Ecological rewind - Page 4

Environmentalists want to tear down O'Shaughnessy Dam and restore the Hetch Hetchy Valley, but does their plan hold water?

Kolana Rock towers above Hetch Hetchy Reservoir in Yosemite National Park.


In addition to capturing the flow of pristine Tuolumne River water that eventually makes its way into the city's plumbing network, O'Shaughnessy Dam is a key component of the SFPUC-owned hydro-electric system, which produced 1.7 billion kilowatt hours of power last year with no greenhouse gas emissions.

If efforts to advance the cause of a public power system resurfaced in San Francisco, having the full capacity of the Hetch Hetchy hydro-electric generation in place would be vital. Juice for city streetlights, Muni's light rail cars, the chandeliers adorning the Board Chambers in City Hall, and countless other municipal uses are derived from this gravity-fed system, which provides roughly one-fifth of San Francisco's overall energy needs.

City departments pay three or four cents per kilowatt-hour, less than what it costs to generate the power. If all the hydro-electric power were eliminated and substituted with PG&E power, the city would get pinned with $32 million in additional costs annually, and its carbon footprint would expand by more than 900 million pounds of greenhouse-gas emissions, according to the SFPUC. However, a technical report produced by the Environmental Defense Fund suggests the city would only suffer a 20 percent decline in the hydro-electric output, since operations at other SFPUC reservoirs would continue.

The hydro-electric system also generates revenue through the sale of excess power to Turlock and Modesto irrigation districts, but that would come to an end if the generation capacity fell by 20 percent. Restore Hetch Hetchy estimates this loss to be around $10 million annually.

"Whenever we sell the power to Modesto and Turlock, that revenue then goes to fund programs like GoSolarSF, and all of our energy-efficiency retrofits of municipal facilities," Jue explains. If the city lost its ability to sell off this excess supply, "We would no longer be getting power revenue at all, which we're using to help fund community choice aggregation."

Fraught with problems as it is, the city's effort to launch a community choice aggregation program offering residential customers an alternative to PG&E nevertheless holds promise as a powerful green shift for a major metropolitan hub. For all the ecological benefits to Yosemite, restoring Hetch Hetchy could wind up undercutting the fledgling green power initiative, and the upshot would be a boon for PG&E. Coupled with the fact that ceding control of the valley back to the National Park Service could strip the city of its mandate for public power, the utility giant would benefit tremendously from this plan.

All of this makes it somewhat surprising that District 5 Sup. Ross Mirkarimi, a longtime champion of the cause of public power, appointed Marshall to serve on the SFPUC Citizens Advisory Committee, a move that rankled SFPUC staff.

"I've known Mike many years and have found him to be whip smart when it comes to complicated policy issues," Mirkarimi told the Guardian when asked about this. "He knows that I am an unwavering supporter for public power and that I'd hope his advocacy on the SFPUC continues to advance and innovate our locally-driven clean energy objectives."



The concept of bringing back Hetch Hetchy Valley originated with the Sierra Club in 1999, and several mainstream environmental organizations have lent support for the cause although few have made it a high priority. Nevertheless, there's plenty of financial backing and support from key political players to keep the vision alive.

Democratic County Central Committee Chair Aaron Peskin, a member of Restore Hetch Hetchy's national advisory board, told me he's been active with the group for at least a decade, making him a rare exception among the city's political leaders.