the annual fluctuation, the "average full" Lake Mead elevation for this analysis is considered itorbe an average ter o of approximately 1215 feet msl. he In 017 ft ,2 t. o Dep mber 29 .level would decline 50 feet below the As shown on Figure 3.3-13, the median iwater nv ve Nat o d on Nothe median decline would continue average full level by the end va15 years, after which of jo e to 105 feet by 2050.dThere is alsoar10 percent probability that the median water level in Na 4, a chiv c te 1 120 would decline asi much-as686 feet below the average full level by the end of 15 years, 4 180 feet by the end 1 30 years, and then continue a gradual decline to 200 feet by 2050. No. of However, as noted above, these lows would be temporary, with the probability that the level of Lake Mead level would fluctuate up to full level when high natural runoff conditions occur. The visual effect of such a decline perceived by the public would vary depending on the proximity to the reservoir. Persons close to, or on, Lake Mead would perceive that the water level had dropped greatly. However, along most of the alluvial shoreline the exposed bottom would exhibit expanses of gravel. Boaters viewing cliff shorelines would see a band of white calcium carbonate deposits that would probably detract from their appreciation of the rock walls. Persons outside the LMNRA could notice a reduction in reservoir level, depending on their distance from the lake and the degree of visibility of the lake shore. However, beyond the alteration of the water shoreline and the increased prominence of islands and outcrops in the lake, no degradation of the viewshed would be anticipated. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 398 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.12.4.2 3.12.4.2.1 CHAPTER 3 BASIN STATES ALTERNATIVE Lake Powell Under this alternative the median water level would decline 25 feet below the average full level by the end of 15 years, after which the median decline would be virtually the same as under baseline conditions to 2050. There is also a 10 percent probability that water level would temporarily decline as much as 85 feet below the average full level by the end of 15 years, and continue a gradual decline to 140 feet by 2050. However, as noted above, these lows would be temporary, with a likelihood that the reservoir level would fluctuate up to full level when high natural runoff conditions occur. The declines cited above represent the average water levels under an annual 20-foot variation. The visual consequences would involve the same scenic changes described above for baseline conditions. 3.12.4.2.2 Lake Mead Under this alternative the median water level would decline 70 feet below the average full level by the end of 15 years, after which the median decline would reach 105 feet ior by 2050. There is also a 10 percent probability that water level would temporarily Inter 17 he decline as much as 135 feet below the average full levelof tthe end of20 years, and 205 pt. by er 29, 15 e feet by the end of 30 years and during the n v. D periodb 2050. However, as noted ioremainingovem tothe reservoir level would Na d likelihood that above, these lows would be temporary,twith aon N vajo natural runoff conditions occur. fluctuate up to full level when high rchive in Na a cited 16864, 14The visual consequences would involve the same scenic changes described above for No. baseline conditions. 3.12.4.3 3.12.4.3.1 FLOOD CONTROL ALTERNATIVE Lake Powell Under this alternative the Lake Powell water levels would be virtually the same as under baseline conditions. The visual consequences would involve the same scenic changes described above for baseline conditions. 3.12.4.3.2 Lake Mead Under this alternative Lake Mead water levels would be virtually the same as under baseline conditions. The visual consequences would involve the same scenic changes described above for baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 399 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.12.4.4 3.12.4.4.1 CHAPTER 3 SIX STATES ALTERNATIVE Lake Powell Under this alternative the median water level would decline 25 feet below the average full level by the end of 15 years, after which the median decline would be virtually the same as under baseline conditions to 2050. There is also a 10 percent probability that water level would temporarily decline as much as 85 feet below the average full level by the end of 15 years, and continue a gradual decline to 140 feet by 2050. However, as noted above, these lows would be temporary, with a likelihood that the reservoir level would fluctuate up to full level when high natural runoff conditions occur. The declines cited above represent the average water levels under an annual 20-foot variation. The visual consequences would involve the same scenic changes described above for baseline conditions. 3.12.4.4.2 Lake Mead Under this alternative the median water level would decline 70 feet below the average full level by the end of 15 years, after which the median decline would reach 105 feet ior by 2050. There is also a 10 percent probability that water level would temporarily Inter 17 he decline as much as 130 feet below the average full levelof tthe end of20 years, and 205 pt. by er 29, 15 e feet by the end of 30 years and during the n v. D periodb 2050. However, as noted ioremainingovem tothe reservoir level would Na d likelihood that above, these lows would be temporary,twith aon N vajo natural runoff conditions occur. The visual fluctuate up to full level when high rchive in Na a itedinvolve 64,same scenic changes described above for baseline c consequences would 168 the conditions. No. 14 3.12.4.5 3.12.4.5.1 CALIFORNIA ALTERNATIVE Lake Powell Under this alternative the median water level would decline 30 feet below the average full level by the end of 15 years, after which the median decline would be virtually the same as under baseline conditions. There is also a 10 percent probability that the water level would decline as much as 95 feet below the average full level by the end of 15 years, and continue a gradual decline to 140 feet by 2050. However, as noted above, these lows would be temporary, with a likelihood that the reservoir level would fluctuate up to full level when high natural runoff conditions occur. The declines cited above represent the average water levels under an annual 20-foot variation. The visual consequences would involve the same scenic changes described above for baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 400 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES 3.12.4.5.2 CHAPTER 3 Lake Mead Under this alternative the median water level would decline 85 feet below the average full level by the end of 15 years, after which the median decline would reach 105 feet by 2050. There is also a 10 percent probability that water level would temporarily decline as much as 145 feet below the average full level by the end of 15 years, and 210 feet by the end of 30 years and during the remaining period to 2050. However, as noted above, these lows would be temporary, with a likelihood that the reservoir level would fluctuate up to full level when high natural runoff conditions occur. The visual consequences would involve the same scenic changes described above for baseline conditions. 3.12.4.6 3.12.4.6.1 SHORTAGE PROTECTION ALTERNATIVE Lake Powell Under this alternative the median water level would decline 30 feet below the average full level by the end of 15 years, after which the median decline would be virtually the same as under baseline conditions to 2050. There is also a 10 percent probability that ior the water level would decline as much as 95 feet below the averageer level by the end Int full 17 the of 15 years, and continue a gradual decline to 140 feet.byf2050. 29, 20 as noted pt o er However, e b above, these lows would be temporary lows, v. D a likelihood that the reservoir level ion with Novem at natural runoff conditions occur. The declines would fluctuate up to full level when high ajo N d on cited above represent the Nav waterilevels under an annual 20-foot variation. average rch ve in a cited 16864, 14The visual consequences would involve the same scenic changes described above for No. baseline conditions. 3.12.4.6.2 Lake Mead Under this alternative the median water level would decline 85 feet below the average full level by the end of 15 years, after which the median decline would reach 105 feet by 2050. There is also a 10 percent probability that the water level would temporarily decline as much as 140 feet below the average full level by the end of 15 years, and 210 feet by the end of 30 years and during the remaining period to 2050. However, as noted above, these lows would be temporary, with a likelihood that the reservoir level would fluctuate up to full level when high natural runoff conditions occur. The visual consequences would involve the same scenic changes described above for baseline conditions. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.12-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 401 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.13 CULTURAL RESOURCES 3.13.1 INTRODUCTION Cultural resources include prehistoric and historic districts, sites, buildings, structures, objects and landscapes. Historic properties are cultural resources that meet one or more of the Secretary’s criteria of significance found at 36 CFR 60.4 and are listed on, or have been found eligible for inclusion, in the National Register of Historic Places (NRHP). The term also includes sites of traditional religious and cultural significance to an Indian Tribe that meet one or more of the NRHP criteria – traditional cultural properties. Section 106 of the National Historic Preservation Act (NHPA) of 1966, as amended, requires all federal agencies to take into account the effects of their actions on historic properties. 