Key Points:

• The Arizona Department of Water Resources has retained the law firm Sullivan & Cromwell

• The announcement comes as negotiations over Colorado River sharing remain stalled

• Despite pleas from Gov. Katie Hobbs, the federal government has not intervened

Arizona is retaining legal counsel in preparation for a potential court battle over the Colorado River, according to Gov. Katie Hobbs’ office.

The Arizona Department of Water Resources has hired the law firm Sullivan & Cromwell to represent the state’s position as negotiations remain at a standstill and federal intervention on behalf of the Lower Basin seems unlikely. 

The Upper Basin states of Colorado, Utah, Wyoming and New Mexico and the Lower Basin states of Arizona, California and Nevada have entered a third year of negotiating guidelines for sharing the river after 2026. The announcement comes after negotiators missed two federally-imposed deadlines to reach a deal, one in November and the other in February. 

No consequences appeared to come from missing the deadlines, but in January the Bureau of Reclamation issued a draft environmental impact statement with five alternatives to the river’s current operating guidelines. Arizona’s leaders oppose all five alternatives and have asked the bureau to revoke the draft EIS.

Hobbs has repeatedly called on leaders at the Department of the Interior to step in and serve as mediators in the stalled negotiations, but to no avail. She made one such plea on March 17 during a U.S. Chamber of Commerce summit in Washington, D.C., imploring President Donald Trump and his administration to recognize the threat to Arizona’s Colorado River allocation as a national security issue. 

“Let me be very clear, this administration’s goals rely on Arizona receiving our fair share of Colorado River water,” Hobbs said. “It relies on Arizona-made missiles, Arizona-made semiconductors, and Arizona grown-agriculture … This administration must step in, show leadership and help the seven states come to a reasonable and fair agreement to ensure Arizona has the ability to defend our nation, feed our nation and build the high tech economy of our nation’s future.”

Hobbs’ office says it is currently unclear on what shape the litigation will take as the seven states await action from the federal government. A decision from the Department of the Interior on the draft EIS is likely to come around June, which will help the state better understand its legal position. 

Depending on the department’s decision, Arizona may sue the federal government or the Upper Basin states. Officials in Hobbs’ office say they believe Arizona has a very strong case based on delivery obligations outlined in the 1922 Colorado River Compact, which requires the Upper Basin to deliver 7.5 million acre feet of water to the Lower Basin annually.  

Colorado Attorney General Phil Weiser told lawmakers in his state in January that his office has built up a team ready for litigation, while California and Nevada have obtained counsel for a Supreme Court showdown, according to Hobbs’ office. Arizona allocated $3 million to a Colorado River Litigation Fund in 2025, and state lawmakers are hoping to add even more money to the fund during this year’s budget process. 

Hobbs has long said that a negotiated agreement is still the preferred outcome, but that possibility is seeming less and less likely. Arizona’s chief water negotiator, ADWR Director Tom Buschatzke, is still engaged in weekly negotiation meetings though, according to Hobbs’ office. 

The seven Colorado River states are currently operating under a temporary deal brokered in 2023, intended as a bridge to negotiate a 20-year agreement set to take effect in 2027. As part of those negotiations, Arizona has agreed to reduce its Colorado River usage by 1.5 million acre feet, which amounts to 27% of the state’s allocation. 

Hobbs has said the state is willing to cut more, but only if the Upper Basin states agree to reductions in their supply. The Upper Basin states have argued they should not be forced to make cuts because they historically have not used their entire Colorado River allocation, while California and Arizona have regularly used more than their allotted share. 

The stakes have only been raised by a dismal winter on the Colorado River watershed, which brought a snow drought and record-high temperatures. The Department of Interior hopes to finalize new operating guidelines for the river by Oct. 1.