Aug. 16 (UPI) -- Nevada's Lake Mead, the largest reservoir in the West, could fall below a critical threshold in just two years if a new forecast by the Bureau of Reclamation is correct.
A report Wednesday said there is a 52 percent chance that water levels at the lake will fall below 1,075 feet elevation by 2020. If that happens, it could trigger the first-ever federal shortage declaration on the Colorado River, a reservoir that supplies water to 40 million people.
As of Wednesday, water levels stood at 1,078 feet.
Colorado River users are hoping regional efforts to conserve water pay off and leave enough of their unused supplies in the lake to stave off a shortage declaration.
"Every single human being is a water user," Jennifer Pitt, Colorado River program director for the National Audubon Society, told the Arizona Republic. "The prospect of a continued drought without that policy in place really puts all of us at risk."
The report came as Arizona managers and stakeholders try and finalize a drought-contingency plan
Arizona, which would be one of the first states hit with cutbacks, could lose about half its Colorado River water if a shortage is declared.
Lake Mead, formed during the Great Depression by the blocking of the Colorado River with Hoover Dam, has endured droughts before. In 2016, the lake dropped 10 feet in three months, and held an average depth of 1,084 feet.