The two largest reservoirs in the United States have both dropped below any level ever recorded. Lake Mead, behind Hoover Dam, set its all-time low in early August, and Lake Powell, upstream on the Colorado River, followed on August 15 and then broke its own new record again on September 10.
The Colorado River system supplies more than 40 million people across the Southwest and about 5 million acres of farmland, and federal figures posted on September 27 show neither lake has recovered.
Two records, two months
NOAA’s National Integrated Drought Information System, in its summer 2026 drought review, lists Lake Mead as reaching an all-time official record low on August 7 and Lake Powell doing the same on August 15. The Mead figure most widely reported was 1,040.50 feet above sea level on August 6, which edged under the 1,040.58 feet recorded in July 2022, according to a Straight Arrow News report. The margin was about a tenth of a foot, a small gap that carried a large symbolic weight.
Powell’s decline was steeper. NASA’s Earth Observatory reported that the reservoir fell to 3,517.24 feet on September 10, passing the previous low of 3,519.92 feet set on April 13, 2023, in its account of the record. The report, republished on ScienceDaily on September 22, blames “an exceptionally dry and warm winter” that left the basin short of its usual snowmelt, and NASA’s own text describes a snow drought and unusually warm temperatures across the Colorado Basin in 2026 after a meager winter snowpack in the upper basin.
Where the lakes stand now
Bureau of Reclamation operating data for September 27 put Lake Mead at 1,037.79 feet, holding 6,826,000 acre-feet, and Lake Powell at 3,517.64 feet, holding 5,131,000 acre-feet, per the bureau’s Lower Colorado River levels page. Mead was therefore nearly three feet below its August record, and Powell had ticked up only about four-tenths of a foot from its September 10 low, so both reservoirs sit at or near the lowest points ever measured.
The gaps to the operating limits are small in one case and larger in the other. Mead’s 1,037.79 feet is 2.79 feet above the 1,035-foot mark tied to Hoover Dam’s output, while Powell’s 3,517.64 feet is about 27.6 feet above its 3,490-foot minimum power pool. Reclamation’s own numbers therefore leave Mead with very little cushion and Powell with more, though Powell’s supply is being propped up by releases from another reservoir.
Jack Schmidt, director of the Center for Colorado River Studies at Utah State University, cautioned that a record figure needs interpretation. “Every record that’s broken is a teaching moment,” he said, arguing that the conditions behind the figure matter more than the figure. He pointed to the lack of winter recovery from historically low snowpack and warm spring temperatures.
The thresholds ahead are concrete. If Mead falls to 1,035 feet, roughly 70 percent of Hoover Dam’s power generation would cease, and the Bureau of Reclamation projects the lake will approach that level by November, according to the same report. Powell’s minimum power pool is 3,490 feet, below which its hydroelectric turbines cannot operate.
Emergency releases and a wider drought
Reclamation began stabilization measures in April, releasing extra water from Flaming Gorge Reservoir into Powell and reducing Powell’s releases downstream into Mead. NASA noted that officials also canceled a planned controlled flood meant to rebuild fish habitat and skipped an August “cool mix” release intended to protect native species. Those steps moved water and protected Powell’s elevation, but they did so by drawing on other reservoirs and giving up environmental programs.
The reservoir records sit inside a broader dry season. NIDIS reported that 47.6 percent of the country was in drought on August 25, down from 48.8 percent on June 2 and a mid-summer low of 38.3 percent on July 21, and that ten of the twelve major Reclamation reservoirs were below average as of August 30. As of September 15, wildfires had burned more than 8.4 million acres across 55,419 fires, which NIDIS put at 147 percent of the 10-year average for acreage and 125 percent for the number of fires. Among the season’s notable fires, NIDIS lists the Spokane Complex Fire in eastern Washington, which damaged or destroyed more than 800 structures including hundreds of homes, and the Big Grass Fire in eastern Oregon, which burned 578,637 acres and is described as the largest wildfire in modern Oregon history.
Whether Mead reaches the 1,035-foot line Reclamation projects for November will be the next measurable test of how far the river’s lower basin has slipped.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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