Lake Mead, seen here on April 3, has plummeted in recent years amid an epic drought. A wet winter is now prompting federal officials to release more water downstream into the reservoir.
CNN  — 

After years of punishing drought, a historic winter snowpack is bringing a reprieve to the Colorado River Basin and the nation’s largest reservoirs.

The US Bureau of Reclamation announced Thursday that this winter’s rain and the projected runoff from above-normal snowfall is expected to boost its water releases this year from Lake Powell to Lake Mead by 2.5 million acre-feet. That’s an extra 814 billion gallons water, and welcome news for the communities, farmers and tribes who rely on the reservoir.

In total, Glen Canyon Dam, which forms Lake Powell, is now expected to release up to 9.5 million acre-feet of water downstream to Lake Mead and its Hoover Dam – the equivalent of nearly 4.7 million Olympic-sized swimming pools. It far exceeds the 7 million acre-feet release that was initially expected, but was boosted after the bureau analyzed annual snow runoff projections this month.

Water levels at Mead have plummeted over the last few years, dropping so low that they revealed ancient volcanic rock, previously sunken boats and several bodies. With that additional water, officials project that Lake Mead’s water elevation is expected to rise to about 1,068 feet by the end of the year – approximately 33 feet higher than they projected last month, and around 25 feet higher than it was at the end of 2022.

The snow and the amount of liquid water stored in it on the surrounding mountain peaks is well-above average for this time of year. Once it melts, that precipitation will serve as a lifeline for 40 million people in the Western US – including Los Angeles, Phoenix, and Las Vegas – who depend on it for drinking water, crop irrigation and hydropower.

Still, even with this winter’s incredible snowpack, federal officials are warning that one good year is not enough to reverse many years of severe drought. Lakes Powell and Mead still have a combined storage capacity of just 26%, officials said.

“This winter’s snowpack is promising and provides us the opportunity to help replenish Lakes Mead and Powell in the near-term — but the reality is that drought conditions in the Colorado River Basin have been more than two decades in the making,” Reclamation commissioner Camille Calimlim Touton said in a statement. “Despite this year’s welcomed snow, the Colorado River system remains at risk from the ongoing impacts of the climate crisis.”

Reclamation and the Interior Department are analyzing what dramatic, additional water cuts could look like to prevent the river basin from crashing. One scenario could severely wipe out Arizona’s allotment of Colorado River, since the state has a junior priority compared to California. The agencies are expected to finalize a decision on new water cuts later this summer.