The Interior Department’s 2027-28 rules would cut California’s Colorado River water by 440,000 acre-feet a year if Arizona, California and Nevada sign an agreement to divide the reductions, and with nine weeks to go that agreement has not been finalized.
The federal rules that will govern the Colorado River for the next two years are already on the books. What California’s water agencies still do not have, nine weeks before the cuts begin, is the three-state agreement that determines how much of the reduction lands on them.
Interior Secretary Doug Burgum signed the 2027-2028 Operating Guidelines and a record of decision on Aug. 21, after the seven basin states missed a series of deadlines to reach their own consensus. The guidelines reduce deliveries to the Lower Basin, Arizona, California and Nevada, by 1.25 million acre-feet in each of the next two years. If the three states carry out the sharing agreement they proposed, California’s annual apportionment would fall from 4.4 million acre-feet to 3.96 million, a cut of 440,000 acre-feet. Arizona would lose 760,000 acre-feet and Nevada 50,000.
The department presented the plan as a way to protect the system’s two big reservoirs while leaving the door open to the states. “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,” Mr. Burgum said in announcing the decision, thanking the basin states, the 30 basin tribes and Mexico for “the feedback and voluntary arrangements necessary” to write it.
Andrea Travnicek, the assistant secretary for water and science, said the decisions give stakeholders “flexible tools and voluntary actions while leaving room for consensus agreements.”
Why the deal matters for California
The state-by-state numbers in the guidelines are conditional. According to the operating guidelines, the 440,000-acre-foot figure applies “in accordance with” a Lower Basin implementing agreement. If that agreement is not executed, the secretary will determine each state’s delivery under applicable law.
The agreement also decides the fate of a tool California’s agencies have leaned on for years. Under a 2007 program, water users can leave conserved water in Lake Mead, known as intentionally created surplus, and draw it later. The new guidelines say that if the Lower Basin states do not reach agreement, water stored through Dec. 31, 2026 will still be delivered under the old rules, but “no new ICS may be created after December 31, 2026.”
That provision matters most to the Metropolitan Water District of Southern California, which serves about 19 million people, and the Imperial Irrigation District, the river’s largest single user. At a Senate Energy and Natural Resources Committee hearing on June 10, Sen. Alex Padilla, a California Democrat on the committee, noted that California has banked more than 1.6 million acre-feet in Lake Mead and argued that continued access to that water is essential for the state, which he said should not be penalized for having conserved.
The guidelines also call on the Lower Basin states to voluntarily conserve at least 700,000 additional acre-feet over the two-year period, on top of the mandatory reductions.
Where the agreement stands
On Oct. 1, the first day of the federal water year, Arizona’s top negotiator, Tom Buschatzke, told KJZZ that Arizona and Nevada had their plans in place and that California was “working out final details” on how to spread its share among its largest users, including Metropolitan and Imperial. “It’s more dotting I’s and T’s,” he said, adding that he expected the language to go to agency boards “over the next few weeks.” The agreement must also clear the Arizona Legislature.
Since then, the legal picture has grown more complicated. Nevada sued the Interior Department on Aug. 24 in federal court in Nevada, arguing that the plan and its environmental review violated federal environmental and administrative law and misapplied the law of the river, according to a Congressional Research Service report updated Oct. 1. On Oct. 16, Arizona joined the suit, according to the University of Arizona’s Water Resources Research Center.
“Arizona has always been willing to do our part to protect the Colorado River, but we will not accept a forced federal plan that solves this crisis on the backs of our families, farmers, and businesses,” Gov. Katie Hobbs said, adding that the state would keep working with Nevada and California “to implement the Lower Basin Agreement.” California has not joined the lawsuit.
No public board vote approving the agreement had been recorded by Metropolitan or Imperial as of this week.
What the Senate committee has heard
The Senate Energy and Natural Resources Committee, chaired by Sen. Mike Lee, R-Utah, has jurisdiction over Reclamation and held its oversight hearing on the river in June, as the states’ talks stalled. At that hearing, Ms. Travnicek told senators the states had missed agreement deadlines on Nov. 11, 2025 and Feb. 14, 2026.
Sen. Martin Heinrich of New Mexico, the committee’s ranking Democrat, warned that without an agreement, “the consequences are clear: more litigation, unplanned water shortages, economic disruption, and heightened risk to communities least able to absorb it.” In a statement released with his remarks, he said: “What we cannot afford is delay. The basin needs compromise, shared sacrifice, investment, and leadership, and it needs them now.”
The Upper Basin states, Colorado, New Mexico, Utah and Wyoming, face no mandatory delivery cuts under the new guidelines. They had refused to accept fixed reductions, arguing that such cuts cannot be guaranteed in a basin where supply swings with the weather. According to the governor’s office, Arizona joined the lawsuit in part to hold the federal government accountable for not enforcing the Upper Basin’s delivery obligations to Lake Mead.
The administration has pointed to federal spending as part of its answer. Interior said more than $3 billion has been invested in the Lower Basin since January 2025 and that it is reviewing state proposals for water storage, desalination and other projects that could draw on funds from the 2025 tax and spending law.
The reservoirs
The conditions behind the cuts are severe. Interior said the combined contents of Lake Powell and Lake Mead were at their lowest since Lake Powell began filling in 1963, after the lowest snowpack on record in the winter of 2025-26. Reclamation said Lake Powell would release 6 million to 7 million acre-feet in the 2027 water year, as it tries to hold the reservoir at or above 3,510 feet to protect Glen Canyon Dam.
The guidelines include triggers in both directions. If Lake Mead is projected to fall below 1,010 feet within 12 months, the secretary must consult the basin states and tribes on further actions. If it is projected at 1,125 feet or higher in 2027 or 2028, the secretary will consult the Lower Basin states about increasing their deliveries.
For Californians, the river supplies roughly half of Metropolitan’s imported water and nearly all of the water that irrigates the Imperial Valley. The deliveries under the new rules begin Jan. 1.
Mr. Lee’s committee office, Mr. Heinrich’s office, the Bureau of Reclamation, the Colorado River Board of California and Metropolitan did not respond to requests for comment before publication.
Rosalind Achterberg covers the Senate Environment and Public Works and Energy and Natural Resources committees, from permitting and water law to nominations and the federal lands that cover nearly half of California, for the Inquirer’s Energy & Environment desk. More from Rosalind Achterberg
