Federal government orders steep Colorado River water cuts for Arizona, California and Nevada

With the two largest reservoirs in the nation struggling with record-low water levels and the Colorado River, which feeds them, facing years of drought amplified by climate change, the federal government had hoped that the seven states that draw water from the river could reach an agreement on how to divvy up the shrinking supply.

After they failed to do so, the U.S. Department of the Interior (DOI) stepped in. On Friday, the agency ordered steep cuts to the amount of Colorado River water that will be delivered to California, Nevada and Arizona.

The DOI announced it would reduce the delivery of 1.25 million acre-feet of water each year for the next two years, beginning in 2027, to the Lower Basin states of the West. They also warned that they could order additional cuts over the next 10 years.

While the federal government is mandating the overall reduction, how it's to be divided among the three affected states is based on a voluntary agreement negotiated by those states in May. If the states implement the agreement, Arizona would see a reduction of 760,000 acre-feet, California would face a reduction of 440,000 acre-feet and Nevada would lose 50,000 acre-feet.

The DOI's operating guidelines also encourage the three states to "voluntarily conserve and store at least 700,000 acre-feet of water over the two-year period to protect the system, in addition to the 1.25 million acre-feet per year of reductions."

While the cuts are considerable, they are better than the worst-case scenario the federal government proposed in July, when it suggested the Lower Basin could face up to 3 million acre-feet of cuts per year. Additional reductions are still possible, depending on the hydrology.

"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," said Secretary of the Interior Doug Burgum in a statement. "Forty million people, millions of acres of farmland and ranchland, industries that power the American West, and some of our nation's fastest growing metropolitan areas depend on the Colorado River."

In addition to the reductions, DOI says it will try to keep Lake Powell at or above 3,510 feet, 20 feet above the point at which Glen Canyon Dam could no longer generate hydropower.

The agency didn't mandate reductions to the Upper Basin states, including Colorado, Utah, Wyoming and New Mexico, as it doesn't have the same legal authority over the upper part of the Colorado River. But it is asking those states to agree to operate the Flaming Gorge, Navajo and Aspinall reservoirs in order to send water down and protect Glen Canyon Dam.

"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 Andrea Travnicek, Interior's Assistant Secretary of Water and Science, in a statement.

"The Department and Reclamation will continue to work with all Basin stakeholders to identify areas to maximize efforts throughout the Basin to modernize infrastructure, develop conservation programs, and identify innovative approaches to deliver water under changing conditions," the statement added.