Alert the fish: Two older dams demolished on Alameda Creek
S.F. water agency takes initial steps to restore salmon, steelhead runs
By Douglas Fischer, STAFF WRITER, Inside Bay Area
Friday, September 22, 2006
SUNOL — It wasn't Hetch Hetchy, but a dam is coming down.Two, actually.
The San Francisco Public Utilities Commission, the agency piping water from the Hetch Hetchy Reservoir in Yosemite National Park to 2.4 million customers in the Bay Area, today will blast to smithereens the last pieces of two antiquated dams along Alameda Creek.
Their removal from the winding canyon high above Fremont will open nearly 20 miles of river to migrating steelhead and salmon, though further obstacles remain downstream before ocean-going fish can resume their migration to the sea.
The pair of dams were once a key part of the region's water supply. They were rendered obsolete nearly 70 years ago when the San Francisco Public Utilities Commission completed the O'Shaughnessy Dam and buried Yosemite's Hetch Hetchy Valley beneath 300 feet of water.
"It's a beautiful day to say goodbye to a dam," said Jeff Miller, director of the Alameda Creek Alliance, which has spent 10 years trying to restore the creek. He spoke during a media tour Thursday atop a pile of rubble that was once a 26-foot-tall wall of concrete across the river.
"It's kind of staggering to see this without the Sunol Dam."
For the utility, the decision to remove the two dams was a no-brainer, said SFPUC general manager Susan Leal, even if the removal — from conception to permitting to demolition — took almost a decade. Demolition costs alone totaled $1.8 million.
"This is a new PUC, and where we can make improvements, we have to step up," Leal said.
The Niles Dam first went up in 1841, built in the middle of Niles Canyon by the brother of Spanish Gen. Mariano Guadalupe Vallejo to power a flour mill. In 1887, the Spring Valley Water Co. — predecessor to the SFPUC — topped Jose de Jesus Vallejo's work with rocks and concrete. Thirteen years later and a few miles upstream it built the larger Sunol Dam to bring the creek's waters to San Francisco.
Both have been in a slow state of decline since 1934, when the Hetch Hetchy system started delivering Sierra Nevada water to the city. Environmentalists have lately called on SFPUC to restore the Hetch Hetchy Valley, a notion the agency has vigorously resisted.
By Wednesday at the former Sunol Dam site, the creek was already eating away at a century's worth of accumulated sediment. That muck, backed up for at least a few hundred yards, will gradually wash downstream. In a year or two or three, the stream should look as if the dam was never there, various authorities claimed.
"One good winter," promised Miller.
But it will be some time before ocean-going steelhead and salmon return. A weir near the BART tracks in Fremont, near the creek's mouth, blocks any migration, as do three inflatable rubber dams operated by the Alameda County District. And two miles upstream, a Pacific Gas & Electric Co. pipe blocks passage to promising spawning grounds.
But there is progress: One of the three rubber dams will be demolished next summer. PG&E is working on a way to get fish around its pipe. But getting fish past the weir is a $4 million to $5 million problem, Miller estimates.
That's money well spent to restore a steelhead run that was snuffed out in the 1960s when the lower dams went in. "The first time (people) see one of these fish, they're kind of stunned by how big and alive they are and how intent they are to get up this creek," Miller said.
"We'll never get a historic run (back)," he acknowledged. "The goal is to get a self-sustaining, healthy population."
It will be even longer before the Hetch Hetchy Valley and the Tuolumne River see natural flows. The reservoir is the linchpin of San Francisco's water system and demolishing the 430-foot-tall dam, restoring the valley and obtaining other water storage could cost more than $1 billion.
And so on Wednesday the brief and uncomfortable silence could be expected when a reporter asked if the agency's work on Alameda Creek might just be a warmup for a more ambitious undertaking in Yosemite.
Perhaps 70 years after the O'Shaughnessy Dam is rendered obsolete?
Yes, the officials agreed, maybe then.
Contact Douglas Fischer at dfischer@angnewspapers.com.
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