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Creek fish passage becomes issue with Soscol Junction traffic project

Creek fish passage becomes issue with Soscol Junction traffic project


Drivers aren’t the only ones who face difficulties getting through the Soscol Junction area at Highway 29 and Highway 221 – so do steelhead and that poses potential challenges for a key county transportation project.

The trout are in Suscol Creek, which near Soscol Junction passes through an existing Highway 29 bridge culvert that is considered a fish-blocker. State law requires Caltrans to fix fish passage barriers when improving highways.

Doing so could cost $10 million, a Napa Valley Transportation Authority (NVTA) report said. It could potentially – but not necessarily – delay a $40 million Soscol Junction project targeted to begin in a couple of years to ease Highway 29 congestion.

Caltrans will bear the added cost and might do the Suscol Creek fish passage fix as a separate project to avoid Soscol Junction delays, the report said. (The creek is spelled “Suscol” and the Junction “Soscol.”)

“We are working through it, and we’ll find a solution so it doesn’t stall the project,” NVTA Executive Director Kate Miller said.

The signalized intersection at Highway 29, Highway 221 and Soscol Ferry Road is targeted for this long-awaited, congestion-busting project. Caltrans in a 2015 study reported evening rush-hour traffic delays of almost two-and-a-half minutes.

If all goes as planned, Highway 29 drivers will no longer be backed up on the Butler Bridge staring at the Grapecrusher statue as they wait to move. They’ll pass over Soscol Junction on an elevated highway section with no traffic signal.

Highway 221/Soscol Ferry Road will pass underneath this elevated section. Two roundabouts along this stretch – not on Highway 29—will regulate through traffic and traffic getting on and off Highway 29.

Caltrans officials at Wednesday’s NVTA Board of Directors meeting showed a video simulation of how Soscol Junction is supposed to work. Drivers, cyclists and pedestrians all did just fine in an animated scenario, navigating the roundabout with ease, with no big backups.

Those concerned about the roundabouts might note that Healdsburg drivers are faced with a new, five-way roundabout with train tracks passing through it, Calistoga Mayor and NVTA Board of Directors Chair Chris Canning said.

“They all figure it out,” he said.

Caltrans could release environmental documents for the Soscol Junction project this fall for comments by the public.

Meanwhile, there’s the fish passage problem at the nearby Highway 29 bridge over Suscol Creek. Steelhead must navigate a 1915 arch culvert and later-date extensions and additions that together total 202 feet.

Only the strongest steelhead swimmers can make it through at certain flows, according to a 2011 study done by the Napa County Resource Conservation District for the California State Coastal Conservancy.

Senate Bill 857, signed into law in 2005 by then-Gov. Arnold Schwarzenegger, requires Caltrans to remove fish barriers when building new projects. The bill sponsor said Caltrans is the largest fish barrier owner in the state.

Suscol Creek is about 600 feet southeast of Soscol Junction intersection. But NVTA Program Manager-Engineer Sanjay Mishra said the planned entrance to Highway 29 from Soscol Ferry Road will require widening the Suscol Creek bridge by 14 feet.

Miller elaborated to the NVTA Board of Directors.

“Actually, it’s arguable whether or not we touch the stream,” Miller said. “But the regulatory agencies have sort of targeted this project. It’s pretty high profile, very high profile for Napa.”

And the steelhead is a high-profile fish. Central California Coast steelhead have been listed as “threatened” under the federal Endangered Species Act since 1997. The fish spend much of their lives in the ocean and return to fresh waters to spawn.

The National Oceanic and Atmospheric Administration Fisheries in 2015 released a report looking at ways to increase steelhead numbers in the state. Among its long list of priority actions is creating appropriate fish passage on Suscol Creek at Highway 29.

Once beyond Highway 29, steelhead can continue up Suscol Creek to the Suscol Headwaters Preserve owned by the Napa County Regional Park and Open Space District. This area is one day to be a park with hiking trails.

The Coastal Conservancy provided a $400,000 grant toward the purchase of the second phase of Suscol Headwaters. An agency report said that, among other things, the preserve includes prime steelhead habitat.

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Napa County Reporter

Barry Eberling covers Napa County government, transportation, the environment and general assignments. He has worked for the Napa Valley Register since fall 2014 and previously worked 27 years for the Daily Republic of Fairfield.

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