3.13.2 APPROACH TO ANALYSIS The first step in the Section 106 process, as set forth at 36 CFR 800.3(a), is for the Agency Official to determine if a proposed action meets the definition of an undertaking. An “undertaking” is defined at 36 CFR 800.16(y) as “a project, activity, or program funded in whole or in part under the direct or indirect jurisdiction of a ior Inter agency; those federal agency, including those carried out by or on behalf the federal 17 0 f of a carried out with federal financial assistance; thoseept. o a federal 2 requiring r 29, permit, license or v. D mbe approval; and those subject to State or local regulation administered pursuant to a ation The Nove has the authority to declare jo agency.” on Secretary delegation or approval by a federal N ved Nava artheiLROC developed pursuant to the Colorado surplus conditionsed inreference to ch with , 4 cit River Basin Project Act,1686 make surplus determinations during the AOP 4- and to 1 development process. Using the existing LROC and AOP process, the Secretary has No. declared the existence of surplus conditions every year since 1996 and could continue to do so in the absence of interim criteria. Reclamation has determined development and implementation of interim surplus criteria for use in conjunction with the LROC and AOP process has the potential to temporarily change the way in which surplus is determined for the period 2000-2015. Development and implementation of interim surplus criteria can thus be construed as a temporary change in an ongoing activity that is part of an existing program, the latter being the delivery of Colorado River water. Thus, it meets the definition of an undertaking for the purposes of complying with Section 106 of the NHPA. The second step in the Section 106 process is to determine if the undertaking has the potential to cause effects to historic properties. If an undertaking “does not have the potential to cause effects on historic properties,” pursuant to 36 CFR 800.3(a)(1), the Agency Official has no further obligations under Section 106. Effect is defined at 36 CFR 800.16(i) as “alteration to the characteristics of a historic property qualifying it for inclusion in or eligibility for the National Register.” Reclamation has determined development of interim surplus criteria is an undertaking, but one without potential to COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.13-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 402 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 affect historic properties. Reclamation’s rationale for this determination is outlined below. 3.13.3 AFFECTED ENVIRONMENT The term area of potential effects (APE) is defined at 36 CFR 800.16(d) as “the geographic area or areas within which an undertaking may directly or indirectly cause changes in the character or use of historic properties, if any such properties exist.” This section goes on to state “the area of potential effects is influenced by the scale and nature of an undertaking and may be different for different kinds of effects cause (sic) by the undertaking.” For the purposes of evaluating the potential for development and implementation of interim surplus criteria to affect historic properties, the APE has been differentially defined for Lake Powell, Lake Mead, the Grand Canyon, and the reservoirs and river corridor from below Hoover Dam to the SIB. This is to address the effects of changes in lake elevations and mean monthly flow rates predicted by the hydrological modeling runs presented earlier in this EIS, and other factors. The APE definitions used in this analysis are as follows: Lake Powell: That area around the margin of the lake extending from the historic maximum pool elevation of 3708 feet msl, to the 3595-foot contour. rThe 3595-foot e ior contour has been selected as the low elevation cutoff point,the Int as hydrological modeling 017 f runs indicate there is a 10 percent probability the surface elevation9, 2 lake could pt. o er 2 of the De Alternative. b drop to this level by 2016 for the Shortagen v. io Protection vem t o a N aj N vtheolakehived on Lake Mead: That area iaround n Na arc margin extending from its historic high water ited feet864, The 1083-foot contour has been selected as the low level of 1225.5c 1083-16 msl. to 1 elevation cutoff point4 this represents the minimum pool level necessary for continued No. as power generation. The maximum flood pool elevation is 1229 feet msl. Colorado River through the Grand Canyon: As discussed in Section 1.4.2, the Glen Canyon EIS analyzes the effects of operation of Glen Canyon Dam on downstream resources of the Grand Canyon, including cultural resources. The Record of Decision (ROD) for this EIS provides for monitoring and management of affected cultural resources. Section 106 compliance for existing operations and implementation of surplus criteria are and will be subject to the Cultural Resources Programmatic Agreement prepared with respect to the operation of Glen Canyon Dam. Thus it will not be considered further in this analysis. Colorado River from Hoover Dam to SIB: Downstream from Hoover Dam, the Colorado River flows through a relatively narrow valley along which are located Lake Mohave and Davis Dam, Lake Havasu and Parker Dam, and a series of smaller dams that serve to impound and divert water for specific purposes. As indicated in Section 3.3.4, although Lake Mohave and Lake Havasu are located within the overall APE of the current action, implementation of interim surplus criteria will have no effect on the surface elevations or operation of these reservoirs. As a consequence, they are not COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.13-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 403 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 considered further in this analysis. Below Davis and Parker dams, the river is fringed by riparian vegetation and marshy backwaters, and a series of levees serve to contain its flow. Because under all but the most exceptional circumstances (e.g., a catastrophic flood event, levee failure, etc.), the flow of the Colorado River is expected to be contained within its channel and the levees, and the APE for free-flowing stretches is considered to be the river channel and that area of the floodplain lying within the levees. 3.13.4 ENVIRONMENTAL CONSEQUENCES The No Action and each of the action alternatives could result in changes in the surface elevations of Lake Powell and Lake Mead and changes in release patterns and flow of the Colorado River below Hoover Dam. These changes could result in changes in erosional and/or depositional processes that could affect historic properties, were such properties present. However, Reclamation considers the probability for the existence of cultural resources retaining qualities that would qualify them for listing on the NRHP within the interim surplus criteria APEs, as defined above, to be extremely low. Although Hoover and Glen Canyon dams were constructed prior to passage of the NHPA in 1966, attempts were made to locate and salvage information from significant prehistoric and historic archaeological sites prior to inundation by Lake Mead and Lake erior Powell. As a result of these efforts, numerous kinds of siteshe Int masonry including 17 20 of t structures, wattle and daub roomblocks, rockshelters,tlithic and ceramic scatters, trails, ep . ber 29, D m shrines, quarry locations, salt mines, andon v. towns, mills, roads, etc., are known to historic atilakes.on Nove N be submerged beneath the waterso the ed vaj of iv Na arch d in itecondition 64,the No Action Alternative, impacts that are likely to c Under the baseline -168 for . 14inundated by the reservoirs can be expected to vary in kind and have occurred No to sites degree, depending on a number of factors including the type of site, slope, the substrate on which the site is located, the site’s elevation with respect to historic operation of the reservoir, the number of times a site has been inundated, exposed and re-inundated, etc. In areas where the lake margins make contact with unconsolidated sediments (i.e., alluvial fans, fluvial deposits, etc.), wave action and rising and falling water levels can cause cutting and bench formation, exposure and removal of finer-grained sediments, and sorting and redistribution of coarser materials in the sediment matrix along the slope of the bench or beach. If offshore currents are present, materials may be redistributed along the direction of flow. Where lake margins intersect with lenses or large exposures of poorly consolidated bedrock (e.g., carbonate cemented sandstones, formations containing large quantities of gypsum, etc.), rising and falling water coupled with wave action can, over time, result in undercutting and collapse. Lithic artifacts may suffer edge damage or become water-worn, bone items may be splintered or deteriorate completely, and entire classes of cultural materials (i.e., basketry, vegetal food remains, etc.) can be lost as a result of repeated episodes of exposure and inundation. