For the first time since the 1950s, Chinook salmon are once again swimming upstream in Alameda Creek, and they did not waste any time doing it.
Earlier this month, California Trout (CalTrout) and Pacific Gas & Electric (PG&E) completed a major fish passage project that removed the final unnatural barrier on the creekâs mainstem. Just days later, biologists spotted two Chinook, up to 24 inches long, above the former blockage.
Alameda Creek is the largest local tributary feeding the San Francisco Bay and was once home to thriving runs of Chinook and steelhead. Decades of urbanization, dams, and an ill-placed gas pipeline had cut off more than 20 miles of high-quality spawning habitat. That pipeline, which sat atop a concrete erosion mat, protruded into the creek and prevented fish from passing during most flows.
The solution required a major engineering effort. PG&E lowered the pipeline 20 feet beneath the creek bed and moved it 100 feet downstream. This allowed crews to remove the concrete mat, regrade the stream channel, and restore native vegetation. With the obstruction gone, Chinook immediately began reclaiming habitat that had been inaccessible for more than 70 years…