To some, the O'Shaughnessy Dam is a monument to the skills of the Irish-American engineer who built it. Elegant is the word that Susan Leal, general manager of the San Francisco Public Utilities Commission, uses to describe the curved wedge of rock and concrete that soars 300 ft. above the floor of the Hetch Hetchy Valley. But to others, the dam, constructed nearly a century ago inside the western boundary of Yosemite National Park, is a mocking tombstone to a landscape whose haunting beauty has lain for too long beneath 100 billion gallons of water.
Might the O'Shaughnessy Dam one day be dismantled and that drowned landscape conjured back into being? That is the provocative question posed by an activist group called Restore Hetch Hetchy, which five years ago launched a spirited but seemingly quixotic campaign to convince the public that the time has come to get rid of the unnatural bone lodged in the valley's throat. "This was done by people, and it can be undone by people," says Restore Hetch Hetchy's executive director Ron Good.
Undoing dams that have outlived their usefulness--or whose social and economic utility is overshadowed by the environmental harm they do--is an idea that is catching on. Over the past six years, some 175 dams have been dismantled across the country, and more than 600 over the past century. That's just a drop in the millpond, however, given that there are perhaps 2.5 million dams in the U.S. and that most of those removed to date have been relatively small and insignificant.
The O'Shaughnessy falls into a different category, and not just because it's so big. It's also quite useful: the cool, clear water it impounds flows to some 2.4 million people and 75,000 businesses in the San Francisco Bay Area, and the power generated by that water's downhill rush supplies electricity to such vital operations as San Francisco's schools, municipal-transit system and international airport. If the dam were removed, that water and power would have to be replaced somehow, which is why the Public Utility Commission's Leal considers the idea "just plain goofy."
And yet, buoyed by a series of Pulitzer-prizewinning editorials in the Sacramento Bee, two new books and technical studies commissioned by the Oakland, Calif., office of Environmental Defense, the Restore Hetch Hetchy campaign is stirring up more interest than anyone expected. This week the California Resources Agency is host to a daylong workshop on the Hetch Hetchy question that promises to look broadly at what is known about the costs--and the benefits--of pulling the dam down.
The O'Shaughnessy Dam was stirring controversy even before 1913, when the U.S. Congress, against the impassioned pleas of conservationist John Muir and his Sierra Club, voted through a bill allowing its construction. But though the debate is not new, the context has changed dramatically. On one hand, free-running rivers, unobstructed by dams, have become a rarity, which has increased their aesthetic, ecological and recreational value. On the other hand, with recent experience of protracted drought and soaring energy costs, Western states in particular are more worried than ever about the security of both their water supplies and sources of hydropower.