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.13-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 404 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 In general, sites within the range of a reservoir’s historic high and low elevations that have been repeatedly inundated and exposed can be expected to have suffered the greatest amount of damage. Since its equalization with Lake Mead in 1974, surface elevations for Lake Powell have fluctuated between 3708 and 3627 feet msl. Sites located between these elevations can thus be expected to have suffered moderate to severe levels of inundation damage and are unlikely to have qualities that would qualify them for consideration as historic properties eligible for potential listing on the NRHP. Modeling runs indicate there is a 10 percent probability the surface level of Lake Powell will drop to 2595 feet msl by 2016. Sites situated between 3627 feet msl and the maximum low of 2595 feet msl predicted by the modeling runs can be expected to have been damaged as the waters of the lake rose, but in the absence of other factors (i.e., strong subsurface currents, landslides, etc.), damage should be less than that anticipated for sites located at higher elevations. Given this, there is a slight possibility sites located between 3627 and 2595 feet might retain some quality that would qualify them for listing on the NRHP. Lake Mead rose to its historic high elevation of 1225.5 feet msl in 1983 and has dropped to its historic low elevation of 1083 feet on two occasions. The first drop occurred during the period extending from 1954 to 1957, while the second occurred or during 1965 and 1966. Sites located between 1225 and 1083 feet msl ican be expected Interto be 7 e to have suffered inundation damage. Damage to all sites f texpected 201 severe given o is h 29, pt.large annual fluctuation range in the 60-plus years the reservoir has been operating,e v. D the mber o 75 reservoir elevation (from 10 to as muchtiasn feet,Noveto the filling of Lake Powell), prior a on ajo N the historic low on two occasions. Reclamation and the reduction in pool elevation to ived Nav considers it is highly unlikely sites exist between elevations of 1225 and 1083 feet msl d in 64, arch cite 168 that will retain any qualities that would qualify them for consideration as historic 14No. properties eligible for potential listing on the NRHP. Development and implementation of interim surplus criteria will result in changes in release patterns and mean monthly flow rates along the Colorado River below Hoover Dam. The results of the hydrological modeling runs for all interim surplus criteria alternatives indicate there will be an increase in mean monthly flow rates from Hoover Dam downstream to Parker Dam, while mean monthly flow rates below Parker Dam will decrease. The Colorado River drains a vast watershed covering portions of seven states. Prior to construction of Hoover Dam, discharge rates along the river varied seasonally, averaging 20,000 cfs with peak flows in excess of 200,000 cfs, making the river extremely dynamic and unpredictable in its behavior. Examination of historic maps during archival work conducted in association with a series of recent cultural resource inventories in the vicinity of Yuma, Arizona (i.e., Bischoff et al., 1998; Huber et al., 1998a, Huber et al., 1998b; Sterner and Bischoff 1998), indicated the Colorado River altered its course several times between the 1840s and the 1950s, in one case meandering two miles across its floodplain. Geomorphological trenching on the floodplain in areas behind the modern levees revealed the presence of sedimentary COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.13-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 405 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 deposits characteristic of a high energy fluvial environment. Such deposits are unlikely to contain in situ cultural remains. Inventory of several parcels located on the floodplain was also revealing. Only recent trash was found on parcels located inside the levee system, while the earliest cultural materials identified on parcels outside the levees did not pre-date construction of the levee. Prehistoric cultural remains were confined to locations on the first terrace above the 100-year floodplain. The site patterning observed during these studies is doubtless applicable in a general way to other valleys along the reach of the Colorado River below Hoover Dam. Flow releases associated with development and implementation of interim surplus criteria will be within existing operational limits. Increases in flow rates for the reach of the Colorado River between Hoover and Parker dams and decreases in flow rates below Parker Dam do not have the potential to cause effects to historic properties, as the river in these areas is entrenched and confined in its channel by a system of levees. Furthermore, studies conducted in the vicinity of Yuma, Arizona, suggest that were bank erosion to occur, sediments adjacent to the current river channel would most likely reflect deposition under high-energy fluvial conditions. Sediments deposited under such conditions are unlikely to contain in situ cultural remains that would possess qualities that would qualify them for consideration as historic properties potentially r eligible for listing on the NRHP. terio 7 he In . of t releases201 p of No surface-disturbing activities will occur as a result t flow er 29, associated with . De b development and implementation of interim surplus ovem as such releases will not ion v N criteria, at require construction of newavajo N Noed on facilities. v modification of existing facilities would be ch in Npotentialrfor iimpacts to the structure or functioning of necessary; thus there is no ited 6864, a cNational Historic Landmark), Parker Dam or Imperial Dam (both of Hoover Dam (a 1 . 14odetermined eligible for listing on the NRHP). which have been N In conclusion, cultural resources that might exist within the APE for Lake Powell and Lake Mead have been repeatedly inundated, exposed, and re-inundated, making it highly unlikely that any retain qualities that would qualify them for consideration as historic properties eligible for listing on the NRHP. Increases and decreases in mean monthly flow rates below Hoover Dam do not have the potential to affect historic properties as flows will be confined to the river channel, which, when not confined by rocky canyon walls, is contained within levees. Were bank erosion to occur, sediments adjacent to the channel are of a type unlikely to contain cultural materials. There is virtually no chance cultural resources retaining qualities that would qualify them for consideration as historic properties potentially eligible for inclusion on the NRHP exist within the APE of the present undertaking. Reclamation thus considers development and implementation of interim surplus criteria to be an undertaking without the potential to affect historic properties. Pursuant to 36 CFR 800.3(a)(1), having determined development and implementation of interim surplus criteria to be an undertaking with no potential to affect historic properties, Reclamation has no further obligations under Section 106 or Part B of 36 CFR 800. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.13-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 406 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Reclamation has prepared a memorandum discussing this issue and has forwarded it to the Advisory Council on Historic Preservation. ior Inter 17 0 f the pt. o er 29, 2 e v. D mb ation on Nove jo N Nava archived in cited 16864, 14No. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.13-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 407 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 3.14 INDIAN TRUST ASSETS 3.14.1 INTRODUCTION Indian Trust Assets (ITAs) are legal assets associated with rights or property held in trust by the United States for the benefit of federally recognized Indian Tribes or individuals. The United States, as trustee, is responsible for protecting and maintaining rights reserved by, or granted to, Indian Tribes or individuals by treaties, statutes and executive orders. All Federal bureaus and agencies share a duty to act responsibly to protect and maintain ITAs. Reclamation policy, which satisfies the requirement of Interior’s Departmental Manual at 512 DM 2, is to protect ITAs from adverse impacts resulting from its programs and activities whenever possible. Reclamation, in cooperation with Tribe(s) potentially impacted by a given project, must inventory and evaluate assets, and then mitigate, or compensate, for adverse impacts to the asset. While most ITAs are located on a reservation, they can also be located off-reservation. Examples of ITAs include lands, minerals, water rights and hunting and fishing rights. ITAs include property in which a Tribe has legal interest. For example, tribal entitlements to Colorado River water rights established in each of the Basin States pursuant to water rights settlements are considered trust assets, and erior t the reservations of these Tribes may or may not be located along the river. The present perfected federal he In 2017 of t reserved rights are rights held directly by the tribal entities for r 29, ept. bethe reservations in whose v. D m name the rights are listed in the Decree.iontribe may also have other off-reservation at A on Nove N into account. o interests and concerns that must jbe taken ed ava v in N rchi ited into64, a c Reclamation has entered 68 government-to-government consultations with potentially 4-1 o identify and address concerns for ITAs. The Tribes include those in affected Tribes to . 