Clark Fork and Kootenai River Basins Water Plan
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CLARK FORK & KOOTENAI RIVER BASINS WATER PLAN—DECEMBER 2014 Contents I. Executive Summary ................................................................................................................. 1 A. Basin Advisory Councils and The Montana Water Supply Initiative (MWSI) ........................................ 2 B. Major Findings of the Clark Fork/Kootenai Scoping Process ................................................................. 4 C. Recommendations from the Clark Fork and Kootenai BAC .................................................................. 5 D. Water User Profile ................................................................................................................................. 9 II. Introduction ......................................................................................................................... 11 A. Statutory Authority for Water Planning .............................................................................................. 11 B. History of Water Planning in MT ......................................................................................................... 12 C. Methodology for Developing the Clark Fork/Kootenai Basins Water Plan ......................................... 15 III. Basin Profile of the Clark Fork and Kootenai Basin ................................................................. 21 A. Socioeconomic Portait – Clark Fork / Kootenai River Basins ............................................................... 21 B. Water User Profile ............................................................................................................................... 28 C. Environmental Concerns ..................................................................................................................... 30 IV. Water Resources in the Clark Fork and Kootenai Basins ......................................................... 32 A. Physical Setting .................................................................................................................................... 32 B. Surface Water Resources of the Clark Fork and Kootenai Basins ....................................................... 42 C. Groundwater Resources of the Clark Fork and Kootenai Basins ......................................................... 56 V. Water Use in the Clark Fork and Kootenai Basins ................................................................... 64 A. Inventory of Consumptive Water Use in the Clark Fork and Kootenai Basins .................................... 64 B. Inventory of Non-Consumptive Water Use in the Clark Fork and Kootenai Basins ............................ 80 C. Existing Water Quality Impairments in the Clark Fork and Kootenai Basins ....................................... 92 VI. Administration ...................................................................................................................... 97 A. Institutional and Legal Framework for Water Use in Montana .......................................................... 97 B. Federal Agencies with a Role in Managing Montana’s Water Resources ......................................... 103 C. State Agencies with a Role in Managing Montana’s Water Resources ............................................. 104 D. Local Government and Non-Governmental Organizations with a Role in Managing Montana’s Water Resources ............................................................................................................................... 105 E. Federal and Tribal Reserved Water Rights ........................................................................................ 106 CLARK FORK & KOOTENAI RIVER BASINS WATER PLAN 2014 i VII. Potential Future Demands for Water in the Clark Fork and Kootenai Basins .......................... 110 A. Demand Projections ……………………………….……………………………………………………………………………………110 B. Climate Variability and Drought in the Clark Fork and Kootenai Basins ………………………………………..117 VIII. Options for Meeting New Water Demands – Opportunities, Strategies and Tools ..................... 134 A. Basins with Unallocated Water ......................................................................................................... 134 B. Change of Use Authorizations ........................................................................................................... 136 C. Mitigation .......................................................................................................................................... 137 D. Current Reservoir Storage ................................................................................................................. 138 E. Basins with Hydrology That Could Potentially Support New Storage ............................................... 139 IX. Major Findings and Key Recommendations.......................................................................... 144 A. Maintaining Water Availability .......................................................................................................... 144 B. Ensuring Natural Systems Health ...................................................................................................... 147 C. Water Rights Administration, Protection and Enforcement ............................................................. 149 D. Meeting Future Water Demand ........................................................................................................ 150 E. Use of Water User Councils for Implementation of the State Water Plan ....................................... 152 X. Glossary of Terms ............................................................................................................... 155 XI. References .......................................................................................................................... 160 XII. List of Figures ...................................................................................................................... 162 XIII. List of Tables ....................................................................................................................... 164 Appendices Appendix I-1 CF-K Final Recommendations Development Report Appendix II-1 2004 Clark Fork Plan Status Report Appendix III-1 Socioeconomic Portrait -Clark Fork-Kootenai Appendix IV-1 Water Resources Appendix V-1 Water Use Methods Appendix V-2 Water Use Non-Consumptive Appendix VII-1 Future Demands & Climate Variability CLARK FORK & KOOTENAI RIVER BASINS WATER PLAN—2014 ii I. Executive Summary In 2013, under direction from the Montana Legislature, the DNRC launched the Montana Water Supply Initiative (MWSI) to work with citizens and community leaders to transform the current Montana State Water Plan into a dynamic guide to help residents and water managers in the state’s major river basins: the Clark Fork and Kootenai, Yellowstone, Upper Missouri, and Lower Missouri. The Legislature directed DNRC to update the State Water Plan and submit the results to the 2015 Legislative Session. The state water plan is to include: • An inventory of consumptive and nonconsumptive uses with existing water rights; • An estimate of the amount of surface and ground water to satisfy new future demands; • Analysis of the effects of frequent drought and new or increased depletions on the availability of future water supplies; • Proposals for the best means, to satisfy existing water rights and new water demands; • Possible sources of water to meet the needs of the state, and • Any legislation necessary to address water resource concerns. During the 18-month long planning process, DNRC worked with the Clark Fork Task Force on developing a basin specific response to each of the subject areas listed above. Results of this effort along with supporting data are contained in this report. The Clark Fork / Kootenai Basins Water Plan serves as a standalone document for guiding the development and management of the basins’ water resources. This basin plan will continue to evolve to meet the planning needs of the two basins. Water use in the Clark Fork and Kootenai River Basins totals approximately 35 million acre-feet annually. Water use in the basin exceeds the amount of water produced annually due to the re-use of water by several hydropower facilities. Hydroelectric power generation accounts for 33 million acre-feet or 94% of the water used in the basins. Approximately 668,782 acre-feet is consumed in the Clark Fork and Kootenai River Basins. Agriculture consumes approximately 448,700 on acre-feet, reservoir evaporation consumes 181,900 acre-feet, and municipal, industrial, domestic, and livestock watering consumes 38,212 acre-feet combined. Demand for water is a function of many factors that are inherently uncertain. Population may grow or decline and agriculture and industry may demand more water or make do with less through greater efficiency. Changing and variable climatic conditions compound this uncertainty. To forecast the potential effects of climate trends on future water supplies in Montana, DNRC modeled a range of climate scenarios following general procedures similar to those described in the U.S. Bureau of Reclamation (2011) West-Wide Climate Risk Assessments. Virtually all model simulations project warmer temperatures and most project modest precipitation increases. Although annual stream flow volumes are expected to stay the same or increase, Montanans are likely to see shift in the timing of runoff do to earlier snowmelt and an increase in the rain