PHOENIX -- The Bureau of Reclamation said Arizona could be pulling less water out of the Colorado River starting in 2016 if the Rocky Mountain snowpack doesn't improve.
That snowpack feeds the Colorado River, which supplies water to 40 million users in seven western states, including Arizona. Rose Davis with the Bureau of Reclamation said the Central Arizona Project could see the first shortage in its history in three years.
"The CAP has been conserving water so they may have plans to deal with the upcoming projections."
And if the dry years continue in the Rockies, Davis said there's a "48 percent chance of lower basin water supply shortages."
Under the current water agreements, Arizona receives about 10 times the amount of water that Nevada does from the Colorado River, while California's share is more than both states combined. In the event of a shortage, both states would see reductions while California would not lose any of its allotment.
The trigger mechanism for declaring a water shortage is when Lake Mead water levels reach 1,075 feet. It came close in 2010 at 1,082 feet. Mead is at 1,114 feet.
The Central Arizona Project is designed to bring about 1.5 million acre-feet of Colorado River water per year to Pima, Pinal and Maricopa counties. It is a 336-mile long system of aqueducts, tunnels, pumping plants and pipelines and is the largest single resource of renewable water supplies in the state of Arizona.