1 N the Ten Tribes Partnership whose landholdings are situated along the Colorado River and various tributaries in the Upper and Lower Basins. Additionally, meetings have been held with the central Arizona Tribes served by CAP facilities, the Coachella Valley Consortium of Mission Indians and other interested Tribes within the Lower Colorado Region. Through meetings and discussions among the Tribes, BIA and Reclamation staff (see Chapter 5), the following sections describe ITAs that have been identified to have the potential to be impacted by interim surplus criteria. 3.14.2 TEN TRIBES PARTNERSHIP The Tribes comprising the Ten Tribes Partnership are listed below together with the states in which their reservations are located: COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-1 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 408 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Northern Ute Tribe Jicarilla Apache Tribe Navajo Nation Southern Ute Indian Tribe Ute Mountain Ute Tribe Fort Mojave Indian Tribe Chemehuevi Tribe Colorado River Indian Tribes Quechan Indian Tribe Cocopah Indian Tribe CHAPTER 3 Utah New Mexico Arizona, New Mexico and Utah Colorado Colorado and New Mexico Arizona, Nevada and California California Arizona and California Arizona and California Arizona The CRSS demand database used for the model analysis in this FEIS includes discrete representation of the Ten Tribes’ demand schedules through “demand nodes” in the model. The Tribal demands and their respective points of diversion were obtained from the Tribes in the summer of 2000. The schedules and the full quantified entitlements on which they are based are shown in Attachment Q. The following discussion describes the Ten Tribes’ water rights by Tribe. 3.14.2.1 NORTHERN UTE INDIAN TRIBE – UINTAH AND OURAY RESERVATION erior The Northern Ute Tribe is located in northeastern Utah in the e Int River 7 h Green 20 watershed. . of t two federal1 Quantification of the Tribe’s water rights began inept with r 29, court Decrees D 1923 e that quantified the water rights for the Uintah Indianovemb Project (UIIP). A 1960 Irrigation n v. atio on N report, commonly referred tovajtheN as o “Decker Report,” divided lands on the reservation a groups haved ive into seven groups. ThoseN d in land4, arch served as the basis for discussions of c te 1686 settlement of thei Tribe’s water right claims over the subsequent 40 years. Congress 4ratified a 1990No. 1 tabulation of the Tribe’s water rights in 1992 subject to re-ratification by the Tribe and State of Utah. That tabulation utilizes the Decker Report’s land groups as follows: 1. UIIP lands with water rights decreed by the federal court in 1923, and certified by the State of Utah on the Lakefork, Yellowstone, Uinta and Whiterock rivers. Priority date - October 3, 1861. 2. UIIP lands with water rights certificated by the State of Utah served from the Duchesne River including the towns of Duchesne, Randlett and Myton. Priority date October 3, 1861. 3. Lands that are or can be served from the Duchesne River through UIIP which are not certificated by the state. Priority date would be October 3, 1861. 4. Lands found to be productive and economically feasible to be irrigated from privately constructed ditch systems on the Duchesne River or its tributaries above Pahcease Canal. Priority date would be October 3, 1861. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-2 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 409 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 5. Lands susceptible to irrigation and proposed to be developed within the Central Utah Project. Priority date would be October 3, 1861. 6. Lands east of the Green River served from the White River for which Applications to Appropriate Water were once filed with the State of Utah. 7. Lands east of the Green River found to be productive and economically feasible to be irrigated from privately constructed ditch systems now in operation or to be constructed along the Green River, White River, Willow Creek, Bitter Creek, Sweet Water Creek and Hill Creek. Tables quantifying the Tribe's diversion and depletion rights as tabulated in the 1990 Tabulation (but not yet ratified by the Tribe or state) are included in the Ten Tribes Depletion Schedule (Attachment Q). The diversion rights total approximately 480,000 af with depletions of 248,943 af. The water rights appurtenant to the Group 5 Duchesne Basin lands are proposed to be transferred to the Green River with a seven percent reduction explaining the difference in the table totals. Current water diversions by the Northern Ute Tribe are approximately 250,000 afy for irrigation applications and a small amount of M&I use for oil and gas and a small culinary water system. rior The Northern Ute Tribe has five demand points modeled in he CRSS: two demand the Inte f t River2017 point on points on the Green River, two demand points on the tDuchesne 29, and one p.o . De ember the White River. v ion v t No j Na v vaIo hiRed on A Na 3.14.2.2 JICARILLAin PACHE NDIAN ESERVATION rc ited 6864, a c 1Indian The Jicarilla Apache 4-1 Reservation is located in the upper reaches of the San Juan No. River Basin and the Rio Chama Basin in northwestern New Mexico. The reservation straddles the Continental Divide. Pursuant to the Jicarilla Apache Tribe Water Rights Settlement Act (“Settlement Act”), the Tribe is authorized to divert 40,000 afy from the San Juan River Basin, 32,000 afy of which may be depleted. The Settlement Act provides the Tribe the right to divert 33,500 afy or deplete 25,500 afy from either the Navajo Reservoir supply or directly from the Navajo River as it crosses the Jicarilla Apache Indian Reservation. The Settlement Act also authorizes the Tribe to divert and deplete 6,500 afy from the San Juan River Basin through the transmountain San Juan-Chama Project. The Jicarilla Apache Tribe agreed to subordinate its 1880 priority date for the 40,000 afy (diversion) of “future use” federal reserved water rights in exchange for the 1955 priority date associated with the two federal projects. The Tribe’s agreement to subordinate its 1880 priority date for the 1955 date is discussed in a settlement contract between the Jicarilla Apache Tribe and the Secretary. The settlement contract is ratified by the Settlement Act. These are fully adjudicated rights, which, by virtue of the Settlement Act, the Tribe may market to the full extent that the law allows. The Tribe’s long-term plans for this water include both off-reservation leasing and on-reservation development. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-3 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 410 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 In addition to these “future use” water rights adjudicated in accordance with the Settlement Act, the Jicarilla Apache Tribe also has adjudicated rights to divert 5,683.92 afy or to deplete 2,195 afy, whichever is less, for historic and existing water uses. Thus, the Jicarilla Apache Tribe’s total water diversion rights from the San Juan River Basin amount to 45,683 afy and the Tribe’s overall depletion rights from the San Juan Basin total 34,195 afy. In the CRSS model, the Jicarilla Apache Tribe is represented by four demand points: There is a single node on the upper San Juan River for the current on-reservation uses of the Tribe and those Reclamation assumed were planned for the future. The Tribe’s portion of the San Juan – Chama export diversion is in an existing demand point and does not need to be separated. During 2000, the Jicarilla Apache Tribe anticipates entering into a lease of 16,200 afy through 2025 to Public Service Company of New Mexico for depletion at the San Juan Generating Station. In addition, the Tribe anticipates entering into other short-term off-reservation water leases, ultimately preserving some off-reservation leases in 2060 while allowing the Tribe to use the majority of its San Juan River Basin depletions on-reservation. In order to show the change in water leases, a new demand point has been added to show the Jicarilla water going to the power station and future changes in deliveries. The Tribe is investigating o the feasibility of leasing 7,500 afy of water to the City of Gallup via the r nteri Gallup-Navajo Municipal Water Supply Project. The Jicarilla lease portionhe the project 7 a new of I 01 is ft pt. o er 29, 2 demand point in the CRSS model. . De b nv em Natio d on Nov R ajo 3.14.2.3 NAVAJO INDIANavESERVATION e in N 4, archiv d cite 168 in The Navajo Nation is located6 northeastern Arizona, southeastern Utah and 14northwestern New. Mexico. Navajo reserved water rights to the mainstream Colorado No River, the Little Colorado River and the San Juan River basins are not adjudicated. The Navajo Indian Irrigation Project was authorized by P.L. 87-483. When authorized, the project was envisioned as a gravity irrigated system with an average annual diversion of 508,000 afy, and a resulting depletion of 254,000 afy. Since authorization in 1962, the project has been re-designed as a pressurized sprinkler system with an anticipated average annual diversion of 337,500 afy, and a resulting depletion of 270,500 afy. The priority date for this diversion and depletion is not later than October 16, 1957. The CRSS model includes six demand points for the Navajo Nation. There is a demand point for NIIP on the San Juan River upper reach. Current use and development data listed for the NIIP demand point are from the development schedule in the NIIP Biological Assessment dated June 11, 1999. The Navajo Nation also has a small share in the Animas-La Plata Project (ALP) of 4,680 af of withdrawal and 2,340 af of depletion annually. This future withdrawal and use has been accounted for in the CRSS model by splitting the existing ALP M&I node for New Mexico uses and adding a separate point on the Upper San Juan Reach for the Tribe’s ALP water. