As severe drought grips many western states in the U.S., Lake Powell's water level has dropped to its historic low since the lake filled after damming the Colorado River at Glen Canyon in 1963. /CFP

The nation's second-largest artificial reservoir, Lake Powell, is currently at 25 percent of capacity and has lost at least 7 percent of its total capacity. /CFP

The new level at Glen Canyon Dam is 11 meters above what's considered the "minimum power pool," the level at which its turbines would stop producing hydroelectric power. /CFP

The water loss has sparked public concern about whether the water supply will be adequate for hydropower generation, which millions of people in the western states rely on for electricity. /CFP