‘Secret shadow’ of green city

Courtesy Photo

Courtesy Photo

Along with its open-mindedness, embrace of eccentricity and political liberalism, nothing so defines San Francisco as its desire to be green. The Bay Area was the birthplace of environmentalism, and we express our ecological sensibility in everything from locally raised food to hybrid cars to bans on plastic bags.

But there’s one area where some environmentalists believe San Francisco could do better. For more than 80 years, we have stored our tap water in a glacial valley in Yosemite National Park, displacing the ecosystem that used to thrive in one of the most scenic spots in the United States.

“This is like the secret shadow,” said Jennifer Witherspoon, California communications director for the Environmental Defense Fund, which has long favored draining the Hetch Hetchy Reservoir. While she is proud to live in a city that values conservation, Witherspoon said, “I really feel like if San Franciscans want to own our green credentials, this is something we can do.”

But the reservoir’s defenders — among them nearly every public official in  The City — say San Francisco could have no greener water system than what it has relied on since the 1930s. The Hetch Hetchy system brings pristine Sierra snowmelt straight to the Bay Area using the power of gravity. Because the water is so clean, San Francisco avoids expensive and energy-intensive filtration. And on its way here, the water generates hydroelectric power, which keeps street lights on and cable cars running without sending carbon dioxide into the atmosphere.

“It’s about as energy efficient as you’ll ever find,” said Paul Mazza, manager of program development coordination for the San Francisco Public Utilities Commission.

Homes and businesses in San Francisco rely on PG&E for electricity, most of it derived from fossil fuels. But schools, city buildings, the San Francisco Municipal Transportation Agency and San Francisco International Airport are all customers of the SFPUC, which provides hydroelectric power at a much cheaper rate.

“Our customers are all of the services The City provides,” said Barbara Hale, the commission’s assistant general manager for power. “It saves The City a lot of money.”

The commission also generates power through an assortment of solar projects, the largest of which was recently installed on the roof of the Sunset Reservoir. But the capacity for solar power is small — the solar array in the Sunset only generates 5 megawatts on a sunny day, enough to power 5,000 homes. The Hetch Hetchy system generates a maximum of 400 megawatts, which would be reduced by 40 percent if The City did not have the reservoir.

In addition to the solar program, a number of small green-minded projects are included in the commission’s $4.6 billion Water System Improvement Program, an ongoing, bond-funded effort to repair and upgrade the entire water system. Most are centered on water conservation.

This year, the first water-recycling systems will irrigate local golf courses and parks. The commission also has given away rain barrels, gray-water garden irrigation kits and rebates for low-flow toilets so homeowners can boost their own green credentials and reduce their water bills.

The impact of these projects, however, will add up to just 10 million gallons of water a day by 2018. The current system provides up to 265 million gallons a day, 85 percent of which originates with the Tuolumne River, which was dammed to form the Hetch Hetchy Reservoir.

That statistic is not set to change any time soon, despite the hopes of those who want to see the Hetch Hetchy Reservoir drained.

Peter Drekmeier, Bay Area program director for the Tuolumne River Trust, is less worried about the reservoir than about San Francisco’s impact on the river. Although the trust has no formal stance on Hetch Hetchy (“It’s such a loaded issue that once you take a position that’s kind of what you’re about,” Drekmeier said), it is working to get more water flowing freely.

Sixty percent of the river is currently diverted, Drekmeier said, and the salmon population has dropped from 130,000 before the diversions to less than 1,000 in recent years.

While Drekmeier said San Francisco is doing an admirable job of minimizing its water use, the trust is concerned about the SFPUC’s current efforts to increase its Tuolumne River supply by 1 percent, or 2 million gallons a day.

San Franciscans need to be aware of where their water really comes from, Drekmeier said.

“Most people are familiar with the term Hetch Hetchy, but a lot of people don’t know what it is — is it a magical spring up there in the Sierras?” Drekmeier said. “For a San Franciscan, more than half our bodies are Tuolumne River water. We can’t really invest in protecting resources unless we know the source.”

Rent on reservoir costs $30K a year, give or take $5M

The 1913 Raker Act, which gave San Francisco permission to dam the Hetch Hetchy Valley, also locked in fabulously low rent on the site, which belongs to the federal government. But while San Francisco pays only $30,000 a year to store its water in the valley, it also sends up to $5 million a year to the National Park Service to ensure the integrity of the watershed.

“It’s a great working relationship,” said Scott Gediman, a spokesman for Yosemite National Park. “We’re able to get more funding and more rangers just because The City provides that.”

The additional rangers limit access to the area around the reservoir, and they ensure that warm summer days don’t prove too tempting for hikers who might want to take a swim.

The Park Service also is working with The City to mitigate the environmental impact of the dam, including by changing the pattern of water release to mimic natural spring flooding conditions. It’s a move the Park Service says will revive wildlife along the upper Tuolumne River.

While some previous stewards of Yosemite admit that they resented the reservoir, officially the Park Service is resigned to its continuing existence.

“The Raker Act authorized it and it’s there,” Gediman said. “Regardless of anyone’s feelings, it’s something that is there.”


Power plus

San Francisco government’s use of power from the Hetch Hetchy system and what it would cost to get it elsewhere:

  • 1.7 million megawatt hours: Hydropower generated by the entire system each year
  • 1 million MW hours: Hydropower that would be generated without the Hetch Hetchy Reservoir
  • 415,000 MW hours: Provided at a discount to The City
  • $41 million: Cost to replace power that would be lost without Hetch Hetchy reservoir

Source: SFPUC


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