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-4 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 411 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Present uses in the San Juan River Basin for project areas other than the NIIP have been quantified in the hydrology models of the basin in the formulation of the Animas-La Plata Project Draft EIS. CRSS demand points exist for the future Gallup-Navajo Project showing 5,000 acre-feet of depletion in Arizona and 17,500 acre-feet of depletion in New Mexico. The existing point was updated to include the Cudei Irrigation Project with the Hogback node, as these projects will soon be combined into a single diversion. A demand point was added to the CRSS to include the existing Fruitland, New Mexico project in the model. Other minor uses on the Navajo Reservation have been included in natural flow calculations and are not included as consumptive demands in the CRSS model. The Navajo Nation currently operates a marina at Antelope Point on Lake Powell. The boat ramp is not operational when the lake level is below elevation 3,677 feet msl. See Section 3.9.2.3.1, Lake Powell, regarding impacts to Lake Powell elevations. 3.14.2.4 SOUTHERN UTE RESERVATION The Southern Ute Indian Tribe is located in southwestern Colorado just west of Navajo Reservoir. The Tribe has settled its water rights pursuant to agreement with the State of Colorado and pursuant to 1988 federal legislation effective Decemberior 1991. The er 19, settlement requires the construction of the Animas-La Plata he Int The 17 has the Project. Tribe of , 2 La . the tAnimas and0 Plata Rivers right to reopen the adjudication of their water rightspt De on implementation. The er 29 if certain agreed upon dates are not mettiregarding projectmb n v. a o of n Nove agreement provides the Tribevajo a varietyd odirect flow rights with priorities ranging with N ve Na from 1868 to 1976 in streams and archi passing through the Southern Ute Reservation. d in , rivers cite 16864 The CRSS model . 14 demand points for the Southern Ute Tribe. In the model, the Nohas two Present Level - Colorado Agriculture demand point on the San Juan River has been split to separate Southern Ute Tribal uses from non-reservation uses. The Tribe also has a right to 39,525 acre-feet of water with 19,762 acre-feet of depletion from the future ALP with a project priority of not later than 1966 for M&I use. To account for the Southern Ute portion of the water use, the demand point in Colorado was split into three to separate Southern Ute, other tribes and non-tribal uses. 3.14.2.5 UTE MOUNTAIN UTE INDIAN RESERVATION The Ute Mountain Ute Tribe is located in the southwestern corner of Colorado with a small part in northwestern New Mexico. The Tribe has settled its water rights pursuant to agreement with the State of Colorado and pursuant to 1988 federal legislation effective December 19, 1991. The settlement requires the construction of the AnimasLa Plata Project. If it should prove impossible to construct this project, the Tribe has the right to reopen the adjudication of their water rights on the Animas and La Plata Rivers. The agreement provides the Tribe with a variety of direct flow rights with priorities COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-5 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 412 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 ranging from 1868 to 1985 in three streams, the Mancos River, San Juan River and Navajo Wash, which pass through the Ute Mountain Ute Reservation. The CRSS model has four demand points for the Ute Mountain Ute Tribe. In the model the Present Level - Colorado Agriculture demand point on the Lower San Juan River was split in two to separate Ute Tribal uses. The Tribe also possesses 25,180 acre-feet of storage with 19,260 acre-feet of depletion per year from the Dolores Project for agricultural and other uses with a project priority of not later than 1963. The Dolores Project is accounted for in the CRSS model at two points, one of which is for the Ute Mountain Tribal water use. The Ute Mountain Ute Reservation will have a share of the water in the future ALP. The Tribe will receive 39,525 af of withdrawal and 19,762 af of depletion rights from the ALP as it is now formulated. This water is intended for M&I use on the reservation. To account for the Ute Mountain Ute portion of the water use, the demand point in Colorado was split into three separate parts: Ute Mountain Ute Tribe, other Tribes and non-Tribal uses. ior Inter 17 0 f the The Fort Mojave Indian Reservation is located in the tLower Colorado River Basin p . o er 29, 2 e .D where Nevada, Arizona and California meet.vThe Tribe possesses present perfected mb ation stem of the e Nov Colorado River in all three of federal reserved water rights from the main on ajo N d the states that contain in Nav land, pursuant to the Decree in Arizona v. California reservation rchive a d , and 1984). Since the original Decree was entered, ci Decrees (1979 and supplementalte 6864 4-1been added to the reservation along with rights to 6.464 acre1,102 acres of No. have land 1 3.14.2.6 FORT MOJAVE INDIAN RESERVATION feet per acre of water as specified in the 1979 Decree. The amounts, including added lands, priority dates, and state where the water rights are perfected, are as follows: Amount (afy) Acreage Priority Date State 27,969 4,327 September 18, 1890 Arizona 75,566 11,691 February 2, 1911 Arizona 103,535 16,018 13,698 2,119 September 18, 1890 California 12,534 1,939 September 18, 1890 Nevada 129,767 20,076 Arizona subtotal Total The Fort Mojave Indian Tribe has exercised its water rights in California in excess of the amounts currently decreed. In it's June 19, 2000 Opinion, the United States COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-6 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 413 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Supreme Court accepted the Special Master’s uncontested recommendation and approved the proposed settlement of the dispute respecting the Fort Mojave Indian Reservation. Under the settlement, the Tribe is awarded the lesser of an additional 3,022 af of water or enough water to supply the needs of 468 acres. The attached tables are estimates of use based upon calculations derived from records of electrical consumption at the various pump stations and are not from measured flows. The CRSS model contains four demand sub points for the Tribe’s water diversions, which are divided among three states. The points are on the Lake Mohave reach of the model, and are further divided into sub points by state. A separate sub point is included for Reservation Land development, but has a diversion of zero af at this time. Current depletion amounts for the CRSS model nodes have been updated to reflect the most recent consumptive use numbers provided by the Lower Colorado River Accounting System (LCRAS) report for calendar year 1998. Future depletions at full development are calculated as the greater of 70 percent of diversion rights and the per acre rate of consumptive use from the LCRAS report multiplied by the full right acreage of the Tribe. 3.14.2.7 CHEMEHUEVI INDIAN RESERVATION erior Int The Chemehuevi Indian Reservation is located in southern tCalifornia near7 Lake f he water rights from the o . reserved 29, 201 t Havasu. The Tribe possesses present perfected federal Dep mber main stem of the Colorado River pursuant n v. Decree in Arizona v. California and to the ove atio supplemental Decrees (1979 vajo N The amounts, priority dates, and state where and 1984). ed on N Na hv the rights are perfected, are as follows: i d in , arc cite 16864 14Amount o. Acreage N (afy) 11,340 1900 Priority Date State February 2, 1907 California The lands of the Chemehuevi Tribe are mostly on the plateau above the shoreline of Lake Havasu. Present agricultural water use is limited. Currently, the CRSS model includes a demand point for the Chemehuevi Reservation on the Lake Havasu reach of the model. Current depletion amounts for the CRSS model nodes have been updated to reflect the most recent consumptive use numbers provided by the LCRAS report for calendar year 1998. Future depletions at full development are calculated as the greater of 70 percent of diversion rights and the per acre rate of consumptive use from the LCRAS report multiplied by the full right acreage of the Tribe. 