Utah and other Upper Basin states "are not required to contribute a drop" of their Colorado River water to a federal plan for the region's reservoirs, Nevada's governor objects, while the southern half of his state faces a potential cut of more than 70 percent.

But the speaker of Utah's House wasn't sympathetic Monday, as Nevada filed a lawsuit against the Trump administration over what it alleges are "numerous legal and technical shortcomings" in the new 10-year framework for managing lakes Powell and Mead.

"Nevada is making an already difficult situation more difficult," Utah House Speaker Mike Schultz said in a statement. "Reaching an agreement requires every state to come to the table, respect the process and recognize its responsibility to be part of the solution. Litigation doesn't move us closer to an agreement."

Utah, he said, "will continue to protect its water rights and work toward a fair, workable solution for the entire Colorado River Basin."

Utah lawmakers set aside roughly $6 million that could be used for Colorado River lawsuits during the 2026 legislative session.

Nevada's lawsuit comes after states and the federal government have been in tense negotiations over how to manage the Colorado River after current guidelines expire at the end of this year.

Nevada Gov. Joe Lombardo (R) said in a statement that as his state has worked to conserve water, Upper Basin states throughout negotiations "have steadfastly refused to agree to any tangible reductions" in water use.

"We've already shown that we're willing to do our part, but the Colorado River is a shared resource, so the solution needs to involve everybody," Lombardo said. "Until that happens, we are prepared to fight for as long as it takes."

The federal government's plans, posted last week, include water cuts in Lower Basin states — Arizona, California and Nevada — but don't impose cuts in Upper Basin states: Utah, Colorado, New Mexico and Wyoming.

The secretary of the Interior is considered the "water master" in the Lower Basin and controls deliveries out of Lake Mead, but it does not have the same "responsibilities and authorities" in the Upper Basin, Andrea Travnicek, the department's assistant secretary of water and science, said in a media briefing on Friday.

Gene Shawcroft, Utah's Colorado River negotiator, and Amy Haas, director of the Colorado River Authority of Utah, declined The Salt Lake Tribune's requests for comment on the lawsuit on Monday.

Utahns face potential cuts each year based on the actual flow of water in streams and rivers, Shawcroft has previously noted, a point other Upper Basin states also have made. Farmers across Utah have taken cuts during this record drought year, Shawcroft told The Tribune on Friday.

Will other states sue?

Nevada's lawsuit claims that the federal government has failed to "adequately contemplate actions" that it can take in the Upper Basin, said Sarah Porter, director of Arizona State University's Kyl Center for Water Policy.

"Another big part of the complaint is Nevada's dissatisfaction with the [Bureau of Reclamation's] analysis of the socioeconomic impacts on Nevada," Porter added.

The lawsuit could turn into "a big, hairy court case," Porter told The Tribune. She said she'd be surprised if the other Lower Basin states, Arizona and California, don't also file similar lawsuits or join Nevada's lawsuit as plaintiffs.

"All of the allegations that Nevada makes are applicable in the other states, and most especially in Arizona," Porter said.

In the meantime, the lawsuit brings another level of uncertainty to Colorado River management.

"We're still evaluating, and we'll provide more information at a later date on how we're going to deal with this complaint," Tom Buschatzke, director of the Arizona Department of Water Resources, said in a public meeting on Monday.

"But it certainly adds a significant additional level of uncertainty," he said, "to all of the outcomes facing us."

'Matter of survival'

Lombardo said Nevada's lawsuit isn't about political posturing." Instead, he said, "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."

Nevada could have its 300,000-acre foot allocation of Colorado River water cut to less than 86,500 acre-feet. Las Vegas and surrounding cities used just under 212,500 acre-feet of water in 2024, according to Nevada's statement.

"Over the past 25 years, southern Nevada has become a global leader in water efficiency, reducing our Colorado River consumption by about 40 percent even as the community added 800,000-plus residents," John Entsminger, general manager of the Southern Nevada Water Authority, said in the statement.

"So we have clearly demonstrated our ability to adapt and do more with less," he said. "However, conservation has its limits, and there is just no way to meet even the basic needs of this community with the volume of water Interior has proposed."

The state of Nevada, the Colorado River Commission of Nevada and the Southern Nevada Water Authority are all plaintiffs in the lawsuit filed in federal district court.

Defendants include Interior Secretary Doug Burgum, the Department of Interior, the Bureau of Reclamation and Acting Commissioner Aubrey Bettencourt.

This article is published through the Colorado River Collaborative, a solutions journalism initiative supported by the Janet Quinney Lawson Institute for Land, Water, and Air at Utah State University. See all of our stories about how Utahns are impacted by the Colorado River at greatsaltlakenews.org/coloradoriver.