Reclamation Publishes Final Environmental Impact Statement for Future Colorado River Operations

WASHINGTON — The Bureau of Reclamation has released the Final Environmental Impact Statement, which designates a preferred course of action for future management of Lake Powell and Lake Mead. The preferred alternative establishes an adaptive decision framework to be used to develop operating guidelines designed to ensure reliable operations in the Colorado River Basin while maintaining the flexibility to respond to changing conditions over a 10-year period through 2036. The framework also preserves the opportunity for the Basin to continue working towards consensus agreements, and if successful, be incorporated into future operations.

The framework will be used to develop operating guidelines for operations at Lake Powell and Lake Mead that can be adjusted for shorter and longer term periods.

“The Department has a responsibility to ensure the Colorado River system remains reliable and resilient for the millions of Americans, communities and industries that depend on it," said Secretary of the Interior Doug Burgum. "This framework provides the flexibility to respond to changing hydrologic conditions while preserving the opportunity for the Basin States to continue working toward durable, consensus-based solutions.”

The framework establishes the operational principles, sideboards—key thresholds and ranges for operational elements—and a process that will govern development and issuance of operating guidelines through 2036. Operational sideboards were chosen to ensure that the Department would have flexibility and environmental compliance to operate the system in a way that is responsive to actual hydrologic conditions and allows for the incorporation of Basin-wide innovative water management solutions. The sideboards, which are analyzed in the Final EIS, provide for annual releases from Lake Powell between 5.0 maf and 12.0 maf, Lower Basin shortages of up to 3.0 maf, the ability to store up to 8.0 maf and 3.0 maf of conserved water in Lake Powell and Lake Mead for future use, respectively, and the opportunity for voluntary Upper Basin conservation up to 200 kaf, subject to hydrology.

The Department would issue operating guidelines, within these sideboards, at anticipated 2-year periods, unless consensus-based agreements provide for a longer duration. It also establishes a structure under which operating guidelines will be developed, reviewed and periodically updated. This approach provides certainty regarding a decision process over the next 10 years while preserving the flexibility to adapt to changing conditions.

“This plan strikes a balance between flexibility and predictability for the Colorado River system that is vital to the 40 million people who rely on it given unprecedented hydrologic conditions and the potential for considerable impacts on water users,” said Assistant Secretary for Water and Science Andrea Travnicek. “It also allows a new flexibility to respond to changing conditions and potential consensus.”

The Colorado River provides water for more than 40 million people and fuels hydropower resources in seven states. It serves as a vital resource for 30 tribes and two Mexican states, sustaining 5.5 million acres of farmland and agricultural communities throughout the West, while also supporting critical ecosystems and protecting endangered species.

Drought conditions over the past 25 years, combined with expectations of continued dry conditions, have made development of future operating guidelines for the Colorado River particularly challenging. The combined contents of Lake Powell and Lake Mead have not been this low since before Glen Canyon Dam began filling in 1963, and since 2000 water use has exceeded total system inflow in most years. The Colorado River Compact apportioned 7.5 million acre-feet to both the Upper and Lower Basins based on the estimated pre-compact average inflow (1906-1921) of approximately 18 million acre-feet. However, inflows from 2000 to 2024 have only averaged 12.9 million acre-feet and the unregulated inflow into Lake Powell this year as of July is estimated to be only 3.5 maf.

Between 2020 and 2024, the average consumptive use in the Colorado River Basin was 13.1 million acre-feet. That is broken down by:

• Upper Basin Use: 3.8 million acre-feet (29%).
• Lower Basin Use: 6.5 million acre-feet (49%).
• Mexico Use: 1.4 million acre-feet (11%).
• Evaporation: 1.4 million acre-feet (11%).

This Final EIS is the culmination of a NEPA process that was initiated in June 2023. Over this three-year period Reclamation engaged extensively with Basin stakeholders and that input is reflected in the alternatives analyzed in the Final EIS and the Preferred Alternative.

Reclamation received more than 18,000 comments, including 785 unique submissions from the public, tribes, states, federal agencies and others after releasing the draft EIS in January 2026. Reclamation evaluated substantive comments and updated the final EIS, with public input helping to shape the preferred alternative.

The final EIS addresses only domestic river operations. A separate binational process addressing water deliveries to Mexico is nearing completion and the Department is committed to continued collaboration with Mexico. The Department will conduct all necessary and appropriate discussions regarding post-2026 operations and implementation of the 1944 Water Treaty with Mexico through the International Boundary and Water Commission in consultation with the Department of State. 

##