3.14.2.8 COLORADO RIVER INDIAN RESERVATION The Colorado River Indian Reservation is located in southwestern Arizona and southern California south of Parker, Arizona. The Tribes possess present perfected federal reserved water rights from the main stem of the Colorado River pursuant to the Decree COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-7 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 414 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 in Arizona v. California and supplemental Decrees (1979 and 1984). The amounts, priority dates, and state where the rights are perfected, are as follows: Amount (afy) Acreage Priority Date State 358,400 53,768 March 3, 1865 Arizona 252,016 37,808 November 22, 1873 Arizona 51,986 7,799 November 16, 1874 Arizona 662,402 99,375 10,745 1,612 November 22, 1873 California 40,241 6,037 November 16, 1874 California 3,760 564 May 15, 1876 California 54,746 8,213 717,148 107,588 Arizona subtotal California subtotal Total erior Intthe Colorado River The CRSS Model presently has three demand sub-nodes listed for 2017 f the 9, pt. o diversions are split between Tribe on the reach above Imperial Dam number. The waterber 2 v. De ve ion demands andm separate sub-node for future sub-points for California demands, Nat Arizona n No a v jo h depletion pumped diversions in Arizona.aCurrentived o amounts for the CRSS model nodes in Na rc have been updated to reflect the ,most recent consumptive use numbers provided by the ited 6864 a c -1 LCRAS report for.calendar year 1998. Future depletions at full development are o 14 of 70 percent of diversion rights and the per acre rate of N calculated as the greater consumptive use from the LCRAS report multiplied by the full right acreage of the Tribe. 3.14.2.9 QUECHAN INDIAN RESERVATION (FORT YUMA) The Fort Yuma Indian Reservation (Quechan Tribe) is located in southwestern Arizona and southern California near Yuma, Arizona. The Tribe possesses present perfected federal reserved water rights from the main stem of the Colorado River pursuant to the Decree in Arizona v. California and supplemental Decrees (1979 and 1984). The amounts, priority dates and state where the rights are perfected, are as follows: Amount (afy) Acreage Priority Date State 51,616 7,743 January 9, 1884 California COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-8 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 415 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 A recent Supreme Court decision issued on June 19, 2000 allows the Tribe to proceed with litigation to claim rights to an additional 9,000 acres of irrigable lands. Proving this claim would increase the water rights for the reservation. Water for the Quechan Tribe is diverted from the Colorado River at Imperial Dam and delivered through the Yuma Project Reservation Division-Indian Unit. The Tribe has other small uses at homestead sites south of Yuma, Arizona. The current water uses shown in the following tables include only Quechan Indian Tribe uses within the Fort Yuma Reservation. These uses are accounted for in the CRSS model with one diversion point on the Imperial Dam Diversions reach. The current withdrawal and depletion values have been updated to reflect the most recent consumptive use numbers provided by the LCRAS report for calendar year 1998. Future depletions at full development are calculated as the greater of 70 percent of diversion rights and the per acre rate of consumptive use from the LCRAS report multiplied by the full right acreage of the Tribe. 3.14.2.10 COCOPAH INDIAN TRIBE The Cocopah Indian Reservation is located in southwestern Arizona near Yuma, Arizona. The Tribe possesses present perfected federal reserved wateror eri rights from the main stem of the Colorado River pursuant to the Decree in the Int v. California and Arizona 017 f supplemental Decrees (1979 and 1984). The amounts, priorityrdates, 2 state where pt. o e 29, and De b the rights are perfected, are as follows: tion v. ovem N Na vajo hived on Amount (afy) N Acreage Priority Date in a rc ited 6864, a c 7,681 1 1,206 September 27, 1917 14No. State Arizona 2,026 318 June 24, 1974 Arizona 1,140 190 1915 Arizona 10,847 1,714 Total The rights listed above and in the attached tables include only that water diverted directly from the Colorado River at Imperial Dam. In addition to these rights, the Tribe has numerous well permits that divert groundwater that may be connected to the Colorado River within the boundaries of the United States (studies are ongoing). The 1974 present perfected federal reserved right for the Cocopah Indian Reservation is unique because of its more recent priority date. The 1979 supplemental Decree in Arizona v. California specifies that in the event of a determination of insufficient mainstream water to satisfy present perfected rights pursuant to Article II (B) (3) of the 1964 Decree, the present perfected rights set forth in paragraphs (1) through (5) of Article II (D) of the Decree must be satisfied first. The 1984 supplemental Decree in Arizona v. California recognized the present perfected federal reserved right for the COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-9 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 416 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Cocopah Indian Reservation dated June 24, 1974, and amended paragraph (5) of Article II (D) of the Decree to reflect this 1974 right. The Tribe is involved in litigation to claim rights to a total of 2,400 acres of irrigable lands. Proving this claim would further increase the water rights for the reservation. Water diversions for the Cocopah Indian Tribe are listed at two demand nodes in the CRSS model on two of the model reaches. A demand point on the Imperial Dam diversion reach accounts for all of the Tribe’s rights and current uses in Arizona. Another node is provided for future pumped diversions below Imperial Dam, but it has a diversion of zero af at the current time. Current depletion amounts for the CRSS model nodes have been updated to reflect the most recent consumptive use numbers provided by the LCRAS report for calendar year 1998. Future depletions at full development are assumed to be 100 percent of the diversions as the location of the reservation prevents a return flow within Arizona. 3.14.2.11 ENVIRONMENTAL CONSEQUENCES The Ten Tribes have a significant amount of undeveloped water rights. The current availability of surplus water on the Colorado River is primarily a direct result of unused rior existing entitlements, including those of the Tribes. The Ten e Intehave raised Tribes 17 th significant concerns that interim surplus criteria could: 1)ffoster a 9, 20 on surplus pt. o er 2reliance De b water on the part of other entitlement holders; .2) providemdisincentive for those ion v Nove a at development; and 3) have the practical entitlement holders to support ajo NTribal d on future Nav abilityitoe effect of diminishing the Tribes’ arch v utilize their entitlements. d in cite 16864, The interim surplus 14 No. criteria will not alter the quantity or priority of tribal entitlements. In fact, as noted by the description of the Ten Tribes’ water rights above, the Tribes have the highest priority water rights on the Colorado River. Surplus determinations have been made since 1996. The interim surplus criteria would not make any additional surplus water available as compared with current conditions, but rather would provide more objective criteria for surplus determinations. Moreover, the preferred alternative would quantify the amounts of surplus water to be made available. Reclamation does not believe that identifying the limited amounts of surplus water will provide any additional disincentives for Tribal water development. Interim surplus criteria are intended to assist in the effort to reduce the overreliance by California on surplus water. The selection of any of the alternatives of this proposed action does not preclude any entitlement holder from using its water. 3.14.2.11.1 Upper Basin Mainstem Tribes As expected, the model analyses showed that interim surplus criteria would have no effect on Upper Basin deliveries, including the Tribal demands above Lake Powell. As noted in Section 3.4.4.4, the normal delivery schedules of all Upper Basin diversions would be met under most water supply conditions. Only under periods of low COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-10 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 417 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 hydrologic conditions would an Upper Basin diversion be shorted. Although the model is not presently configured to track the relative priorities under those conditions, such effects are identical under baseline and all alternatives. 3.14.2.11.2 Lower Basin Mainstem Tribes Under normal conditions, deliveries to Lower Basin users are always equal to the normal depletion schedules, including those for the Tribes. Under shortage conditions, only CAP and SNWA share in the shortage until CAP goes to zero (which was not observed in any of the modeling runs done for this EIS). Therefore, the Tribes of the Ten Tribe Partnership in the Lower Basin would receive their scheduled depletion, with the exception of the Cocopah Tribe that has some Arizona Priority 4 water. However, adoption of the interim surplus criteria would not significantly increase the risk of shortages to holders of Arizona Priority 4 water. For example, the modeling analysis indicates that under the preferred alternative, the occurrence of Priority 4 shortages would be approximately four percent greater than under baseline conditions. 