Draft Environmental Impact Statement Allocation of Water Supply and Long-Term Contract Execution Central Arizona Project JUNE 2000 VOLUME 2 TECHNICAL APPENDICES APPENDIX A BACKGROUND ASSUMPTIONS FOR TECHNICAL ANALYSIS APPENDIX B CAP ALLOCATION HISTORY APPENDIX C FUTURE WATER USES BY MUNICIPALITIES APPENDIX D SOCIOECONOMIC ANALYSIS APPENDIX E BIOLOGICAL TECHNICAL INFORMATION AND DATA SUMMARIES APPENDIX F SCOPING REPORT APPENDIX G CULTURAL RESOURCES OVERVIEW FOR THE PROPOSED CENTRAL ARIZONA PROJECT WATER REALLOCATION PLAN APPENDIX H AIR QUALITY CALCULATIONS APPENDIX A BACKGROUND ASSUMPTIONS FOR TECHNICAL ANALYSIS Draft Environmental Impact Statement Allocation of Water Supply and Long-Term Contract Execution Central Arizona Project Central Arizona Project Allocation Administrative Draft Environmental Impact Statement Appendix A – Background Assumptions Table of Contents Page # I. INTRODUCTION A-1 II. LIST OF KEY ASSUMPTIONS A-3 A. CAP Diversions and Available Colorado River Water A-3 B. Water Priorities A-4 C. Indian Development Schedule and Water Use A-5 D. M&I Development Schedule and Water Use A-5 E. M&I Leases A-6 F. CAGRD and Interim Contracts A-6 G. Recharge Pool A-6 H. Ag Pool A-7 I. NIA Sub-Contractors Under Non-Settlement Alternative 3A A-7 III. DISCUSSION OF KEY ASSUMPTIONS A-8 A. CAP Diversions A-8 B. Shortage A-8 C. Surplus A-9 D. CAP Deliveries A-9 E. Water Priority A-10 F. Indian Development Schedule and Water Use A-10 G. M&I Development Schedules and Water Use A-11 H. M&I Leases of Indian Water A-12 I. CAGRD and Interim Contracts A-13 J. Recharge Pool A-13 K. Ag Pool A-14 L. Contracted NIA Water A-15 M. NIA Entities A-17 IV. ALTERNATIVES IN THE DRAFT EIS A-17 A. No Action Alternative and Non-Settlement Alternatives 1, 2, and 3 A-18 1. Key Assumptions A-18 B. Settlement Alternative A-19 LIST OF FIGURES LIST OF TABLES APPENDIX A List of Figures Figure No. Description Page # A-1 Projected CAP Water Supply Deliveries A-35 A-2 Settlement Alternative-Full CAP Water Supply Distribution A-36 A-3 No Action-Full CAP Water Supply Distribution A-37 A-4 Settlement Alternative-Distribution of CAP Water Deliveries A-38 A-5 No Action-Distribution of CAP Water Deliveries A-39 A-6 Alternative 1-Distribution of CAP Water Deliveries A-40 A-7 Alternative 2-Distribution of CAP Water Deliveries A-41 A-8 Alternative 3A-Distribution of CAP Water Deliveries A-42 A-9 Alternative 3B-Distribution of CAP Water Deliveries A-43 A-10 Indian Build Out-On Reservation Use by Alternative A-44 APPENDIX A List of Tables Table No. Description Page # A-1 Settlement Alternative Indian Leases by Alternative A-21 A-2 Projected Direct and In-Lieu Recharge Pattern, 2001-2051 A-22 A-3 Settlement Alternative Distribution of CAP Supply A-23 A-4 No Action Alternative Distribution of CAP Supply A-24 A-5 Non-Settlement Alternative 1-Distribution of CAP Deliveries by Category A-25 A-6 Non-Settlement Alternative 2-CAP Deliveries by Category A-26 A-7 Non-Settlement Alternative 3A-CAP Deliveries by Category A-27 A-8 Non-Settlement Alternative 3B-CAP Deliveries by Category A-28 A-9 M&I Population Projections and Projected Demands A-29 A-10 Preliminary Summary of M&I Entities at 2051 A-30 A-11 CAP Ag Pool Percentage Distribution A-31 A-12 Non-Settlement Alternative 3A NIA Allocation A-32 A-13 Summary of Key Assumptions Affecting NIA Sector A-33 A-14 Summary of Key Assumptions Affecting Indian Sector A-33 A-15 Summary of Key Assumptions Affecting M&I Sector A-34 A-16 Summary of Key Assumptions Affecting AWBA and CAGRD A-34 APPENDIX A BACKGROUND ASSUMPTIONS A.I. INTRODUCTION In order to describe and evaluate the anticipated environmental consequences of implementing any of the action alternatives considered in the draft Environmental Impact Statement (EIS), it is first necessary to identify questions whose “answers” are critical to performing the necessary impact analyses. These questions include key issues such as, “What would water use patterns be in Arizona for the next fifty years?” “Would farmers be able to afford Central Arizona Project (CAP) water and how much of it would be available?” “How would municipal and industrial (M&I) entities meet their projected populations’ water demands?” and “What would the Indians do with the water proposed to be allocated to them?” Since “answers” for these types of questions are not available, it falls to the technical and professional staff to develop assumptions about what are the most likely outcomes based upon past, current and projected practices. Fundamental to the development of the background assumptions used in the impact analyses conducted for the “Allocation of Water Supply and Expected Long-Term Contract Execution – CAP EIS” is an understanding of the conditions and policies that exist and are expected to exist throughout the project period (2001-2051). These conditions and policies determine, to a great extent, the distribution and use of CAP water supplies by the