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

Water levels in Lake Powell have reached a new record low. The Colorado River reservoir is now about 22% full.

The nation’s second-largest reservoir covers parts of Utah and Northern Arizona. If it drops much lower, that could force the shutdown of hydropower turbines that send electricity to about 5 million people.

Lower than that, the dam could have trouble sending water downstream at all, jeopardizing the supply for major cities like Phoenix, Las Vegas and Los Angeles.

This news comes after another water milestone. Just downstream, Lake Mead, the nation’s largest reservoir, hit a historic low last week.

Science

Lake Mead, nation's largest reservoir, hits record low

Alex Hager

The reservoir, which straddles the Arizona-Nevada border, has suffered due to an imbalance between supply and demand for Colorado River water.

The records are the result of drought, climate change and steady demand for Colorado River water.

Policymakers are trying to agree on a new plan to rein in demand for the river over the next two years. It’s expected to be released in the coming weeks.

Lake Powell’s elevation drop

Plummeting water levels pose a major threat to the Colorado River Basin, which is a key resource for wildlife, hydropower and more than 40 million people in seven U.S. states.

The historic lows come as the federal government and states that rely on the river — California, Arizona, Nevada, New Mexico, Utah, Wyoming and Colorado — struggle to reach agreement on a long-term management plan for the dwindling resource. Persistent overuse combined with a record-dry winter and rising temperatures have been depleting both Lake Powell and Lake Mead.

Lake Powell’s elevation dropped to 3,519.91 feet above sea level on Saturday, dropping just slightly below a previous record set in April 2023, according to data from the U.S. Bureau of Reclamation. The lake is more than 20 feet lower than it was at the start of the year, USBR data shows.

The reservoir is now about 30 feet away from the point at which turbines would stop producing hydroelectric power. Federal officials warned in April that a “major intervention” would be necessary to avoid reaching that threshold by the end of this year.

USBR in July proposed a 10-year plan that includes major potential water cuts for Arizona, California and Nevada.

The crisis has been in the making for years. Both reservoirs are at the lowest they have been in nearly seven decades, and levels may continue to drop, USBR data shows.

The last time their combined storage was this small was in May 1957 when Glen Canyon Dam that holds back Powell was being built, according to a recent paper published by a group of academics and retired water officials. Powell began to fill in 1963.

The depletion has also impacted Lake Powell’s substantial tourism industry, forcing marinas in the reservoir to adapt. Boat ramps have closed or moved, new ones are being added and marinas have been temporarily relocated to deeper waters.