Low Water Levels in Lake Powell and Lake Mead in August 2026

The two largest reservoirs in the United States approached record low levels in the summer of 2026. Short- and long-term droughts, plus below-average winter snowfalls, diminished water supplies across the Colorado River watershed, which feeds into Lake Powell and Lake Mead. The river system supplies water to approximately 40 million people and 5 million acres of farmland in Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, and California.

The first image pair shows Lake Powell, the second largest reservoir in the U.S. According to the National Integrated Drought Information System, lake levels are "critically low at 22% full (33% average)." The U.S. Bureau of Reclamation (USBR) reported a reservoir level (pool elevation) of 3,518.79 feet above sea level as of August 23. The previous low, set in April 2023, was 3,519.92 feet. 

The comparison above shows the difference in the lake's extent on August 8, 2014 (left), and August 1, 2026 (right). Swipe the center bar left and right to see the differing water levels. The images were acquired by the Operational Land Imager (OLI) aboard the Landsat 8 and 9 platforms. The images are provided through the Harmonized Landsat Sentinel-2 (HLS) project and were chosen for their clear, cloud-free views at comparable times of the year.

Downstream, the largest reservoir in the U.S.—Lake Mead—reached its lowest level (1,039.77 feet according to USBR) since it was filled in 1937. The comparison above shows Lake Mead on August 14, 2016, and August 17, 2026. The true-color reflectance images were acquired by the MultiSpectral Instrument (MSI) aboard the European Space Agency's Sentinel-2A and B platforms. 

NASA Earth Observatory published closeups and the long-term story of changes along a section of Lake Powell.

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