Arizona, Nevada and Mexico will lose significant portions of their water supply in 2022 after a U.S. federal agency declared the first-ever water shortage condition at Lake Mead, a massive reservoir formed by the Hoover Dam on the Colorado River.
The U.S. Bureau of Reclamation announced on Monday that the projected water elevation in Lake Mead for Jan. 1 next year is 1,065 feet, which is 9 feet lower than the level which triggers the shortage condition.
As a result, Arizona’s annual water apportionment was reduced by 18 percent or 512,000 acre-feet. An acre-foot is the volume necessary to cover one acre of land with water. Nevada will lose 21,000 feet, and Mexico will lose 80,000 acre-feet, totaling 7 percent and 5 percent of their annual apportionment respectively.
“Like much of the West, and across our connected basins, the Colorado River is facing unprecedented and accelerating challenges,” Tanya Trujillo, the assistant secretary for water and science at the Department of the Interior, said in a statement.
Most of the water in the Colorado River comes from the Rocky mountains. The river’s basin in that area had a severely dry spring this year despite a regular snow season.
As a result, the unregulated inflow into Lake Powell, the amount which would have flowed to Lake Mead if not for the Hoover Dam, was approximately 32 percent of average, according to the Bureau of Reclamation. The total Colorado River water storage system was at 40 percent capacity as of Aug. 16, compared to 49 percent at the same time last year, according to the bureau.
The reductions in apportionment for Arizona and Nevada are the result of guidelines that have been in place since 2007, according to Trujillo. Mexico’s reduction is the result of an agreement reached in 2017.
“The basin is experiencing its 22nd year of drought and earlier this year the reservoirs reached their lowest level since they were originally built,” Trujillo said during a news conference.
Lake Mead and Lake Powell lost 50 percent of their capacity in the last five years alone, according to Bureau of Reclamation Deputy Commissioner Camille Touton.
“The announcement today is a recognition that the hydrology that was planned four years ago but we hoped we would never see is here,” Touton said.