New $12 million Russian River fish ladder offers glimpse of salmon recovery efforts
A massive concrete structure, built to withstand floods and earthquakes beside the Russian River near Forestville, is the latest step toward restoring the river's beleaguered salmon and steelhead populations.
The 600,000 Sonoma and Marin county residents who get their drinking water from the river paid for most of the $12 million fish ladder, which includes both a video monitoring system so scientists can count the migrating fish and a viewing gallery that will give the public a glimpse as well.
Grant Davis, general manager of the Sonoma County Water Agency, which developed the facility, said it offered a unique, submarine vantage point in California to watch wild salmon make their way upstream.
'This is open-heart surgery that we accomplished in our river system,' he said.
At a formal ribbon-cutting attended by about 150 people Wednesday, state Sen. Mike McGuire hailed the fish ladder as 'a legacy project.'
'The Russian River is who we are in Sonoma County,' he said, noting that the river's once-abundant salmon and steelhead long fed the region's Pomo Indian tribes.
Chuck Bonham, director of the California Department of Fish and Wildlife, lauded the project as a pivotal one for salmon recovery in California.
Describing the annual migration of river-born fish to the ocean and back to their own spawning grounds, Bonham said, 'What journey is more inspiring than that one?'
Sonoma County Supervisor Shirlee Zane said it was 'a heavy lift to get here. You just don't see projects like this today.'
The star attraction of the day — migrating chinook salmon — were largely no-shows.
There likely were scores of the silvery fish swimming slowly past the six large windows built into the underwater viewing gallery, but they were concealed most of the time by brown, silt-laden water following rains that more than doubled the river's flow since last week.
Replays of video footage of the chinook passing through the fish ladder last month, however, showed evidence their fall run was off to a promising start.
The fish ladder was completed in August, in time for the start of the chinook run on Oct. 2, and cameras had captured 531 fish through Oct. 19, said David Manning, the Water Agency's environmental resources manager. The estimated total to date is about 1,000 chinook swimming past the Mirabel facility, he said.
'It's shaping up to be a great year,' Manning said.
On Nov. 2 last year, the count was 124 salmon, and at the same point in 2014, it was 67 fish, he said, adding that the fall run started earlier than usual this year thanks to October rains. It is too soon to know if the annual total will be above the recent annual average of 3,000 fish. Historically, tens of thousands of salmon and steelhead migrated up the watershed to spawn, but those runs dwindled as dams, logging, gravel mining, farming and urban development took a toll on fish habitat.
Recently, drought and poor ocean conditions have also decimated runs statewide. Since 2006, the annual chinook salmon count at Mirabel has fluctuated between 1,125 fish in 2008 to 6,713 in 2012, with an estimate of 4,000 last year, when the fish ladder was under construction.
An abundant fall run indicates that ocean conditions have been good for salmon and could foretell a productive commercial salmon-fishing season next year, said Bob Coey, a National Marine Fisheries Service biologist.
Bodega Bay fishermen have endured two straight meager commercial seasons and a 2015-16 Dungeness crab catch devastated by a prolonged toxic algae bloom. The state's extended drought and unusually warm ocean conditions have depleted California's abalone, urchin, kelp and oyster stocks, as well as salmon and crab.
Sonoma County's ambitious project was prompted by a National Marine Fisheries order in 2008 requiring replacement of the fish screen at the Mirabel installation, where six wells draw water from 100 feet down in sand and gravel and send it to eight North Bay cities and water districts serving Sonoma and Marin counties.
A surcharge built into their water bills contributed $10.5 million to the project, with a state grant covering $1.5 million.
On a bend in the river at Mirabel, an inflatable dam creates a lagoon, and a diversion structure pumps river water into four percolation ponds that help recharge the well field, a critical part of the system, Manning said.
The fish screen on the diversion structure posed a danger to young salmon and steelhead, the federal agency said, and the county opted to build an all-new fish ladder, incorporating a self-cleaning fish screen and affording fish an easier passage around the inflatable dam, which comes down in the winter. It replaced a 1970s-era fish ladder on the west side of the river, leaving a twin model still operating on east side.
The project also included a seismic upgrade of the facility, with 326 columns filled with rock ranging from 30 feet to 90 feet deep in the river bank.
Davis said it would make the fish ladder 'the safest place to be' in an earthquake.
The fortress-like fish ladder, made from more than 2,800 cubic yards of concrete, was built to survive a flood and will be inundated whenever the river hits 20,000 cubic feet per second — as it did last winter during construction. On Tuesday, the flow was about 2,000 cfs, up from 800 cfs a week earlier.
Adding the viewing gallery to the fish ladder was 'above and beyond what was required,' Manning said. It will host visits by about 3,000 school children a year, and the Water Agency will offer free tours of the Mirabel facility from 9 a.m. to noon Nov. 12 and Nov. 18. People can register for one of the tours at www.scwa.ca.gov/tours.