Map Reveals Fastest Declining Lakes in US

Newsweek analysis shows Lake Mead, Lake Powell, Great Salt Lake, Salton Sea, and Walker Lake losing water at alarming rates.

Published on Mar. 9, 2026

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A new Newsweek analysis has mapped out the five American lakes with the fastest-declining water levels: Lake Mead, Lake Powell, the Great Salt Lake, Salton Sea, and Walker Lake. These major reservoirs and lakes across the western U.S. are seeing dramatic drops in water levels due to prolonged drought, increased demand, and upstream diversions, raising concerns about water supplies, hydroelectric power, and recreation.

Why it matters

Water levels in major lakes and reservoirs across the western United States have a significant impact on drinking water supplies, hydroelectric power generation, and agricultural irrigation for millions of people. Sustained declines in lake elevations can also expose shoreline infrastructure, affect recreation industries, and reduce available water storage during periods of drought or increased demand.

The details

Lake Mead, which straddles the Nevada-Arizona border, is the largest reservoir in the U.S. but is now less than 10 feet from reaching critical water-shortage levels. Lake Powell, the second-largest man-made reservoir in North America, is currently only 25% full. Utah's Great Salt Lake has lost 73% of its water and 60% of its surface area since the mid-1980s. California's Salton Sea is projected to continue shrinking as inflows remain lower than evaporation. And Nevada's Walker Lake has lost 90% of its volume due to upstream water diversions for agriculture over the past century.

  • Lake Mead's water level is now less than 10 feet from reaching critical shortage levels.
  • The Great Salt Lake has lost roughly 4 inches of elevation each year since the mid-1980s.
  • Salton Sea projections indicate the shoreline could continue retreating in the coming decades.

The players

Lake Mead

The largest reservoir in the United States, spanning roughly 250 square miles and holding about 9.3 trillion gallons of water when full. It straddles the Nevada-Arizona border and is a key storage point for water from the Colorado River.

Lake Powell

The second-largest man-made reservoir in North America, covering about 161,000 acres and able to hold roughly 27 million acre-feet of water at full capacity. It stretches across the Utah-Arizona border and is a key part of the Colorado River storage system.

Great Salt Lake

The largest natural lake west of the Mississippi River and the largest saltwater lake in the Western Hemisphere, located in Utah. It has lost roughly 73% of its water and 60% of its surface area since the mid-1980s.

Salton Sea

California's largest lake by surface area, covering about 376 square miles and able to hold roughly 7.5 million acre-feet of water. Projections indicate the shoreline could continue retreating in the coming decades as inflows remain lower than the roughly 1.3 million acre-feet of water lost to evaporation each year.

Walker Lake

A terminal lake in western Nevada, covering about 30,000 acres and fed primarily by the Walker River and seasonal snowmelt. Water diversions for agriculture over the past century have contributed to a 90% decline in the lake's volume.

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The takeaway

The dramatic declines in water levels across these major lakes and reservoirs in the western U.S. highlight the urgent need to address water scarcity and management challenges posed by prolonged drought, increased demand, and upstream diversions. Protecting these vital water resources will be crucial for supporting communities, industries, and ecosystems in the region.