Water users across the American Southwest are facing the stark reality of substantial reductions in Colorado River usage, potentially numbering in the hundreds of billions of gallons annually, following the release of a new decade-long management plan by the federal government. The Bureau of Reclamation’s proposed framework, designed to adapt to shifting hydrological conditions affecting the river’s flow, includes provisions for operational adjustments every two years. This plan notably proposes significant cuts to water allotments for Arizona, California, and Nevada, comprising the river’s Lower Basin, while the Upper Basin states of Colorado, New Mexico, Utah, and Wyoming may implement voluntary conservation measures.

The existing interim guidelines and drought contingency plans, established in 2007 and 2019 respectively, are slated to expire in 2027, and recent negotiations among the basin states to forge a new agreement have faltered, with repeated deadlines for consensus passing unmet. However, the Bureau of Reclamation, which manages critical infrastructure such as the Hoover and Glen Canyon Dams that impound Lake Mead and Lake Powell—the nation’s two largest reservoirs—holds significant sway in determining the river’s future operations. The agency’s final environmental impact statement, released on Friday, precedes a federal record of decision that will finalize the river’s operational plan for the next two years.

"This plan strikes 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," stated Andrea Travnicek, the Interior Department’s Assistant Secretary for Water and Science, in an official release. She emphasized that the plan "also allows a new flexibility to respond to changing conditions and potential consensus."

Under consideration are releases from Lake Powell, a reservoir straddling the Utah-Arizona border that marks the division between the Upper and Lower Basins, ranging from 5 million to 12 million acre-feet for downstream states. An acre-foot, a unit of volume, can supply approximately two to four households for a year. The Lower Basin, which also includes Mexico, could see substantial reductions in their water allocations, potentially losing 1.5 million acre-feet in both 2027 and 2028, according to the proposal submitted by the Lower Basin states.

Within this proposed scenario, Arizona would experience a reduction of 760,000 acre-feet from its Colorado River allotment, California would lose 440,000 acre-feet, and Nevada would face a cut of 50,000 acre-feet. However, projections indicate that beyond 2028, Lower Basin cuts could escalate to as much as 3 million acre-feet. The Arizona Department of Water Resources has vehemently opposed this figure, labeling it "unacceptable" and warning that such reductions "would devastate Arizona’s water users and its economy."

The Bureau of Reclamation appears to be seeking voluntary reductions from the Upper Basin states, potentially 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, articulated the underlying challenge: "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. That challenge is shared across the Basin, and addressing it requires specific, measurable reductions in water use by every state."

Officials from the Colorado Department of Natural Resources indicated they are "analyzing" the document, while governors from the Upper Basin states expressed optimism, stating 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, 30 Native American tribes, and two Mexican states. Its path through the Southwest traverses some of the nation’s most arid and drought-afflicted landscapes, and millions of Western residents depend on the hydroelectric power generated by the Hoover and Glen Canyon Dams.

The foundational 1922 compact governing the river’s users assumed an annual availability of approximately 17.5 million acre-feet for the two basins and Mexico. However, the historical average natural flow has only been around 14.7 million acre-feet. This figure has plummeted significantly in recent years, averaging just 11.2 million acre-feet between 2020 and 2024, according to provisional data from the Bureau of Reclamation. During the same period, average use and evaporative losses across the basin were calculated by the agency to exceed 13 million acre-feet.

John Berggren, regional policy manager at Western Resource Advocates, commented that the operational ranges proposed by Reclamation are "the right things that we need to be doing in order to fix the supply and demand imbalance." However, he cautioned that these are merely ranges, and the actual decisions made over the next two years and within any given year will be critical to restoring the system’s balance. Berggren expressed hope that the short-term certainty provided by this plan will catalyze stalled negotiations among the states, urging basin commissioners to "try and take this opportunity to change things up. Let’s try something new and hopefully get to a seven-state agreement."

The Bureau of Reclamation’s final environmental impact statement was initially intended to formalize the management plan that the basin states have yet to agree upon. Despite the missed deadlines for state-level negotiations, Reclamation remains open to a collaborative agreement, which is widely considered the most effective route to a sustainable, long-term operating framework for the river.

Negotiations have been hampered by disagreements over whether water use reductions should be mandatory across the entire basin. The Lower Basin, which has historically overdrawn from the river, now utilizes less water than its allocated amount according to federal accounting, and advocates for shared future cuts across all seven states. Conversely, the Upper Basin states, which have historically used less than their full entitlement, have strongly resisted mandatory cuts, proposing voluntary conservation instead. These states argue that variable environmental conditions, such as record-low snowpack in recent years, already naturally limit their water consumption.

The absence of a unified seven-state agreement, even with the federal government proposing management options, heightens the likelihood of legal disputes between states dependent on the Colorado River, with potential adjudication by the Supreme Court. Nevertheless, the proposal to manage the river in an adaptive manner, responsive to hydrological shifts, is seen by experts as essential for long-term sustainability. "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," stated Celene Hawkins, Colorado River program director at The Nature Conservancy. Hawkins hopes this federal action will spur a seven-state agreement, enabling "really good work for communities and for the river itself."