+/- Worth a Dam?

Article excerpt

John Muir called it "one of Nature's rarest and most precious temples." California's Hetch Hetchy Valley was at one time as sublime as nearby Yosemite Valley. But in 1913 the US Congress passed a taw approving a massive dam in Yosemite National Park, and Hetch Hetchy Valley became a reservoir designed to feed water and electricity to the booming city of San Francisco. Now, a century later, an effort is underway to tear down the dam and bring the valley back to life. Proponents say draining the reservoir would make for one of the most ambitious environmental restoration efforts ever. Opponents say that demolition would sacrifice an important source of renewable energy. The debate is bigger than this one reservoir, iconic though it is. The fight over the future of Hetch Hetchy is part of a global discussion over what to do with existing darns around the world, and how to balance the desire for landscape restoration with the need for clean energy generation.


by Spreck Rosekrans

Spreck Rosekrans is director of policy for Restore Hetch Hetchy. He has more than two decades of experience working with cities, farmers, tribes, and fishermen to find practical solutions for managing water and power in California and other Western states.

One hundred years ago, Yosemite's Hetch Hetchy Valley was one of the most spectacular places in the United States. Carved by glaciers and surrounded by towering cliffs punctuated with waterfalls thundering onto a serene valley floor, Hetch Hetchy was described as a twin to the now world-famous Yosemite Valley that lies 20 miles to its south.

When San Francisco proposed to build a dam and flood Hetch Hetchy Valley, more than 100 newspapers across the country responded with outrage. President Theodore Roosevelt initially rebuffed the city's efforts to dam the Tuolumne River at the mouth of the valley But in 1906, after an earthquake and fire devastated San Francisco, Congress and President Woodrow Wilson relented and allowed the city to construct the O'Shaughnessy Dam. The valley was drowned under 300 feet of water.

Congress's decision to allow the dam sparked reform of the National Park system. No such industrial development has been allowed in a national park since. And Hetch Hetchy's damming has inspired generations of conservationists to protect our natural heritage and to commit to safeguarding our protected areas.

There are thousands of dams in the United States. Many are vital pieces of infrastructure that provide reliable water supplies, hydropower, flood control, and recreation. The O'Shaughnessy Dam, however, has caused significant environmental damage and its modest benefits can be replaced. We now have the opportunity to bring Hetch Hetchy back to life.

It's important to understand that the Hetch Hetchy Reservoir is only marginally important for ensuring delivery of water and electricity to the San Francisco Bay Area. For proof, see the reports by the United States Bureau of Reclamation (1988), Environmental Defense Fund (2004), and UC Davis (2006) that have studied the issue--all available at www.hetchhetchy.org.

First look at the water situation. San Francisco's water system includes eight other reservoirs that collectively hold several times the volume of Hetch Hetchy. When (not it) O'Shaughnessy Dam is decommissioned, those reservoirs will still be in operation and the main major pipelines from the Sierra Nevada foothills to the Bay Area will still be in use.

In dry years, about 20 percent of the current water supply will need replacement. Given that San Francisco does not recycle a single drop of water and has virtually abandoned the use of groundwater, modernizing the city's water system could easily make up the difference. Twenty percent is much less than what other communities in the state have done in recent years to help with restoration programs for fish, birds, and other forms of wildlife. …