Central Arizona Project Joins Lawsuit Over Federal Water Cuts

"The actions by the federal government disregard the Colorado River Compact and other laws governing the Colorado River," Brenda Burman, the general manager of the Central Arizona Project, said in a news release Tuesday. "Those of us who share this precious resource have no choice but to turn to the courts to correct those errors."

Burman’s statement marks the formal entry of one of the West’s most powerful water agencies into a legal battle against the Trump administration. The Central Arizona Project (CAP), which delivers Colorado River water to the Phoenix metro area, announced its intent to join a lawsuit originally filed by the state of Nevada. The suit targets the federal government’s recently announced ten-year management plan for the basin’s key reservoirs, Lakes Mead and Powell.

To hear them tell it, the core issue is fairness — or the lack thereof. The federal plan mandates steep, mandatory water cuts for the three Lower Basin states: Arizona, California, and Nevada. However, the plan only asks upstream states, such as Colorado, to voluntarily reduce their usage. For downstream users like CAP, this asymmetry is the sticking point.

The stakes are tangible. Under the proposed 2027–2028 management plan, downstream states must cut their annual use by 1.25 million acre-feet. That represents a 20% reduction through 2028. More alarmingly, federal guardrails allow these forced cuts to escalate to 3 million acre-feet per year. According to Arizona officials, reductions of that magnitude could effectively dry up the CAP canal system — a critical infrastructure network for the region.

The timeline leading to this litigation has been contentious. For three years, the seven basin states have argued over how to manage the reservoirs following the expiration of the 2007 management rules on September 30. Federal officials initially deferred to the states, expecting a unified proposal. Instead, the states missed deadline after deadline. Without a consensus by August, the Trump administration stepped in, announcing its own plan effective October 1.

Now, the question is whether the courts will side with the downstream states and CAP. As of Thursday, a judge had not yet ruled on the two motions from Arizona to join the lawsuit, and no hearing date has been set. But with CAP now in the mix, the legal pressure on the administration is building.

"We have no choice but to turn to the courts," Burman said. It’s a sentiment that likely resonates with many along the river, where the math of the new cuts doesn’t quite hold up against the reality of the dry years ahead.