The U.S. Bureau of Reclamation has proposed a 10-year water-sharing framework for the Colorado River that could slash supplies by as much as 3 million acre-feet annually for Arizona, California and Nevada. The cuts, which equate to reductions of up to 40 percent from current allocations, would be adjusted every two years based on reservoir conditions and are intended to prevent further depletion of Lake Mead and Lake Powell amid persistent drought and overuse.
The plan, outlined to the seven basin states late last week, responds to the expiration this fall of the 2007 interim guidelines that have governed operations since 2007. Those rules expire without a replacement agreement after states failed to reach consensus on a longer-term deal. Under the federal proposal, annual releases from the two reservoirs would range between 5 million and 12 million acre-feet, likely trending toward the lower end without significant new precipitation in the Rockies.
Federal Proposal Calls for Up to 40% Colorado River Cuts to Protect Reservoirs, Threatening Arizona Supplies
Arizona water officials described the scenario as deeply concerning. Tom Buschatzke, director of the Arizona Department of Water Resources, called the proposal “sobering” at a May 15 stakeholder meeting, warning it could eliminate deliveries through the Central Arizona Project canal that serves Phoenix, Tucson and agricultural users across the state. The CAP holds junior priority under the 1922 Colorado River Compact, placing it among the first to lose water in severe shortages.
The Lower Basin states—Arizona, California and Nevada—offered in early May to cut at least 1.6 million acre-feet per year through 2028, with additional voluntary conservation measures. Federal modeling shows the new proposal nearly doubles that reduction in a worst-case year. Patrick Adams, senior water policy adviser to Gov. Katie Hobbs, said the 3 million acre-foot figure “is alarming” and “would be devastating” if fully implemented, though he noted it remains a modeled scenario rather than a guaranteed outcome.
Brenda Burman, general manager of the Central Arizona Project and a former Reclamation commissioner, urged federal acceptance of the states’ offer as a bridge to stability. “We’ve offered an opportunity for two years of stability to the entire basin,” she said. “They should take it.”
The framework would allow five successive two-year operating plans, giving flexibility to respond to hydrology and potential breakthroughs among the states. Upper Basin states have resisted mandatory cuts on their users, while Lower Basin states have shouldered larger initial reductions. Arizona has prepared legal options, including a potential Supreme Court challenge, if the federal government imposes deeper cuts without corresponding upstream contributions.
The proposal marks a shift toward shorter-term, adaptive management after years of deadlock. Without swift agreement, officials warn, the risk of reservoirs falling below critical thresholds for hydropower and downstream deliveries will continue to grow.