Interior proposes 21% cut to lower basin water amid allocation dispute
Interior proposes 21% lower basin cut; Arizona objects after failed three-year allocation talks.
Event / Environment
Colorado River Water Management
Ongoing dispute over water allocation reductions for lower basin states under new Interior Department management plan, including legal challenges and negotiations.
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2026-08-23 to 2026-11-08 · UTC publication dates
Coverage begins 23 Aug, 01:51 UTC
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What happened
Nevada claims proposed plan violates administrative law, environmental law, and Law of the River
Nevada's lawsuit alleges that the Interior Department's proposed Colorado River water allocation plan violates administrative law, environmental law, and the Law of the River—a collection of treaties, agreements, and court rulings that govern management of the Colorado River.
Lake Mead and Lake Powell reach record low water levels in August 2026
Lake Mead and Lake Powell, the nation's two largest reservoirs, have fallen to record low levels in August 2026 due to years of overuse and persistent drought conditions since 2000.
Arizona previously objected to Interior Department's Colorado River water plan
Arizona issued a letter on August 10 voicing objections to the Interior Department's proposed Colorado River water allocation plan and accusing the Interior Department of violating the 1922 Colorado River Compact.
Nevada would lose up to 213,556 acre-feet of Colorado River water allocation
Under the Interior Department's proposed plan, Nevada would face cuts to its 300,000-acre-foot annual Colorado River allocation by up to 213,556 acre-feet. This would reduce Nevada's allocation to less than 86,500 acre-feet per year. Southern Nevada, which includes Las Vegas and surrounding cities, used less than 212,500 acre-feet of water in 2024, with the Colorado River supplying approximately 90% of all water used in the Las Vegas Valley.
Interior Department proposes 21% reduction in Colorado River water allocation to lower basin states
The Department of the Interior released a new 10-year Colorado River management plan on August 21 that calls for a 21% reduction in water from the river to California, Nevada, and Arizona beginning in 2027. The four upper basin states—Colorado, Utah, New Mexico, and Wyoming—face no mandatory reductions under this framework and are only required to implement voluntary water reductions. The plan covers a two-year period starting in 2027.
Nevada files federal lawsuit against Interior Department over Colorado River water allocation plan
Nevada filed a federal lawsuit on August 24 against the Department of the Interior challenging a water distribution plan released August 21 for the Colorado River. The lawsuit names the Department of the Interior, Interior Secretary Doug Burgum, the U.S. Bureau of Reclamation, and its commissioner as defendants. Nevada, the Colorado River Commission of Nevada, and the Southern Nevada Water Authority filed the suit in federal court in Las Vegas.
Lawsuit alleges Interior Department failed to analyze economic impacts and consider alternatives
Nevada's lawsuit alleges that Interior Department officials did not adequately analyze the impact of water cuts on Southern Nevada's economy, failed to consider alternatives to the proposed reductions, and did not fully respond to public comments regarding mitigation measures. The complaint states that decision-makers and stakeholders are left unclear about how the federal government interprets and applies the Law of the River.
Southern Nevada has reduced Colorado River water consumption by 40% over 25 years
Southern Nevada reduced its Colorado River consumption by approximately 40% over the past 25 years while the region added more than 800,000 residents. The Southern Nevada Water Authority general manager stated that conservation efforts have demonstrated the community's ability to adapt and do more with less water.
States fail to reach agreement after three years of negotiations on Colorado River water sharing
Seven Colorado River basin states—California, Arizona, Nevada, Colorado, Utah, New Mexico, and Wyoming—spent more than three years attempting to renegotiate the current Colorado River water allocation plan, which was set to expire in 2026. The states were unable to reach an agreement, with upper basin states refusing to accept mandatory water reductions despite the decades-long Western drought.
Colorado River supplies water to one in 10 Americans and generates power for 6 million people
The Colorado River supplies water to approximately one in 10 Americans and generates electrical power for 6 million people across seven states in the Southwest.
U.S. Department of Interior orders 1.25 million acre-feet annual Colorado River water cuts for 2027-2028
The U.S. Department of the Interior announced on Friday that it would reduce the delivery of 1.25 million acre-feet of water annually for the next two years beginning in 2027 to Lower Basin states. The agency also warned that additional cuts over the next 10 years are possible depending on hydrology.
Nevada to reduce Colorado River water allocation by 50,000 acre-feet
Nevada will lose 50,000 acre-feet of its Colorado River water allocation annually for 2027-2028 under the voluntary agreement negotiated by Lower Basin states.
Colorado River Basin experiencing 26-year prolonged drought
The Colorado River Basin is in a 26-year prolonged drought period intensified by climate change and rising temperatures. Last winter saw the worst recorded snowpack in the basin's history, adding severe stress on the water system.
Arizona to reduce Colorado River water allocation by 760,000 acre-feet
Under a voluntary agreement negotiated by the three affected Lower Basin states in May, Arizona will absorb the largest share of federal water cuts, losing 760,000 acre-feet of its Colorado River water allocation annually for 2027-2028.
Lake Mead reaches lowest water level since filling began nine decades ago
Lake Mead, one of the nation's two largest reservoirs fed by the Colorado River, has plummeted to its lowest water level since it began filling approximately 90 years ago.
Glen Canyon Dam risks losing hydroelectric power generation capacity
If water levels in Lake Powell fall just 33 more feet, the reservoir will no longer meet the water levels needed to generate hydroelectric power through Glen Canyon Dam, preventing water from moving through the dam into the Colorado River.
Current Colorado River water-sharing rules expire in October
The rules currently governing how the Colorado River's water is divided among seven states are scheduled to expire in October. The seven states have been unable to reach a consensus on a long-term framework for sharing the shrinking supply.
Interior Department requests voluntary conservation of 700,000 acre-feet of water over two years
The Department of the Interior's operating guidelines encourage California, Nevada and Arizona to voluntarily conserve and store at least 700,000 acre-feet of water over the two-year period beginning in 2027 to protect the Colorado River system, in addition to the mandated 1.25 million acre-feet per year of reductions.
Colorado River provides water to 35-40 million people across seven states and Mexico
The Colorado River serves as a water supply source to an estimated 35 to 40 million people according to the Bureau of Reclamation, including 40 million people across the United States, millions of acres of farmland and ranchland, and industries powering the American West.
California to reduce Colorado River water allocation by 440,000 acre-feet
California will face a reduction of 440,000 acre-feet of its Colorado River water allocation annually for 2027-2028 under the voluntary agreement negotiated by Lower Basin states.
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2 alternative perspectives
Nevada sues Interior Department over Colorado River water cuts
Nevada challenges Interior Department's Colorado River allocation plan as legally insufficient and economically harmful.
Glen Canyon Dam faces hydroelectric capacity loss amid historic drought
Glen Canyon Dam faces potential hydroelectric capacity loss due to historic drought and federal Colorado River water cuts.
Interior seeks voluntary conservation as water-sharing rules near expiration
Interior requests voluntary 700,000 acre-feet conservation as Colorado River water-sharing rules expire.
Colorado River Basin enters 26-year drought, reservoirs hit record lows
Colorado River Basin's 26-year drought pushes major reservoirs to record lows.
Federal order mandates 1.25 million acre-feet Colorado River cuts through 2028
Federal order mandates 1.25 million acre-feet Colorado River cuts, with Arizona absorbing the largest reduction.