While drought persists in more than 95% of the American West, water levels at the Hoover Dam have dropped to an all-time low, threatening the source of hydropower for an estimated 1.3 million people in California, Nevada and Arizona.
The water level in Lake Mead, the Colorado River reservoir that serves the Hoover Dam, dropped to 1,068 feet in July, the lowest since the lake first filled since the dam was built in the 1930s. The federal government is expected to announce for the first time a water shortage in the Colorado River this month, which will reduce the volume of water supplied from the river to neighboring states.
Widespread drought conditions in the Southwest over the past 20 years have caused Lake Mead to drop more than 130 feet in water levels since 2000.
According to the latest forecasts by the Bureau of Reclamation, made in July, the water level in the lake will drop another 31 feet by June 2023, to 1,037 feet.
To generate electricity, dams rely on tremendous pressure from the body of water they seal off. As the water level decreases, the pressure decreases and the dams, in turn, produce less hydroelectric energy, which means that the dam can produce less electricity.