New report feeds controversy over California’s Hetch Hetchy dam

Activists have pushed for over 20 years to restore Yosemite National Park’s Hetch Hetchy Valley to its natural state by knocking down a now 82-year-old dam and draining a 117-billion-gallon reservoir. This week, a California state report indicated that the project is technically feasible — although the price tag would run between $3 billion and $10 billion. Critics of the proposal, including the San Francisco Public Utilities Commission, say it would affect water quality and quantity for 2.4 million Bay Area residents and disrupt a hydroelectric system that provides San Francisco with a fifth of its energy. Project backers say it could be done without impacting water supply or power, and have in the past estimated that the cost would be closer to $1 billion. “If we don’t have to use one of America’s spectacular natural cathedrals as a reservoir, we shouldn’t,” says Tom Graff of Environmental Defense. Hearings will be held in the state legislature on the issue in August; draining the reservoir could ultimately require an act of Congress.