The U.S. Department of the Interior announced Friday that it will require the Lower Basin states of California, Arizona and Nevada to reduce their Colorado River water use by a combined 1.25 million acre-feet per year in 2027 and 2028.

The decision largely follows a proposal put forward by the three states themselves and avoids the steeper mandatory cuts of up to 3 million acre-feet annually that the department's broader 10-year framework had outlined as a possibility if reservoir levels continue to fall.

Under the specific allocations tied to the states' sharing agreement, Arizona faces the largest reduction at 760,000 acre-feet per year. California will cut 440,000 acre-feet annually, and Nevada will reduce its use by 50,000 acre-feet each year. The states have also committed to voluntarily conserving and storing an additional 700,000 acre-feet over the two-year period.

The move comes as Lake Mead and Lake Powell sit at their lowest recorded levels. The combined storage in the two reservoirs has not been this low since before Lake Powell began filling in 1963.

The Trump administration's plan spares the Upper Basin states of Colorado, Utah, New Mexico and Wyoming from any mandatory cuts over the next two years. Federal officials noted that different legal authorities apply to the upstream and downstream regions.

Interior Secretary Doug Burgum signed the 2027-2028 Operating Guidelines and the Record of Decision for the Post-2026 Colorado River Operations. The short-term plan provides objective criteria for releases from Lake Powell to maintain a minimum elevation of 3,510 feet.

The 10-year Decision Framework leaves room for adjustments in later years based on actual hydrology and allows continued negotiations among the seven basin states. Officials described the approach as flexible and responsive to conditions while incorporating voluntary conservation measures.