Federal water managers are projecting Lake Mead will drop to levels in January 2017 that could force supply cuts to Arizona and Nevada.
Arizona's water allocation could be cut 11.4 percent and Nevada's by about 4.3 percent.
A closely watched U.S. Bureau of Reclamation report released Monday predicts water levels will be just 2 feet above a trigger point next January on the Colorado River reservoir supplying much of the Southwest's drinking water.
The so-called interim guidelines chart a decline leading to a declaration of a shortage the following year.
Operations chief Dan Bunk says it all depends on the weather.
Lake Mead on Monday was 37 percent full, with a surface level 1,077 feet above sea level. That's down 144 feet from full in 1983.
The trigger point is at 1,075 feet.
