Las Vegas Water Source Could Run Dry By 2021 - Study

PlanetArk 13 Feb 08;

SAN FRANCISCO - Chances are about even that Lake Mead, the prime source of water for the desert city of Las Vegas, will run dry in 13 years if usage is not cut back, according to study released on Tuesday.

The finding is the latest warning about water woes threatening the future of the fast-growing US casino capital and comes amid a sustained drought in the American West.

The study by two researchers at the Scripps Institution of Oceanography at the University of California San Diego, calculates a 10 percent chance that Lake Mead will run dry in six years and a 50 percent probability it will be gone by 2021 absent other changes.

"Our reaction was frankly one of being stunned," study co-author Tim Barnett, a marine research physicist, said in an interview. "We had not expected the problem to be so severe and so up close to us in time."

Climate change -- both man-made and natural variation -- strong human demand and evaporation are all factors affecting water in the lake. "The biggest change right now is taking more water from the bucket than we are putting into it," Barnett said.

The uncertainty about when and if the lake will run dry stems from the natural fluctuations of the Colorado River, the researcher said.

The West has suffered years of drought with the Colorado supplying less water to Lake Mead, which serves Nevada, California, Arizona and Mexico.

The lake created by Hoover Dam provides 90 percent of Las Vegas' water and is less than half full, giving the edge of the lake a bath tub ring visible even far away by air.

(Reporting by Adam Tanner; editing by Todd Eastham)

Lake Mead Could Dry Up by 2021
Andrea Thompson, LiveScience Yahoo News 12 Feb 08;

Lake Mead, a key source of water for millions of people in the southwestern United States, could go dry by 2021, a new study finds.

The study concludes that natural forces such as evaporation, changes wrought by global warming and the increasing demand from the booming Southwest population are creating a deficit from this part of the Colorado River system.

Along with Lake Powell, which is on the border between Arizona and Utah, Lake Mead supplies roughly 8 million people in the cities of Las Vegas, Los Angeles, and San Diego, among others, with critical water supplies.

The system is currently only at half capacity thanks to a recent string of dry years, researchers say.

The study’s findings indicated that there is a 10 percent chance that Lake Mead could be dry by 2014 and a 50 percent chance that reservoir levels will drop too low to allow hydroelectric power generation by 2017. There is a 50 percent chance the lake will go dry by 2021, the study says.

Researchers say that even if water agencies follow their current drought contingency plans, those measures might not be enough to counter natural forces, especially if the region enters a period of sustained drought or if human-induced climate changes occur as currently predicted.

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

Several studies in recent years have predicted a prolonged period of drought in the Southwest as a result of global warming.

The team's analysis of Federal Bureau of Reclamation records of past water demand and calculations of scheduled water allocations and climate conditions indicate that the system could run dry even if mitigation measures now being proposed are implemented.

"It's likely to mean real changes to how we live and do business in this region," said coauthor David Pierce, a climate scientist at Scripps.

The new study has been accepted for publication in the journal Water Resources Research.