Arizona is preparing for a potential legal battle over its Colorado River water rights as negotiations with other states stall, Governor Katie Hobbs’s office announced Monday, March 23, 2026.
Legal Preparations Underway
The state has retained the law firm Sullivan & Cromwell, which has experience arguing water cases before the U.S. Supreme Court. This move allows Arizona to prepare for a legal fight, though no lawsuit has been initiated. A decision on whether to pursue legal action will reach after the U.S. Department of Interior adopts new guidelines this summer for sharing the dwindling river’s resources among Arizona, California, and Nevada.
Without a seven-state agreement, the new federal guidelines are expected to disproportionately impact Arizona’s water supply. Arizona has argued that the Upper Basin states – Colorado, New Mexico, Utah, and Wyoming – must not fail to allow 7.5 million acre-feet of water to pass Lees Ferry in northern Arizona annually, as stipulated in the 1922 Colorado River Compact.
Central Arizona Project at Risk
Arizona’s vulnerability stems from its lower priority status for Colorado River water, established when the state sought congressional approval for the Central Arizona Project (CAP). CAP officials have argued that if the Lower Basin bears the brunt of new restrictions, the canal—which has augmented local supplies for decades—could be effectively cut off.
Negotiations have been complicated by disagreements over the utilize of reservoirs like Flaming Gorge to restock Lake Powell. The Rocky Mountain states contend their users already face challenges due to climate change, while Arizona maintains these reservoirs were intended to help the Upper Basin meet its compact obligations.
Frequently Asked Questions
What is Arizona doing to address the Colorado River crisis?
Arizona has hired the law firm Sullivan & Cromwell to prepare for a potential legal battle over its Colorado River water rights and has designated $3 million for litigation, with another $1 million proposed in a current bill.
Why is Arizona particularly vulnerable to cuts?
Arizona accepted a lower priority for Colorado River water when seeking approval for the Central Arizona Project, meaning it is more likely to face cuts if the Lower Basin bears the brunt of new restrictions.
What is the Colorado River Compact of 1922?
The Colorado River Compact of 1922 states that the Upper Basin states must not fail to allow 7.5 million acre-feet of water to pass Lees Ferry in northern Arizona each year on average.
As the Colorado River continues to shrink, what steps will be necessary to ensure equitable water distribution among the states and protect vital resources for the future?
