The Associated Press

Fri, Feb 15, 2008 (5:25 a.m.)

Changes in climate and strong demand for Colorado River water could drain Lake Mead by 2021, triggering severe shortages across the region, scientists warn.

Researchers at San Diego's Scripps Institution of Oceanography said Tuesday the West's largest storage reservoir faces increasing threats from human-induced climate change, growing populations and natural forces like drought and evaporation.

There is a 50 percent chance Lake Mead will run dry by 2021 and a 10 percent chance it will run out of usable water by 2014, if the region's drought deepens and water use climbs, the researchers said.

"We were stunned at the magnitude of the problem and how fast it was coming at us," said marine physicist Tim Barnett. "Make no mistake, this water problem is not a scientific abstraction but rather one that will impact each and every one of us that live in the Southwest."

Currently, Lake Mead _ located in Nevada and Arizona _ is half-full, as is Lake Powell. Both lakes help manage water resources for more than 25 million people in seven states.

Researchers said that if Lake Mead water levels drop below 1,000 feet, Nevada would lose access to all its river allocation, Arizona would lose much of the water that flows through the Central Arizona Project Canal, and power production would cease before the lake level reached bottom.