The Department of the Interior has issued its 2027-2028 Operating Guidelines and Record of Decision for post-2026 Colorado River operations, establishing a 10-year decision framework to stabilize the river system, protect critical dam infrastructure, and mandate significant water delivery cuts across the West. Driven by a 26-year multidecadal drought and record-low winter snowpack during 2025-2026, the combined storage of Lake Powell and Lake Mead has fallen to its lowest point since Lake Powell began filling behind Glen Canyon Dam in 1963.

The new guidelines impose immediate delivery reductions totaling 1.25 million acre-feet annually for Lower Basin states over each of the next two years. Under the state-level breakdown, Arizona faces a 760,000 acre-foot annual reduction, California will absorb a 440,000 acre-foot cut, and Nevada will see a reduction of 50,000 acre-feet per year. Beyond these mandatory cuts, Lower Basin states will voluntarily conserve and store at least 700,000 acre-feet over the two-year period to protect the overall system. Additionally, the framework establishes a federally managed pool to help meet tribal firming obligations and offset delivery impacts on indigenous communities.

“We are grateful for the Seven Basin States, the thirty Basin Tribes, Mexico, and many other basin stakeholders who have provided the feedback and voluntary arrangements necessary for the development of the 2027-2028 Operating Guidelines,” Interior Secretary Doug Burgum stated, noting that 40 million people, millions of agricultural acres, and major western metropolitan areas depend on the river system.

According to the Bureau of Reclamation’s August 2026 24-Month Study, Lake Powell will begin the October 1 water year between 3,510 and 3,540 feet in elevation, placing operations in the Lower Elevation Infrastructure Protection Range. Reclamation plans an initial water year release between 6.0 and 7.0 million acre-feet to maintain a minimum elevation of 3,510 feet required for operational reliability at Glen Canyon Dam, with final release volumes determined in April 2027. Meanwhile, Upper Basin states will coordinate operations across upper storage units—including the Aspinall, Flaming Gorge, and Navajo reservoirs—to protect Glen Canyon Dam infrastructure.

“These decisions provide a water management strategy for Basin stakeholders to respond to the prolonged drought by incorporating flexible tools and voluntary actions while leaving room for consensus agreements,” said Assistant Secretary for Water and Science Andrea Travnicek, emphasizing continued federal collaboration on infrastructure modernization and conservation programs.

Federal Funding and International Coordination

Federal investments in Lower Basin water storage, distribution, treatment, and efficiency projects have exceeded $3 billion since January 2025. The administration is currently reviewing state proposals for additional funding through federal cost-share programs and Working Families Tax Cuts funds for advanced water treatment, desalination, and infrastructure optimization.

A separate binational process addressing water deliveries to Mexico under the 1944 Water Treaty is nearing completion and will be finalized through the International Boundary and Water Commission in consultation with the U.S. Department of State.