Monday, March 21, 2011

Is Lake Powell slowly dying?

Tom Wharton in the Salt Lake Tribune: Some say Lake Powell and Lake Mead are slowly dying. Others maintain the Colorado River reservoirs, two of North America’s largest, are doing just fine. These experts say they not only meet current needs but have the potential for pipelines that bring water into Denver and St. George as well as a nuclear power plant on the Green River.

How the water is managed over coming years has enormous consequences for the West. At stake are the growth potential for many major Western cities that rely on Colorado River water for drinking, crops grown in California, cheap hydroelectric power, recreation enjoyed by millions each year, the ecological health of the Grand Canyon and the survival of several endangered fish.

“Everyone predicts that Lake Powell’s days are numbered,” said Dan McCool, professor of political science and environmental studies at the University of Utah, adding that all models looking at climate change indicate that it is going to get drier and warmer in the Colorado River Basin, reducing future flows.

In 2007, Western states and the federal government signed an agreement specifying what happens when water is in short supply. When the level of Lake Mead drops below a certain elevation, more water is released from Lake Powell in a process called equalization.

In its latest study, the Bureau of Reclamation (BOR), which manages the system, put the probability of a 2011 equalization release from Lake Powell to Lake Mead at 97 percent. The release will likely be 11.63-million acre-feet instead of the usual 8.23 million, about 40 percent more than usual. The final decision won’t be made until April. If the release occurs as expected, there likely won’t be a water shortage in the lower basin states of Nevada, Arizona and California in 2012…

The Glen Canyon Dam and, behind it, Lake Powell with a bathtub ring of some 80 feet, shot by Brian Thomas, under the Creative Commons Attribution-Share Alike 3.0 Unported license

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