Lake Powell hits record low, threatening key water and electricity supply for millions

For Tucson residents, Lake Powell’s record low is a warning that Arizona’s Colorado River supplies remain under growing pressure. The reservoir reached its lowest recorded elevation Saturday, adding to concerns about water management, electricity production and the future of a river system that supports more than 40 million people across seven states. Arizona is among the states that depend on the Colorado River and could face major reductions under a proposed federal plan, making conditions at Lake Powell relevant well beyond northern Arizona.

Lake Powell fell to 3,519.91 feet above sea level, according to data from the U.S. Bureau of Reclamation. That level is slightly below the previous record, set in April 2023. The reservoir has dropped more than 20 feet since the beginning of the year, a rapid decline that reflects the broader deterioration of the Colorado River system. Lake Mead, the river’s other major reservoir, reached a historic low about a week earlier.

The two reservoirs are the largest storage facilities on the Colorado River, and their condition affects the region’s ability to manage water through dry periods. Both are now at their lowest levels in nearly 70 years, with federal data indicating that they could continue falling. A recent paper by academics and retired water officials found that the reservoirs’ combined storage had not been this low since May 1957, when Glen Canyon Dam, which holds back Lake Powell, was still under construction. Lake Powell began filling in 1963.

The decline is the result of several pressures working together. Water use has remained too high for the amount flowing into the river system, while a record dry winter and rising temperatures have further reduced supplies. The combination has steadily depleted Lake Powell and Lake Mead. The current crisis is therefore not the result of one isolated dry spell, but part of a problem that has developed over years across the Colorado River Basin.

Lake Powell’s shrinking volume also threatens hydroelectric generation. The reservoir is now roughly 30 feet from the elevation at which its turbines would stop producing electricity. Federal officials warned in April that avoiding that threshold by the end of the year would require a “major intervention.” Hydropower from Glen Canyon Dam is one of the benefits tied to Lake Powell, so continued declines could affect an important source of electricity for communities and infrastructure across the region.

The situation is unfolding as federal officials and the seven Colorado River states work toward a long term management agreement. The states are Arizona, California, Nevada, New Mexico, Utah, Wyoming and Colorado. They have not reached a final agreement on how to manage the river as available water decreases. In July, the Bureau of Reclamation proposed a 10 year plan that includes the possibility of substantial water cuts for Arizona, California and Nevada. The proposal places Arizona’s future Colorado River allocation directly in the wider negotiations.

That uncertainty is significant for Tucson and other Arizona communities, even though Lake Powell is located near Page in northern Arizona. The record at Powell does not by itself announce an immediate change to Tucson’s water service, but it underscores the conditions shaping decisions about Arizona’s Colorado River supply. The state is one of the communities and economies facing possible reductions under the federal proposal, while officials attempt to keep the river system functioning for residents, farms, businesses, wildlife and power users.

The effects are already visible at Lake Powell itself, including in the tourism industry surrounding the reservoir and Glen Canyon National Recreation Area. As water levels have receded, boat ramps have closed or been moved, additional ramps have been built and marinas have temporarily shifted into deeper water. A photograph from July showed the Wahweap Marina floating on the declining lake near Page. Those changes demonstrate how low water is affecting both the reservoir’s practical operations and the businesses that depend on visitors.

Lake Powell’s new record, coming so soon after Lake Mead’s historic low, gives negotiators less room for delay as they consider the next decade of Colorado River management. The reservoirs’ combined storage has reached a level not seen since the era when Glen Canyon Dam was being built, and the possibility of losing hydroelectric generation adds another layer of urgency. For Arizona, including Tucson, the central question is how future water cuts and management decisions will be distributed while the river continues to face overuse, warmer conditions and limited precipitation.