Nevada preached peace on the Colorado River. Now it’s suing to protect its water.

Nevada, long seen as a cooperative voice in Colorado River water talks, has sued the federal government over its new plan for managing the river. The move surprised water experts, since Arizona was expected to sue first over deeper cuts to its own supply. Nevada argues the federal plan could allow a 71 percent cut to the Las Vegas area's water supply in a worst-case scenario, and that this violates the law and skipped consideration of other options, like changes to how Glen Canyon Dam operates.

The dispute stems from failed talks among the seven Colorado River states to agree on how to share water cuts before the river's current rules expire in October. With no deal reached, the Interior Department stepped in with its own plan, leaning on cuts to Arizona, Nevada, and California to keep the river's major reservoirs from dropping too low. Because Nevada sends nearly all its river water to cities rather than farms, it has less flexibility to absorb cuts than states that can idle farmland instead.

For homeowners in the Las Vegas area, this means the size of future water cuts is now tied up in court rather than settled. Nevada hasn't asked for an emergency order to block the plan yet, but if it wins, the ruling could disrupt the short-term water-sharing arrangement meant to guide operations through 2028. Experts say this lawsuit is unlikely to end negotiations between the states, but it adds uncertainty to how much water the region can count on in the coming years.