three primary CAP water use sectors. The assumptions are primarily related to the availability and pricing of CAP water for the project period. They are referred to as “background assumptions” because they help determine each affected entity’s water budget, which, in turn, drives the impact analyses. The assumptions were developed based upon input from Navigant Consulting, Inc., the Bureau of Reclamation (Reclamation) Phoenix Area and Lower Colorado Regional offices, the Department of the Interior Solicitor’s Office, Arizona Department of Water Resources (ADWR), Central Arizona Water Conservation District (CAWCD), Central Arizona Groundwater Replenishment District (CAGRD), Arizona Water Banking Authority (AWBA), and others. This appendix identifies the background assumptions that were developed to establish the inputs for the impact analyses as well as for the groundwater and socioeconomic evaluations. The assumptions are based on existing water management policy, available information, and discussions with representatives of water users and involved institutions and entities. Assumptions made for each particular impact analysis are noted in the appropriate technical appendices. This appendix documents only the background assumptions common to all analyses. Every analysis contains assumptions through which the accuracy of the results should be viewed, and this Draft EIS is no exception. It is likely that the assumptions involved in the Draft EIS may be as important to the outcome of the impact analyses as the analyses themselves. The analysis of the potential impacts to the NIA sector is a good example. If the assumption is made that competitively-priced CAP water would be available in today’s volumes and prices to non-Indian agriculture (NIA) for the entire 50-year project period, very different impacts would emerge than if the assumption is made that CAP water for NIA is not available due to increased demand by other users in the early years. A-1 APPENDIX A CAP ALLOCATION DRAFT EIS BACKGROUND ASSUMPTIONS Careful consideration was given to the ramifications of CAP water availability to the various sectors. In developing the assumptions, an effort was made to forecast what policies would be put in place under each alternative evaluated in the Draft EIS, based upon a thorough analysis of currently available information. Sensitivity was also given to avoid skewing the impacts in any sector through the background assumptions. In particular, great care was taken in developing the assumptions for the No Action Alternative in an effort to provide a fair baseline against which the impacts of the other alternatives would be evaluated. It should be noted that the future may likely diverge from the Draft EIS background assumption projections, and it is entirely possible other actions would occur. These other actions could include the adoption of a wheeling policy for CAP, settlement of additional Indian water right claims, and other actions that cannot be predicted. They are not included in the Draft EIS analysis, as their outcomes and timing would be pure speculation. While it is likely the future would not look exactly like any of the projections made in this Draft EIS, this analysis reflects the most reasonably expected future scenarios, based upon information available at the time of this analysis. The assumptions are consistent with the existing legal and institutional constraints that include the following: ♦ Federal Reclamation Law • Act of June 17, 1902, as amended and supplemented; • Boulder Canyon Project Act of 1928 (Public Law[PL] 70-642); • Reclamation Project Act of 1939, as amended; and • Colorado River Basin Project Act of 1968 (PL 90-537). ♦ Indian Water Rights Settlement Acts • Southern Arizona Water Rights Settlement Act of 1982 (PL 97-293); • Ak-Chin Indian Community Water Rights Settlement Act of 1984 (as amended) (PL 98-530); • Salt River Pima-Maricopa Indian Community (SRPMIC) Water Rights Settlement Act of 1988 (PL 100-512); • Fort McDowell Indian Community (FMIC) Water Rights Settlement Act of 1990 (PL 101-628); • San Carlos (SC) Apache Tribe Water Rights Settlement Act of 1992 (as amended) (PL 102-575); and • Yavapai-Prescott Indian Tribe Water Rights Settlement Act of 1994 (PL 103-434). ♦ Secretary of the Interior Decisions and Actions • 1980 Indian Contracts; • 1983 Record of Decision (ROD) CAP Allocation; • 1988 CAP Master Repayment Contract; and • 1992 Federal Register (FR) Notice (NIA Allocation) A-2 APPENDIX A CAP ALLOCATION DRAFT EIS BACKGROUND ASSUMPTIONS ♦ Arizona State Law and Regulations • Groundwater Management Act (GMA); • Assured Water Supply (AWS) Rules; • CAGRD Laws; • AWBA Laws; and • Recharge Permit/Accounting Laws. The key assumptions are listed below. Detailed discussions of each category of assumptions are included after the list of key assumptions. Descriptions of the assumptions per each alternative are included following the discussion.