Lake Powell, the second-largest reservoir in the United States and the water bank that supplies drinking water, electricity and irrigation to more than 40 million people across seven western states, dropped to a record low elevation of 3,519.91 feet on Saturday, edging below the previous all-time low of 3,519.92 feet set in April 2023.
The milestone came nine days after downstream Lake Mead, the country's largest reservoir, hit its own all-time low.
The reservoir is now more than 20 feet lower than it was at the start of 2026, driven by a record-dry winter, a 26-year drought and rising temperatures that are evaporating what little runoff arrives.
The reservoir is about 30 feet above the point at which the Glen Canyon Dam can no longer generate hydroelectric power, a threshold called minimum power pool, below which water cannot flow through the turbines. Losing that power would eliminate a significant source of electricity across the Southwest.
Seven states, California, Arizona, Nevada, New Mexico, Utah, Wyoming and Colorado, depend on the Colorado River and are currently unable to agree on a long-term management plan.
The reservoir's tourism industry has also been hit hard, with boat ramps closing and marinas relocating to deeper water.
The bathtub ring of white minerals on Lake Powell's canyon walls, visible for miles, marks how far it has fallen.