Lake Mead Could Be Dry by 2021

Sea Technology, Mar 2008

There is a 50 percent chance Lake Mead, a key source of water for millions of people in the southwestern United States, will be dry by 2021 if climate changes as expected and future water usage is not curtailed, a new study finds.

Without Lake Mead and neighboring Lake Powell, the Colorado River system has no buffer to sustain the population of the Southwest through an unusually dry year, or worse, a sustained drought, the study says. In such an event, water deliveries would become highly unstable and variable.

The research team concluded that human demand and natural forces such as evaporation are creating a net deficit of nearly one million acre-feet of water per year from the Colorado River system, enough water for roughly eight million people.

"We were stunned at the magnitude of the problem and how fast it was coming at us," said marine research physicist and study coauthor Tim Barnett of the Scripps Institution of Oceanography of the University of California, San Diego. "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."

The Lake Mead/Lake Powell system includes the stretch of the Colorado River in northern Arizona. Aqueducts carry water from the system to Las Vegas, Nevada; Los Angeles and San Diego, California; and other communities in the Southwest.

The scientists estimate that there is a 10 percent chance that Lake Mead could be dry by 2014. They further predict that there is a 50 percent chance that reservoir levels will drop too low to allow hydroelectric power generation by 2017.

Barnett also said that the researchers chose to go with conservative estimates of the situation in their analysis, and the water shortage is likely to be more dire in reality.