Nevada takes legal action against federal Colorado River plan

Nevada filed a federal lawsuit on Monday challenging the Trump administration's new plan for reducing Colorado River deliveries, escalating a long-simmering dispute among the seven states that depend on the river. The suit was filed in federal district court in Nevada by the state of Nevada, the Colorado River Commission of Nevada and the Southern Nevada Water Authority against the Department of Interior and the US Bureau of Reclamation.

The legal action comes three days after Interior Secretary Doug Burgum signed the plan, which restricts water use in Arizona, California and Nevada — collectively known as the Lower Basin states. The plan, issued Friday, cuts roughly 20% from water supplied to the Lower Basin over the next two years, with the potential for further cutbacks later based on conditions.

Nevada Attorney General Michelle Briggs filed the lawsuit, which argues that the Interior Department's drought management plan would cause "devastating environmental, socioeconomic, and health and human safety impacts to southern Nevada and its citizens." The complaint contends the government misinterpreted, misapplied and violated the Law of the River, the compact that regulates water distribution from the Colorado River to seven Southwestern states.

The stakes for Nevada

Nevada officials say the cuts proposed under the federal framework could amount to up to a 71% reduction in the state's Colorado River water allocation. About 90% of the water used by Las Vegas and the surrounding area comes from the river.

Gov. Joe Lombardo framed the lawsuit as a matter of survival. "This isn't about political posturing," he said in a statement. "This is a matter of survival for a community that represents about two-thirds of our state's citizens and the lion's share of its economy."

Lombardo also criticized the plan for sparing Upper Basin states — Colorado, Utah, New Mexico and Wyoming — which he said were "not required to contribute a drop." He accused the federal government of trying to "roll Nevada and solve the entire Colorado River shortage on the backs of the Lower Basin states," adding, "Until that happens, we are prepared to fight for as long as it takes."

Nevada's arguments point to the state's conservation record. The state says it has reduced its demand on the Colorado River by 40% even as its population grew by 800,000 residents. John Entsminger, general manager of the Southern Nevada Water Authority, has previously said conservation has its limits, and the state argues the cuts are draconian and unfairly punish Las Vegas while not forcing Upper Basin states to share the burden.

Nevada's allocation is 300,000 acre-feet per year; under the worst-case scenario, it could be reduced to 86,500 acre-feet. The state also argues the environmental review behind the plan lacks adequate analysis of its impact on the region's $180 billion economy.

Broader context: Colorado River crisis and interstate conflict

The Colorado River supplies 40 million people, dozens of tribes and 5.5 million acres of farmland across the American West. The basin is experiencing historically low runoff and reservoir levels following decades of unprecedented drought spurred on by climate change, as well as long-term overuse.

The seven states that depend on the river have not reached an agreement on how to share the burden of enormous cuts needed to stabilize the system. The Upper Basin states have resisted mandatory cuts, insisting they source their supply from the headwaters and that Lower Basin states are responsible for declining water levels at Lake Mead and Lake Powell — the federally managed reservoirs that also supply hydroelectric energy to millions. The Lower Basin states, which have already agreed to take substantial cuts, are demanding their neighbors to the north share the burden.

Arizona, too, has voiced strong objections to the federal plan, outlining in a letter last week its belief that the plan violates the 1922 Colorado River Compact. Arizona water officials said they are evaluating Nevada's lawsuit. "We are evaluating Nevada's complaint and are working on a proper course of action moving forward," said Shauna Evans of the Arizona Department of Water Resources.

Framework details and future uncertainties

The federal plan takes 1.25 million acre-feet per year from the Lower Basin over the next two years. The three Lower Basin states had offered to absorb those cuts for two years; the dispute centers on the 10-year framework that could more than double cuts later in the decade.

For Arizona, next-year cuts are 760,000 acre-feet from the Central Arizona Project (CAP), and the framework could exceed CAP's entire capacity. Interior officials did not immediately comment on the lawsuit.

The current framework governing the river is set to expire in October 2026, and the 1922 Colorado River Compact is widely seen as outdated, doling out more rights than water. The river's users include a majority of water consumed in the Lower Basin, primarily for agriculture, while in Nevada the bulk goes to urban use.

Experts note the litigation could be the first of many court battles over the river's future. "This is a sticky situation," said Dr. John Berggren, regional policy manager at Western Resource Advocates, while Rhett Larson, a professor of water law at Arizona State University, said the case raises questions about the limits of federal authority over the river.

Perspectives

Nevada

Nevada argues the federal plan unfairly punishes the state and the Las Vegas region, which has already achieved significant conservation gains. The state says it has reduced Colorado River consumption by 40% while growing its population, and that the cuts would be devastating to its economy and residents. Nevada asserts that the federal government lacks authority to impose such cuts without forcing Upper Basin states to contribute, and that the plan violates the Law of the River.

Arizona

Arizona has said it evaluates federal water plans and will defend its water allocations in court if necessary. State officials voiced strong objections to the plan, arguing it violates the 1922 Colorado River Compact, and are now assessing Nevada's lawsuit as they consider their own options.

Upper Basin states

While not directly party to the lawsuit, the Upper Basin states (Colorado, Utah, New Mexico and Wyoming) have resisted mandatory cuts, maintaining that they source their supply from headwaters and that Lower Basin states are responsible for the declining levels of Lake Mead and Lake Powell.

Federal government

The Interior Department, which signed the plan, has not commented on the lawsuit. The plan is designed to reduce water deliveries to the Lower Basin over 10 years, with initial cuts of 1.25 million acre-feet per year for two years, and further reductions based on hydrological conditions.