S.F. Use of Hetch Hetchy Studied

City doesn't need the Yosemite reservoir, grad student says.

by Mark Grossi
The Fresno Bee - December 28, 2003

A San Francisco could do without that 117 billion-gallon reservoir filling a spectacular glacial valley in Yosemite National Park.

So says Sarah Null, a University of California at Davis graduate student who has written a master's thesis on the removal of San Francisco's controversial Hetch Hetchy Reservoir in Yosemite.

Sidestepping a bitter, century-old debate, Null found that the Bay Area's far-flung water-delivery system could work without Hetch Hetchy Reservoir, a conclusion cheered by environmentalists and questioned by San Francisco officials.

"I think it can be done," said Null, who is working on a geography doctorate at Davis. "I ignored institutional and political implications so I could focus on water supply and economics. I find it helpful to think outside the box."

The box, in this case, carries a lot of legal, political and emotional baggage, but less scientific grist.

Null's thesis will no doubt be tossed in.

Her work comes at a time when the San Francisco Public Utilities Commission is crafting a $3.6 billion overhaul of the old Hetch Hetchy system, a 167-mile series of tunnels, aqueducts and pipelines that delivers water to 2.4 million people.

Since conservation icon John Muir lost the fight against O'Shaughnessy Dam in 1913, environmentalists have been waiting for this moment. It's an opportunity to re-evaluate the need for the reservoir.

The Sierra Club, Environmental Defense, Restore Hetch Hetchy and others consider O'Shaughnessy a monumental mistake. They have believed all along that San Francisco could live without Hetch Hetchy Reservoir.

If the dam were removed, Yosemite would again have the valley with eye-catching waterfalls and soaring granite cliffs. Muir called Hetch Hetchy a geologic twin of Yosemite Valley, which is about 25 miles to the south.

But Bay Area officials have long defended the 360,000-acre-foot reservoir as essential for San Francisco's water and power. The Tuolumne River water coming from Yosemite is so pure that the city is among only a handful of major American municipalities without expensive filtration.

Indeed, the emotional sparks between outraged environmentalists and supposedly "green" Bay Area politicos are as spectacular as they are ironic.

The UC Davis thesis, however, is not an emotional issue, say officials at the San Francisco Public Utilities Commission. It's simply not complete, they say. The thesis needed to include discussions of the Tuolumne River's complex water rights, which would have a big impact in the real world of restoration.

"Nobody has ever disputed that it is possible to eliminate O'Shaughnessy Dam from the water system," said city PUC general manager Patricia Martel. "Bring me the numbers, and we will talk about it. But this thesis has some incorrect assumptions and does not give a full discussion."

Martel said the city would entertain any viable proposal that maintained pristine water quality, hydroelectric power generation and reasonable cost.

Environmentalists believe Null's work would be a good launching pad for a more developed study to take to the city.

Environmental Defense, a national activist organization, is planning such a detailed look at removing the dam, which was completed in 1923 and enlarged in 1938.

Environmental Defense economist Spreck Rosekranz said Null's work offers more detail than he has seen before.

"It is a solid piece of work," he said. "An engineer and an economist put together the model she used."

The science is intricate, but the idea is simple: New Don Pedro Reservoir, downstream of Yosemite on the Tuolumne, is about six times larger than Hetch Hetchy. Remove O'Shaughnessy Dam, and let the river run down to Don Pedro. Then, create a canal or pipeline to funnel water from Don Pedro into the Hetch Hetchy Aqueduct, which runs to the Bay Area.

There would be enough water for the city, Null said. But San Francisco would lose about $12 million worth of hydropower income because of reduced use of power plants near Hetch Hetchy.

But that problem pales next to the cost of filtering water, which would be required under Null's scenario.

She estimated the cost of a filtration plant at $2 billion and the yearly costs of filtering the water at about $13 million.

"The costs would be offset by recreation income when Hetch Hetchy Valley is restored in Yosemite," Null said. "But the money wouldn't go to San Francisco."

That would be unacceptable to the city, which has rights to the water and the dam under federal law passed in 1913, Martel said. She added that any detailed feasibility study on removing O'Shaughnessy would have to be completed in the next six months.

The utilities commission must start work soon to make the system safer in the event of an earthquake, she said.

"I have a state law that obligates me to rebuild the system," Martel said.

Still, Ron Good, executive director of Restore Hetch Hetchy, said he is encouraged by Null's work. With 3.5 million people visiting Yosemite annually, there may be a larger push to pay for Hetch Hetchy restoration.

Good and others maintain that a publicly funded, independent feasibility study is now appropriate to follow up on Null's work.

"She did this work completely independent of us," Good said. "Sarah Null demonstrated it can be done. So the question is: What is it worth to have another Yosemite Valley?"