Arizona joins Nevada lawsuit challenging federal Colorado River water plan

Arizona filed a motion on Friday to intervene in Nevada's lawsuit that challenges the federal government’s new operating framework for the Colorado River. The state’s Department of Water Resources director, Tom Buschatzke, said the plan unfairly penalizes the three Lower Basin states—California, Nevada and Arizona—by ignoring key legal principles and risking severe water reductions.

The Interior Department’s proposal, released after the states failed to reach a consensus, would reduce water deliveries to the three states by about 20 percent over the next two years. Buschatzke warned that the steepest cuts allowed under the plan could "effectively dry up" the Central Arizona Project, a major water system serving much of the state.

The Interior Department did not respond to a request for comment.

"Like Nevada, Arizona believes the federal government’s new operating framework ignores basic elements of the law of the river and could result in cuts … that would devastate Arizona’s economy," Buschatzke said.

The lawsuit seeks to halt the implementation of the plan while the states negotiate a more equitable allocation of water resources.