Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead – Draft Environmental Impact Statement

Reclamation has released the Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead – Draft Environmental Impact Statement. A Notice of Availability of the Draft EIS will be published in the Federal Register on January 16, 2026, starting a 45-day public review and comment period.

Executive Summary (7.8 MB, PDF)

Volume 1 – Main Body

• Cover, Abstract, Table of Contents, and Acronyms (2.72 MB, PDF)
• Chapter 1 - Purpose and Need (2.6 MB, PDF)
• Chapter 2 - Description of Alternatives (943 KB, PDF)
• Chapter 3 - Affected Environment and Environmental Consequences (5 MB, PDF)
• Chapter 4 - Consultation and Coordination (228 KB, PDF)
• Preparers, References, Glossary, and Index (738 KB, PDF)

Volume 2 – Supporting Appendices

• Cover, Table Of Contents (713 KB, PDF)
• A. CRSS Model Documentation (3.6 MB, PDF)
• B. Modeling Assumptions: Lake Powell and Lake Mead Storage and Delivery of Conserved Water (805 KB, PDF)
• C. Shortage Allocation Model and Alternative Distribution Model Documentation (5.8 MB, PDF)
• D. Sensitivity Analysis - Effects of Natural Flow Percentage Used for the Supply Driven Alternative (522 KB, PDF)
• E. DMDU Overview and Approach (353 KB, PDF)
• F. Approach to Hydrologic Uncertainty (1 MB, PDF)
• G. CRSS Initial Conditions (826 KB, PDF)
• H. Sensitivity Analysis - Effects of Demand Schedule Assumptions on Modeled Unused Tribal Water Available for Storage in the Enhanced Coordination Alternative (546 KB, PDF)
• I. Sensitivity Analysis – Effects of Alternate Upper Basin Demand Scenarios on Operations at Lake Powell and Lake Mead (5.5 MB, PDF)
• J. Sensitivity Analysis - Effects of Assumed Parameter Values on 602(a) Storage (353 KB, PDF)
• K. Sensitivity Analysis - Effects of Modeling Assumptions with Regard to Future Water Deliveries to Mexico (871 KB, PDF)
• L. Upper Basin States Depletion Schedules (217 KB, PDF)
• M. International Border Region of the Colorado River (4.6 MB, PDF)
• N. Lower Division States Depletion Schedules (872 KB, PDF)
• O. Analysis of Powell Infrastructure Protection Releases (547 KB, PDF)

Volume 3 – Technical Appendices

• Cover, Table of Contents (680 KB, PDF)
• TA-3: Hydrologic Resources (6.6 MB, PDF)
• TA-4: Water Deliveries (4.9 KB, PDF)
• TA-5: Geomorphology and Sediment (2.3 MB, PDF)
• TA-6: Water Quality (1.9 MB, PDF)
• TA-7: Air Quality  (3.3 MB, PDF)
• TA-8: Fish and Aquatic Resources (10.4 MB, PDF)
• TA-9: Vegetation (3.4 MB, PDF)
• TA-10: Terrestrial Wildlife (900 KB, PDF)
• TA-11: Cultural Resources (1.3 MB, PDF)
• TA-12: Paleontological Resources (20 MB, PDF)
• TA-13: Tribal Resource (400 KB, PDF)
• TA-14: Recreation (1.1 MB, PDF)
• TA-15: Dams and Electrical Power Resources (4.1 MB, PDF)
• TA-16: Socioeconomics (3.1 MB, PDF)
• TA 17: Population and Land Use (1.7 MB, PDF)
• TA 18: Indian Trust Assets (3.9 MB, PDF)
• TA 19: Visual Resources (1 MB, PDF)