A three-day storm has pumped up drought-stricken creeks throughout the Russian River watershed, opening a watery door to the winter spawning run of imperiled coho salmon and serenading rural residents with the sound of rushing water.
All 22 coho spawning tributaries of the Russian River were open Monday, and eight adult coho had made it up Dry Creek to the fish hatchery at Warm Springs Dam, proof that the critical run was under way, said Eric Larson, environmental program manager for the state Department of Fish and Wildlife Bay-Delta Region.
Creeks that were cut off from the river, with a trickle of water at best between shallow pools, had fast-moving, chocolate-brown water on Monday after the storm dropped nearly 1.5 inches of rain on Santa Rosa over the weekend and rain kept falling Monday.
“We’re very excited,” Larson said, adding that scientists were also anxious to see how many coho will ultimately return to spawn in the creeks where they hatched three years ago.
This season’s run of the endangered species is critical because it is the first generation of coho born during California’s drought, which has threatened a broad effort, dating back to 2001, to bring coho salmon back from the verge of extinction.
About 550 coho returned during the winter of 2012-13, marking the program’s best-ever result, but the number has steadily declined since, with about 200 returning to the Russian River basin last winter. Spawning opportunity was limited to the creek flows generated by the season’s two major storms in December 2014 and February 2015, Larson said.
Coho salmon spend the first year of their life in fresh water, then migrate to the ocean and return typically two years later as adults to spawn and complete their life cycle. Decades ago, up to 500,000 coho spawned in Northern California river systems, dwindling to about 5,000 by the mid-1990s, when scientists realized the need for human intervention, including habitat restoration and a hatchery breeding program.
As Sonoma County creeks dwindled this past spring, becoming disconnected from the river, that intervention took the form of a massive fish rescue of about 3,000 young coho from Porter, Felta, Dutch Bill and Mill creeks, Larson said.
About 500 fish were transplanted to lower reaches of the creeks, and about 2,500 juvenile coho were taken to the hatchery below Warm Springs Dam at Lake Sonoma.
Also starting this past spring, the State Water Resources Control Board launched an aggressive and controversial campaign to preserve flows in four critical coho streams, ordering thousands of rural landowners to curtail outdoor water use and report their use of stream and well water to the state.
The orders, still in effect, applied to residents and businesses in the watersheds of Dutch Bill and Green Valley creeks in the west county, Mark West Creek north of Santa Rosa and Mill Creek west of Healdsburg.
Last week, officials finished returning the 2,500 young coho to the streams where they had hatched and where they will likely remain until spring, Larson said.
And now, to the delight of biologists and residents, the creeks are again open for the adult coho.
Dutch Bill Creek swelled to 30 inches deep Sunday night before dropping to about 20 inches Monday morning at a point near Alliance Redwoods on Bohemian Highway, said Gary Helfrich, a Camp Meeker Recreation and Park District board member.