Water over the dam

ANYONE WHO PROPOSED damming and inundating Hetch Hetchy Valley today would be run out of the state before you could say “John Muir.” But a century ago, the great naturalist fought in vain to preserve the valley, which rivals Yosemite Valley for granite-walled grandeur. Instead, it was filled with water and became a reservoir for San Francisco.

The construction of O’Shaughnessy Dam was unquestionably a mistake. But it’s not at all clear that dismantling the dam and restoring the valley is the right thing to do now.

An admirably impartial state report brought some clarity to the issue this week. It is entirely feasible to drain Hetch Hetchy and still provide San Francisco with water. But restoring the valley would be hellishly expensive -- $3 billion to $10 billion. Environmentalists had said it would cost far less.

People can and do continue to quibble over the expense -- would it really take up to $1.8 billion, as the state says, for engineering, legal and paperwork alone? -- but the prohibitive bottom line remains. Restoring Hetch Hetchy is a beautiful environmental dream. But it does not belong on anyone’s short list of priority projects.

Not only must the cost of restoring Hetch Hetchy be balanced against the laundry list of state infrastructure needs, it also must be weighed alongside bigger environmental threats. Located within Yosemite National Park, Hetch Hetchy is protected from further damage in ways that many other wild resources are not. The billions of dollars needed to restore it could buy a lot of land threatened with development or oil drilling. The money could be used to protect the habitat of a species that might otherwise go extinct, or to combat air pollution in national parks and forests.

By contrast, the main idea behind restoring Hetch Hetchy is to open it to tourism and recreation -- a worthy goal, certainly. It is not, however, especially urgent. If we someday decide we want to pay whatever it costs to enjoy the Hetch Hetchy Valley instead of the Hetch Hetchy Reservoir -- well, the valley will still be there decades from now.

Until that day comes, there is one question that hasn’t been asked but should be: Why isn’t Hetch Hetchy open to limited recreation as it is, as a spectacularly scenic lake where people could fish or use non-motorized boats? The fact that water fills the valley to a depth of 300 feet doesn’t make the valley’s nearly 2,000-foot cliffs less imposing.

San Franciscans would undoubtedly squawk, as they do over any proposal that would affect their water supply. And the regional water district might have to upgrade the reservoir’s water-treatment system. But the state should be asking this question -- and ending the debate over whether it should be spending millions more to study a currently unaffordable water project.