PALO ALTO -- The hard-luck steelhead trout of San Francisquito Creek will have one less obstacle to surmount once the storms of winter set the stage for their annual spawning runs.

A construction team has removed a century-old concrete barrier from a section of the creek in El Palo Alto Park on the Palo Alto-Menlo Park border, restoring the streambed to a more natural course. The roughly 40-foot-wide structure, known as a weir, had acted at times as a dam, trapping the federally threatened fish on either side.

Jared Blumenfeld, regional administrator for the U.S. Environmental Protection Agency, joined a throng of government officials and local conservationists Thursday for a celebration of the project's completion. The $309,400 initiative is among 48 projects to receive more than $28 million in funding from the EPA since 2008 to protect and restore San Francisco Bay.

"Small things can make a really big difference," said Blumenfeld, noting the weir removal will enable steelhead to gain better access to many miles of habitat, particularly on the Los Trancos Creek and Bear Creek tributaries.

The barrier was built long ago to support a two-story retaining wall that prevents the southern bank of the creek from eroding. The wall bolsters two bridges that cross the creek, one for pedestrians and the other for Caltrain, and protects the root system of "El Palo Alto," the historic redwood from which the city of Palo Alto derived its name.


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Crews under the leadership of the San Mateo County Resource Conservation District replaced the weir with rocks and boulders that will keep the retaining wall secure while allowing steelhead to move much farther into the San Francisquito Creek watershed, which empties from the Santa Cruz Mountains above Woodside and Portola Valley into the bay.

Central California Coast steelhead were once abundant in ocean and bay streams from Sonoma County to Santa Cruz, but their numbers plunged in the 20th century due to habitat degradation. San Francisquito is deemed an "anchor habitat" for the species, whose population in bayside streams has been decimated.

The segment of San Francisquito Creek at El Palo Alto Park is mostly dry now, but it swells once winter storms arrive. The weir had its greatest impact during low to moderate flows, blocking adult steelhead charging up the creek to spawn and trapping juvenile fish making their way down to the bay.

There is still more that can be done to help the steelhead here, said Jerry Hearn, a Portola Valley resident who has been working on restoring the San Francisquito watershed for two decades. The biggest obstacle remains Searsville Dam in Stanford University's Jasper Ridge Biological Preserve. The university, beset by an environmental lawsuit, is studying whether to remove or modify the dam.

Hearn, 68, said it is gratifying to see the weir torn away some decades after he and fellow conservationists first proposed it. Just a little boost, he said, can mean a lot to the dogged steelhead.

"The fish can get astoundingly far up those canyons," he said. "It's all about energy expenditure as you go upstream."

Contact Aaron Kinney at 650-348-4357. Follow him at Twitter.com/kinneytimes.