Side-by-side NASA satellite photos show Lake Mead at its driest since 1937

• Water levels at Lake Mead reached their lowest point since the lake was filled in the 1930s.
• The drought-stricken reservoir helps supply water to 25 million people in the Southwest. 
• Climate change-fueled droughts have contributed to the lake's receding water levels.

New satellite images released by NASA illustrate how Lake Mead's water levels have dramatically declined over the last 22 years.

"The largest reservoir in the United States supplies water to millions of people across seven states, tribal lands, and northern Mexico," the space agency said in a news release. "It now also provides a stark illustration of climate change and a long-term drought that may be the worst in the US West in 12 centuries."

Photos shared by the NASA Earth Observatory capture Lake Mead's thinning waterways in 2000, 2021, and 2022. 

Even in the one-year span between 2021 and 2022, Lake Mead's waters shrank. Since January 2022, the lake lost more than 25 feet of water, according to water data from the Bureau of Reclamation. The agency predicts levels to drop another 20 feet by next summer.

Water levels are now at their lowest since the lake was filled in 1937, according to NASA.

As of July 25, water elevation at Lake Mead was at 1,040 feet. At full capacity, Lake Mead would be 1,220 feet deep near the dam and would hold 9.3 trillion gallons of water. The last time the lake approached full capacity was in 1999, NASA said. 

Lake Mead, which straddles Nevada and Arizona, is a key reservoir that helps supply water to 25 million in the Southwest. Last year, government officials declared a water shortage in Lake Mead for the first time since its construction in the 1930s.

The shrinking water levels have been linked to an decades-long drought that's gripped the Southwestern US. 

A growing body of research attributes intensifying droughts to climate change. Rising global temperatures cause changes in precipitation and enhance evaporation. At Lake Mead, local precipitation and groundwater account for about 10% of the lake's water, according to NASA. 

In recent months, Lake Mead's shrinking shores revealed long-submerged items, including human remains, sunken boats, and more.