Low Lake Mead prompts first-ever federal declaration of shortage; farmers' Colorado River water will be reduced

People take pictures of Lake Mead near Hoover Dam on Aug. 13. The lighter layer of minerals shows the high-water mark of the reservoir. (Associated Press photo by John Locher)

"Low water in the Colorado River’s largest reservoir triggered the first-ever federal declaration of a shortage on Monday, a bleak marker of the effects of climate change in the drought-stricken American West and the imperiled future of a critical water source for 40 million people in seven states," report Karin Brulliard and Joshua Partlow of The Washington Post. "Water in Lake Mead, the mammoth reservoir created by the Hoover Dam that supplies the lower Colorado basin, is projected to be 1,065.85 feet above sea level on Jan. 1, nearly 10 feet below a threshold that requires Arizona, Nevada and Mexico to reduce their consumption in 2022. On Monday, it was just under 1,068 feet, or about 35 percent full, according to the U.S. Bureau of Reclamation, which manages the water that states and Mexico have rights to use." The lake hasn't been that low since it began filling after completion of the Hoover Dam in the 1930s." 

The water-supply cuts triggered by the declaration will mostly affect Arizona farmers—at first. "Beginning next year they will be cut off from much of the water they have relied on for decades. Much smaller reductions are mandated for Nevada and for Mexico across the southern border," Henry Fountain reports for The New York Times. "But larger cuts, affecting far more of the 40 million people in the West who rely on the river for at least part of their water supply, are likely in coming years as a warming climate continues to reduce how much water flows into the Colorado from rain and melting snow."

The mandatory cuts "are part of a contingency plan approved in 2019 after lengthy negotiations among the seven states that use Colorado River water: California, Nevada and Arizona in the lower basin, and New Mexico, Utah, Colorado and Wyoming in the upper basin. American Indian tribes and Mexican officials have also been involved in the planning," Fountain reports. "The shortage announced Monday affects only the lower basin states, but the Bureau of Reclamation may declare a similar shortage for the upper basin, perhaps as early as next year."