Water users across the American Southwest are now confronting the stark possibility of significant reductions in Colorado River usage, potentially impacting cities and agricultural operations by hundreds of billions of gallons, following the release of a new decade-long management plan by federal authorities. The Bureau of Reclamation published its proposed 10-year operational strategy, designed to adapt to fluctuating hydrological conditions that influence the river’s flow, with provisions for operational adjustments every two years. This plan outlines potential cuts to water allotments for the river’s Lower Basin states – Arizona, California, and Nevada – a move stemming from proposals originating within those very states. Meanwhile, the Upper Basin states, comprising Colorado, New Mexico, Utah, and Wyoming, are presented with the option of voluntary conservation measures.

This federal action arrives as existing interim guidelines and drought contingency plans, forged in 2007 and 2019, are slated to expire in 2027, and negotiations for a successor agreement have faltered, with the basin states repeatedly missing deadlines to reach a consensus. The Bureau of Reclamation, however, holds significant sway as it operates much of the river’s critical infrastructure, including the iconic Hoover and Glen Canyon Dams, which impound Lake Mead and Lake Powell, the two largest reservoirs in the United States. The final environmental impact statement released by Reclamation on Friday precedes a federal record of decision that will finalize the river’s operations for the upcoming two-year period.

Andrea Travnicek, the Interior Department’s assistant secretary for water and science, described the plan in a statement accompanying its release as striking "a balance between flexibility and predictability for the Colorado River system that is vital to the 40 million people who rely on it given unprecedented hydrologic conditions and the potential for considerable impacts on water users." She added that the plan "also allows a new flexibility to respond to changing conditions and potential consensus."

The agency is considering releasing between 5 million and 12 million acre-feet of water from Lake Powell, the reservoir that marks the boundary between the upper and lower basins, to downstream states. For context, one acre-foot of water can typically supply two to four households for an entire year. Under this framework, the Lower Basin, which also includes allocations for Mexico, could face substantial reductions in their water rights. Specifically, the plan suggests potential cuts of 1.5 million acre-feet in both 2027 and 2028.

Following a proposal submitted by the Lower Basin states, Arizona would see its annual allotment reduced by 760,000 acre-feet, California by 440,000 acre-feet, and Nevada by 50,000 acre-feet. The implications extend beyond these initial years, with the possibility of Lower Basin cuts reaching up to 3 million acre-feet annually after 2028. The Arizona Department of Water Resources deemed this figure "unacceptable," stating in an online statement that "Such reductions would devastate Arizona’s water users and its economy."

Reclamation appears to be seeking voluntary reductions from the Upper Basin, totaling up to 200,000 acre-feet, and has discussed the possibility of transferring water from federally managed dams within the basin downstream, contingent on hydrological conditions. JB Hamby, California’s Colorado River Commissioner, emphasized the necessity of these measures, stating, "The proposal responds to a fundamental reality: the Colorado River no longer reliably produces enough water to support all the uses and expectations built around it." He further commented, "That challenge is shared across the Basin, and addressing it requires specific, measurable reductions in water use by every state."

A spokesperson for the Colorado Department of Natural Resources indicated that the state is currently "analyzing" the document. Governors from the Upper Basin states expressed optimism in a joint statement, noting they were "encouraged that new operating guidelines will better reflect existing water supply, which must underpin any practicable plan going forward."

The Colorado River stands as one of the most climate-stressed waterways in the United States, supplying water to an estimated 35 to 40 million people across seven Western states, alongside 30 Native American tribes and two Mexican states. Its course winds through the arid Southwest, a region grappling with some of the nation’s most severe drought conditions. Millions of Western residents also depend on the hydroelectric power generated by the Hoover and Glen Canyon Dams.

The foundational 1922 Colorado River Compact, which allocated water rights among the river’s users, was predicated on an assumption of approximately 17.5 million acre-feet of available water for the two basins and Mexico. However, the historical average natural flow of the river has only been around 14.7 million acre-feet. Recent data from Reclamation reveals a precipitous decline, with the average flow plummeting to approximately 11.2 million acre-feet between 2020 and 2024. During this same period, the agency calculated average water usage and evaporative losses across the entire basin to be just over 13 million acre-feet, highlighting a critical deficit.

John Berggren, regional policy manager at Western Resource Advocates, viewed the proposed operational ranges as a necessary step toward addressing the imbalance. "The operational ranges that Reclamation put forward, they’re the right things that we need to be doing in order to fix the supply and demand imbalance," he stated. However, he cautioned, "But it is just a range, and what they actually do over the next two years or within any given year, that will matter if they’re actually gonna be able to bring the system back into balance." Berggren expressed hope that the short-term certainty provided by this plan could reinvigorate stalled negotiations among the states, urging, "I hope [the basin commissioners] don’t just keep doing what they’ve been doing for the last two or three years, ’cause that clearly hasn’t worked. I hope they try and take this opportunity to change things up. Let’s try something new and hopefully get to a seven-state agreement."

Reclamation’s environmental impact statement was originally intended to formalize a management plan that the basin states have yet to agree upon. Despite the missed negotiation deadlines, the Bureau of Reclamation has maintained an open door for a potential agreement, which is widely recognized as the most effective pathway toward a sustainable, long-term operating framework for the river.

The core of the impasse lies in the debate over whether water use reductions should be mandatory across the entire basin. The Lower Basin, having historically overdrawn its allocations, now uses less water than its apportioned share according to federal accounting, and advocates for future cuts to be shared equitably among all seven states. Conversely, the Upper Basin states, which have never fully utilized their legal water entitlements, have strongly resisted demands for mandatory cuts, proposing voluntary conservation efforts instead. These states argue that variable environmental conditions, such as the record-low snowpack experienced in recent years, inherently limit their water consumption.

Even with the federal government outlining potential management strategies, the absence of a comprehensive seven-state agreement significantly increases the likelihood of legal disputes, potentially leading to states suing one another and cases being adjudicated by the Supreme Court. Celene Hawkins, Colorado River program director at The Nature Conservancy, emphasized the importance of adaptive management, stating that proposing to manage the river in a way that responds to hydrological conditions is "the kind of agreement that we are going to need to really think about long-term how do we live in this basin with much less water moving forward." Hawkins expressed her hope that this federal action would serve as a catalyst for a seven-state agreement, enabling "really good work for communities and for the river itself."