The Colorado River is delivering less water to Phoenix and Las Vegas this year, and the reductions could get substantially worse. In its annual operating plan, the U.S. Bureau of Reclamation declared a Level 1 shortage for Lake Mead for the 2026 water year, triggering mandatory cuts of 512,000 acre-feet to Arizona, 21,000 acre-feet to Nevada, and 80,000 acre-feet to Mexico under separate binational agreements. Those reductions are already being built into utility planning across the region.
But the bigger fight is over what comes next. The legal framework that governs how shortage pain is divided among Western states, the 2007 Interim Guidelines and the 2019 Drought Contingency Plan, expired at the end of 2025. Federal officials are now evaluating five alternatives for post-2026 river operations through a Draft Environmental Impact Statement, and some of those options would impose cuts far deeper than anything the Lower Basin has absorbed so far.
What the 2026 shortage means right now
Under the current shortage declaration, Arizona takes the largest hit. Nearly all of the state’s 512,000 acre-foot reduction falls on the Central Arizona Project canal, the 336-mile aqueduct that carries Colorado River water uphill to the Phoenix metropolitan area and Tucson. CAP water is a critical supply source for roughly five million people in central Arizona, and the cuts reduce deliveries that cities, farms, and tribes had counted on for the year.
Nevada’s 21,000 acre-foot reduction is smaller in absolute terms, but it lands on a state with a far thinner margin. Nevada’s entire Colorado River allocation is just 300,000 acre-feet per year, the smallest of any Lower Basin state. The Southern Nevada Water Authority, which supplies Las Vegas and surrounding communities, draws about 90 percent of its water from Lake Mead…