3.14.3 TRIBES SERVED BY CENTRAL ARIZONA PROJECT Various Indian tribes and communities in central Arizona have been provided water rior pursuant to CAP contracts by either direct Secretarial actions e Ithrough negotiated or nte 017 f th water rights settlements (CAP Tribes). CAP water has played a primary role in pt. o er 29, 2 . De b facilitating water rights settlements in Arizona; it is expected to play such a role in the ion v Novem at future. In fulfillment of the trust o N o the aj responsibility,n impact of shortages upon the water i primary NavTribeschaved concern. supplies provided to the CAP ar is d in cite 16864, 14The Tribes that receive CAP water are listed below together with the counties in which No. their reservations are located: Gila River Indian Community San Carlos Indian Tribe Tohono O’Odham Nation Tonto Apache Tribe Yavapai-Apache Indian Community Fort McDowell Indian Community Salt River Pima Maricopa Indian Community Ak Chin Indian Community Pascua-Yaqui Tribe Yavapai-Prescott Indian Tribe 3.14.3.1 3.14.3.1.1 Maricopa and Pinal Gila, Pinal and Graham Pina, Maricopa and Pinal Gila Yavapai Maricopa Maricopa Pinal Pima Yavapai WATER RIGHTS SETTING CAP Priority Scheme An understanding of the CAP priority scheme is vital in order to understand how shortages could potentially impact the different priorities of CAP water and CAP water COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-11 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 418 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 users, including Indians. Traditionally, Reclamation’s view is that the CAP has five priorities of water rights. The first priority is known as Colorado River water. Colorado River water was secured by the United States for settlement of certain Indian water claims. The second priority includes M&I water and Indian Homeland water. The third priority is Indian agricultural water that was allocated to tribes by the Secretary but was not classed as Homeland water. The fourth priority is M&I water above the first 510,000 af of the M&I allocation (equal to 128,823 af). The fifth priority is non-Indian agricultural water. The fifth priority is available to several users besides non-Indian agriculture. For example, 312,898 af of fifth priority CAP water, called Excess water, is available to the Central Arizona Groundwater Recharge District (CAGRD) for groundwater recharge, non-Indian agriculture, and the Arizona Water Banking Authority (AWBA) for in-lieu recharge and direct groundwater recharge. The remaining portion of fifth priority CAP water, 51,800 af, is non-Indian agricultural water that is assumed to be allocated to Indian users. The priorities discussed in this section are internal to the CAP and must not be confused with priorities of water entitlements along the mainstream of the Colorado River. The future allocation of CAP water to some CAP priorities is not definitive because of ior In er 17 the dual possibility of finalizing or not finalizing two settlements. tOne settlement is 0 f the entities among the Gila River Indian Community (GRIC),ept. o Arizona9, 2 and the certain r2 e v D United States (GRIC Settlement). The tsecond.settlementmb CAP Settlement a ion on Nove is the between the United States and ajo Centraled the N Arizona Water Conservation District Nav archiv (CAWCD). Under d in shortage, potential impacts to Indian CAP water users differ te 6 c whether CAP 4, is allocated under settlement or without settlement. depending upon i -168 water No. 14 Table 3.14-1 provides, in units of afy, allocations of CAP water to CAP priorities for certain Indian Tribes or communities under two scenarios. The first scenario, Likely Future Without, reflects assignment of water rights absent final GRIC and CAP settlements. The second scenario, With Settlement, assumes final GRIC and CAP settlements. The primary difference between the two scenarios is that with final settlements, GRIC is assigned an additional 102,000 af of non-Indian agricultural water and the United States reserves 69,800 af of other non-Indian water for future water rights settlements. Table 3.14-2 reflects the CAP priority scheme under the two scenarios and identifies the points at which shortages on the Colorado River begin to impact different priorities of CAP water. Normal year diversions of CAP water are assumed to be 1.5 maf. Reductions for system losses result in deliverable water of 1,415,000 af. The effects of shortages on CAP water associated with various priorities is as follows: Fifth Priority. In the event of a shortage on the river restricting deliveries of CAP water to 925,000 af, the fifth priority water rights would go unfulfilled. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-12 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 419 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Table 3.14-1 Central Arizona Project Indian Water Allocations Unit: Acre-Feet Annually Likely Future without GRIC (afy) Indian Tribe and Allocation Gila River Indian Community Indian Allocation Indian Priority – HVID Settlement Water M & I – ASARCO Non-Indian Agric.-RWCD Other Total San Carlos Indian Tribe Indian Allocation M & I Priority Indian Reallocation (Ak Chin)(minus losses) With GRIC Settlement (afy) 17,000 18,600 226,500 17,000 18,600 102,000 328,500 12,700 18,145 30,800 12,700 18,145 30,800 61,645 61,645 45,800 28,200 74,000 45,800 28,200 74,000 128 128 128 128 1,200 25,000 50,000 75,000 25,000 50,000 75,000 500 500 500 500 500 500 500 500 309,828 54,428 255,400 70,900 31,733 35,145 51,800 1,518 498,424 309,828 54,428 255,400 70,900 31,733 35,145 153,800 1,518 69,800 670,224 603,678 312,898 1,415,000 Indian Allocation Total Fort McDowell Indian Community 173,100 17,800 1,200 1,200 Total Tohono O'Odham Nation (San Xavier, Schuk Toak, Chui-Chu) Indian Allocation Non-Indian Agric. Total Tonto Apache Tribe Indian Allocation Total Yavapai-Apache Indian Community 173,100 17,800 603,678 141,098 1,415,000 ior 1,200 Inter 17 the 0 4,300 f 4,300 Indian Allocation pt. o 13,933r 29, 2 13,933 Indian Priority-HVID e v. D mbe Total 18,233 18,233 ation on Nove Salt River Pima Maricopa Indian Community N o Indian Allocation 13,300 13,300 ed avaj Colorado River (net of N 20,900 20,900 in losses)4, archiv d Non-Indian te 5,000 5,000 ci Agric. 1686 Total 439,200 39,200 .1 Ak Chin Indian Community No Indian Allocation Colorado River Total Pascua Yaqui Tribe Indian Allocation Total Yavapai-Prescott Indian Tribe (assigned to Scottsdale) Indian Allocation Total Total Indian Allocations Indian Allocation Homeland Agricultural Colorado River Indian Priority-HVID M & I Priority Non-Indian Agric. Unassigned HVID Future Settlements (agric. priority) Total Municipal and Industrial Water Supply Non-Indian Agricultural Water Supply Total Normal Water Supply Source: Central Arizona Project 1996 Water Supply Study for Stage II Cost Allocation Draft EIS for allocation of CAP water supply -- June, 2000 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-13 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 420 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Fourth Priority. Subsequent reductions would impact M&I water amounts in excess of 510,000 af. Consequently, any M&I priority water which has been reallocated for Indian use would also be affected. Third Priority. The next block of water to be impacted by shortages is a portion of the Indian agricultural water. The deliveries to GRIC would be reduced by 25 percent of its agricultural allocation; all other tribes having Indian agricultural water would be reduced by 10 percent of their respective agricultural allocations. Second Priority. The remaining M&I and Indian priority water would be reduced on a pro rata basis as water deliveries decrease. First Priority. Colorado River water would be unavailable only if a shortage were severe enough that no diversion could be made into central Arizona. 3.14.3.1.2 Examples of Reductions of CAP Water Deliveries Table 3.14-3 demonstrates the incidence of reductions to the CAP Indian supplies during shortage on the Colorado River under the Likely Future Without r scenario. terioto show the Various quantities of CAP water deliveries have been assumed in order 7 he In that represents a varying impacts between Indian tribes. The amountpt. CAP water9, 201 of of t 2 e division between one priority and the nextn v. Dpriority isber higher m referred to here as a “break ve io point.” For example, the estimated Nat point n No the fifth and fourth priorities is ajo break ed o between Nav ar 1,050,302 af. A total available CAPchiv supply of 1,050,302 af means that no d in CAP4waterwater be made. If the shortage decreases the ci e 1 deliveries of fifthtpriority 686 , would available total No. 14 supply below 1,050,302 af, deliveries of fourth priority CAP CAP water water would be impacted. Similarly, between the fourth and third priorities, the break point is 921,479 af. The division between the third and second priority is 869,974 af. Finally, the last break point is 68,400 af. See Section 3.4.4.1.2 for a summary of the Arizona modeled annual depletions under normal, surplus and shortage conditions. Reductions in Indian water supplies in the fifth priority are estimated to be 51,800 af. The affected amount of Indian water supply in the fourth priority is 7,087 af. The third priority Indian agricultural water affected totals 51,505 af. Indian priority water in the second priority totals 317,132 af. Finally, the Colorado River priority water held by Indians totals 68,400 af. Table 3.14-4 shows the same information as Table 3.14-3, but