Arizona Hires Sullivan & Cromwell for Colorado River Water Fight

Katie Hobbs, Governor of Arizona, announced the retention of New York-based law firm Sullivan & Cromwell to represent the state in potential litigation over Colorado River water rights. The move follows more than two years of failed negotiations between Lower Basin states—Arizona, California, and Nevada—and Upper Basin states—Colorado, New Mexico, Utah, and Wyoming—to update a water-sharing agreement that expires in October 2026.

Arizona officials seek to prevent an inequitable split of shrinking water supplies, alleging that Upper Basin states refuse to share the burden of cuts despite a 20% decrease in river flow over the last century. The state is particularly concerned that the United States Bureau of Reclamation's draft environmental impact statement could cut supplies to the Central Arizona Project canal system by 77%, potentially damaging the state's economy.

While Governor Hobbs intends to pursue a negotiated settlement, the state is preparing for legal action as early as June. Representation may involve administrative proceedings before the Department of the Interior or arguments before the U.S. Supreme Court if the federal government unilaterally imposes restrictions. To fund these efforts, state lawmakers established a $3 million fund for legal fees, with a possible additional $1 million allocation.