Sunday, July 19, 2009

Not all dams are created equal

Dams are essential to human existence and well being, especially in semi-arid places like the American West. It is hard to imagine supporting 38 million people in California, as well as our world class agricultural economy, without holding winter rains and spring snowmelt in our reservoirs to provide water during our dry summers and perhaps subsequent drought years. In addition to water supply, dams also provide important flood control and hydropower benefits.

The cost of building dams to our natural environment, however, has been high. In some cases, we have decided to remove dams that provide limited utilitarian benefits in order to let rivers flow freely. In California, we have removed dams on Clear and Butte Creeks to help restore endangered winter and spring-run Chinook salmon and we hope to remove a few more on Battle Creek and the Ventura River. And last fall, Klamath River parties signed an “Agreement in Principle” that may well lead to the removal of four controversial dams and hopefully to restoration of the fisheries that have sustained Indian tribes in northern California for millennia.

The campaign to restore Hetch Hetchy Valley in Yosemite National Park is a bit different in that a restored valley would attract human visitors much like Yosemite Valley, its sister 20 miles to the south, does. If Hetch Hetchy Valley were returned to the American people, it is entirely possible that the correct balance between public access and excessive human footprint in Yosemite National Park could be found.

The reservoir currently in Hetch Hetchy Valley, unlike those behind the dams mentioned above, does provide some water supply benefits. The amount is surprisingly small, however, and there are alternatives for full replacement – see studies by the U.S. Bureau of Reclamation, the Environmental Defense Fund, U.C. Davis, as well as our own Restore Hetch Hetchy report. Some hydropower would need replacement as well – roughly the same amount as required for the Klamath proposal.

Reasonable people may disagree whether it is in our collective interest to restore Hetch Hetchy Valley. We at Restore Hetch Hetchy believe it is, and our realism about human needs is reflected in our mission statement:

The mission of Restore Hetch Hetchy is to return the Hetch Hetchy Valley in Yosemite National Park to its natural splendor while continuing to meet the water and power supply needs of all communities that depend on the Tuolumne River.

Please visit Restore Hetch Hetchy to learn more.

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