assumes a final GRIC and CAP settlement. The same priority scheme is applied as used in the without settlement scenario. In this instance, GRIC is allocated an additional 102,000 af of nonIndian agricultural water. The amount of 69,800 af of non-Indian agricultural water is held by the United States for future Indian water rights settlements. As a result, the potential Indian/federal loss in the fifth priority increases to 223,600 af, as compared with 51,800 af without settlement. Impacts to the other priorities remain the same. COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-14 Pro rata reduction of Indian and M & I water Second: Likely 801,574 68,400 GRIC Future without Total 68,4001 801,574 869,9742 Indian agricultural water (reduce 25 % of GRIC ag. water, and 10 % of other Indian ag.) 51,505 6 5 4 921,4793 3.14-15 The traditional USBR interpretation of shortage sharing criteria is used in the analysis of the likely future with and without the GRIC settlement. It is understood that new shortage sharing criteria are included in the GRIC settlement but the settlement is under negotiation at the current time. Reclamation believes that the use of the traditional shortage sharing criteria for likely future with GRIC settlement will not have a major effect on the relative difference among the alternatives. GRIC Settlement" amount is the sum of 153,800 af of reallocated agricultural water and 69,800 af of reallocated agricultural water held by U. S. for future Indian water settlements The amount is an estimate of the excess water pool, with and without settlement between the U.S. and CAWCD Likely Future" amount is 51,800 af of reallocated agricultural water Amount is the difference between 638,823 af and 510,000 af of M&I priority water Amount is made up of 43,275 af of GRIC water and 8,230 af of other Indian agricultural water COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 7 6 5 4 3 1,415,000 1,273,902 1,050,302 921,479 869,974 68,400 Water With GRIC Settlement 68,4001 Total Water Notes: 1 The total represents the Yuma Mesa water (50,000 af) plus Wellton-Mohawk water (22,000 af) minus estimated transmission losses. 2 Total is composed of 510,000 af of M&I water plus 33,251 af of HVID water plus 258,323 af of Indian water after reductions in third priority and losses Fifth: Fifth: Fourth: Acre-Feet Per Year ior Inter 17 51,505 e (Indian agric. water is that portion of original allocation which is not "Homeland") of th 29, 20 pt. r . De embe1,050,302 M & I water above 510,000 acre feet, including M&I reallocations to Indiansv 128,823 128,823 n atio on Nov N vajo hived Non-Indian agricultural water reallocated to Indians 51,800 1,102,102 223,600 in Na 4, arc cited 1686 Excess water (priority = 1, CAGRD, 2, Agric., 3 AWBA ) 312,898 1,415,000 141,098 14No. Colorado River Water – Yuma Mesa and Wellton Mohawk First: Third: CHAPTER 3 Table 3.14-2 7 Traditional Reclamation Priorities for Central Arizona Project Water AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 421 of 1200 1 226,500 61,645 74,000 128 1,200 18,233 39,200 75,0001 500 500 ior Inter 17 e of th 29, 20 pt. . De ember v ation on Nov N vajo hived Na d in 64, arc cite 168 o. 14 N 1,518 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-16 Ak-Chin values are not additive because system losses on the 50,000 af of Colorado River Priority water are borne by San Carlos Tribe, except in the instance of CAP deliveries restricted to Colorado River rights only [first priority]. In this case system losses are borne by Ak-Chin. Total Reductions First Priority Colo. River M&I and Indian Second Priority Third Priority Indian Ag. M&I Fourth Priority Agricultural Fifth Priority CHAPTER 3 Accumulated CAP Total Tohono Tonto Yavapai Pascua Yavapai Water Reduction GRIC San Carlos FMIC SRPMIC Ak Chin Unassigned Reductions Reductions O'Odham Apache Apache Yaqui Prescott per Priority Supply HVID 1,415,000 none none none none none none none none none none 115,000 1,300,000 5,865 8,892 1,577 16,334 215,000 1,200,000 10,965 16,625 2,948 30,538 315,000 1,100,000 16,065 24,357 4,319 44,741 364,698 1,050,302 18,600 28,200 5,000 51,800 51,800 50,302 1,000,000 1,339 1,429 2,767 125,302 925,000 3,334 3,559 6,894 128,823 921,479 3,428 3,659 7,087 58,887 21,479 900,000 18,047 1,501 334 555 1,043 21,479 51,505 869,974 43,275 3,600 800 1,330 2,500 51,505 110,392 69,974 800,000 14,072 4,748 3,928 11 105 1,592 1,045 1,964 44 44 133 27,684 169,974 700,000 34,182 11,533 9,542 27 254 3,866 2,538 4,771 106 106 322 67,248 269,974 600,000 54,292 18,317 15,156 43 404 6,141 4,032 7,578 168 168 511 106,812 369,974 500,000 74,402 25,102 20,770 59 554 8,416 5,525 10,385 231 231 701 146,375 469,974 400,000 94,512 31,887 26,384 75 704 10,690 7,018 13,192 293 293 890 185,939 569,974 300,000 114,622 38,672 31,998 91 853 12,965 8,511 15,999 356 356 1,079 225,502 669,974 200,000 134,732 45,457 37,612 107 1,003 15,240 10,005 18,806 418 418 1,269 265,066 769,974 100,000 154,842 52,242 43,226 123 1,153 17,514 11,498 21,613 480 480 1,458 304,630 799,074 68,400 161,197 54,386 45,000 128 1,200 18,233 11,970 22,500 500 500 1,518 317,132 427,524 70,900 0 20,900 47,500 68,400 Table 3.14-3 Reductions in Indian CAP Water Supplies During Times of Shortage on Colorado River Likely Future Without GRIC Settlement AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 422 of 1200 2 1 70,900 799,074 769,974 669,974 569,974 469,974 369,974 269,974 169,974 69,974 51,505 21,479 128,823 125,302 50,302 364,698 315,000 215,000 115,000 Reduction 328,500 161,197 154,842 134,732 114,622 94,512 61,645 54,386 52,242 45,457 38,672 31,887 3,559 1,429 28,200 24,357 16,625 8,892 San Carlos Tohono Tonto Yavapai O'Odham Apache Apache none none none none none FMIC 5,000 4,319 2,948 1,577 none none SRPMIC Ak Chin Pascua Yaqui none 74,000 45,000 43,226 37,612 31,998 26,384 128 128 123 107 91 75 1,200 1,200 1,153 1,003 853 704 18,233 18,233 17,514 15,240 12,965 10,690 39,200 20,900 11,970 11,498 10,005 8,511 7,018 75,0002 47,500 22,500 21,613 18,806 15,999 13,192 500 500 480 418 356 293 500 500 480 418 356 293 1,518 1,518 1,458 1,269 1,079 890 69,800 69,800 60,288 41,149 22,010 68,400 317,132 304,630 265,066 225,502 185,939 146,375 106,812 67,248 27,684 51,505 21,479 7,087 6,894 2,767 223,600 193,130 131,819 70,508 COLORADO RIVER INTERIM SURPLUS CRITERIA FEIS 3.14-17 Ak-Chin values are not additive because system losses on the 50,000 af of Colorado River Priority water are borne by San Carlos Tribe, except in the instance of CAP deliveries restricted to Colorado River rights only [first priority]. In this case system losses are borne by Ak-Chin. 599,324 282,192 230,687 223,600 Accumulated Total Yavapai Unassigned Reserved Reductions Reductions Federal per Priority Prescott HVID none none none ior 3,428 3,659 Inter 17 the 20 18,047 1,501 334 555 t. of 1,043 ep 2,500 ber 29, D 43,275 3,600 800 n v. 1,330 ovem tio N 14,072 4,748 3,928 11 105 44 44 133 jo Na ve1,592on1,045 1,964 a d v 27 hi 3,866 2,538 4,771 106 106 a 34,182 11,533in N 322 d 9,54264, arc 254 ite 54,292c 18,317 15,156 511 68 43 404 6,141 4,032 7,578 168 168 14-1 74,402 o. 701 N 25,102 20,770 59 554 8,416 5,525 10,385 231 231 3,334 1,339 120,600 104,166 71,097 38,029 none GRIC CHAPTER 3 Due to ongoing GRIC negotiations, Reclamation decided to use the traditional USBR interpretation of shortage sharing criteria to compare the relative differences among alternatives. Reclamation believes that the negotiated shortage sharing criteria to be included in the GRIC settlement will not impact the relative differences among alternatives. 0 70,900 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 869,974 900,000 921,479 925,000 1,000,000 1,050,302 1,100,000 1,200,000 1,300,000 1,415,000 First Priority Colo. River Total Reductions M&I and Indian Second Priority Third Priority Indian Ag. M&I Fourth Priority Agricultural Fifth Priority CAP Water Supply 3.14-4 Reductions in Indian CAP Water Supplies During Times of Shortage on Colorado River Likely Future with GRIC Settlement AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 423 of 1200 Case: 14-16864, 12/04/2017, ID: 10675851, DktEntry: 131-2, Page 424 of 1200 AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 Losses of fifth priority water impacts only GRIC, Tohono O’Odham Nation (TON), Salt River Pima Maricopa Indian Community (SRPMIC) and the United States. Fourth priority losses impact only GRIC and the San Carlos Apache Tribe (San Carlos). Third priority Indian agricultural water losses impact GRIC, San Carlos, TON and SRPMIC. If Colorado River shortages reduce CAP deliveries below 869,974 af, thereafter all Indian tribes are affected on a proportional basis, except for SRPMIC and Ak Chin, who have rights to Colorado River water. Tables 3.14-3 and 3.14-4 show reductions within each priority as water supplies diminish for selected delivery and supply scenarios. 3.14.3.2 3.14.3.2.1 ENVIRONMENTAL CONSEQUENCES Impacts Resulting from Baseline Conditions and Alternatives Under the current CAP operational assumptions regarding shortage on the Colorado River, diversions to the CAP are estimated to be restricted to one mafy with deliveries of about 925,000 af. The assumptions and estimated shortages of CAP Indian water deliveries determined in this EIS did not consider implementation of any proposals to provide for firming of the CAP Indian water supply. Should firming programs be developed forior portions of the Inter 17 non-Indian agricultural priori