US Proposes Cutting Colorado River Water Allocations for Three Western States

The US Bureau of Reclamation on April 17 announced a proposal to cut Colorado River water consumption for Arizona, California, and Nevada, aiming to curb the escalating crisis on the river.

The proposal seeks to provide flexibility, allowing deeper cuts during dry periods while giving states more time to reach agreements on managing the dwindling water supply that powers hydroelectric dams.

Under the plan, the three lower-basin states could face reductions of up to 3 million acre-feet (about 3.7 billion cubic meters) annually through 2036. That amount is nearly equal to the combined current allocations for Arizona and Nevada and sufficient to supply more than 25 million people for a year.

The actual reduction levels would be determined every two years based on basin water conditions. The three states would share half of the reduction obligations according to a plan they jointly developed, with the remainder taking into account pre-existing water priority rights.

Meanwhile, the four upper-basin states—Colorado, New Mexico, Utah, and Wyoming—would not face mandatory cuts during this period but could voluntarily reduce usage, mainly in agriculture.

US Interior Secretary Doug Burgum stated: “The Department has a responsibility to ensure the Colorado River system remains stable and resilient for the millions of Americans, communities, and industries that depend on it.”

The Colorado River, stretching over 2,300 kilometers, supplies water to more than 40 million people in seven US states, numerous Native American tribes, and Mexico. Decades of overuse, combined with climate change and drought, have left the river unable to meet the commitments made in 1922.

Water levels at Lake Mead and Lake Powell, the nation's two largest reservoirs, are at historic lows and nearing the point where hydroelectric generation is no longer feasible. Lake Mead, the largest US reservoir on the Colorado River, spans Nevada and Arizona, while Lake Powell is a key reservoir on the river in Utah and Arizona.

In response, Arizona officials—who hold the lowest priority in the lower basin—called the proposal “flawed.” California viewed it as an important milestone but not the final destination. Nevada's governor described the proposed cuts as “unrealistic and devastating.”

The lower-basin states had previously urged all seven states to share specific reductions, but upper-basin states repeatedly rejected this, arguing it was illegal and that they had adapted to the river's available supply.

Governors of the four upper-basin states gave an initially positive assessment but said they were still reviewing the document. In a joint statement, they said: “We are encouraged that the new operating guidelines will better reflect current water supply, which must be the foundation for any viable plan going forward.”

Arizona's Department of Water Resources said a 3 million acre-foot cut in the lower basin would severely impact water users and the state's economy. The Central Arizona Project, which manages much of the state's water for the Phoenix and Tucson metro areas, also argued the proposal does not accurately reflect Arizona's interests.

Experts warn the cuts could lead to higher water prices, increased reliance on groundwater, and fallowed farmland. Farmers in Southern California and Yuma, Arizona—which produces most of North America's winter leafy greens—could be especially hard hit.

Water law professor Rhett Larson of Arizona State University said Phoenix metro cities are not entirely dependent on Colorado River water and can still ensure supply, but prices may rise in some areas. He cited Gilbert, which raised residential water rates by 50% since April 2025. “We're not running out of water; we're running out of cheap water,” Larson said.

The proposal follows years of stalled negotiations among states, with the risk of lawsuits if the plan fails to comply with long-standing river management rules that expire at the end of 2026. The federal government expects to finalize binding operating guidelines by October 1.