Fall 2005
Vol. XIV, No. 4

Deadwood Creek Fish Passage Enhancement Project

Culvert
Improving access for salmon
in Deadwood Creek.
The RCD has just completed a fish passage improvement project on Deadwood Creek in Lewiston. The goal of the project is to improve access to 3 miles of spawning and rearing habitat for native salmon. Funding for the work was provided through the Five Counties Salmonid Conservation Program. The 9- foot high by 120-foot long culvert, located at Trinity Dam Boulevard and Deadwood Road, near the fish hatchery, was identified by the Program as being a partial barrier to fish migration. Fish have had difficulty trying to swim up the 120-foot length during the high flows the creek sees in the late fall and winter period when the adult fish attempt to migrate upstream to their spawning habitat. The culvert was retrofitted with baffles that help break up the flow of water the same way that large boulders would in a natural creek bottom, providing the Coho, Chinook and Steelhead with greatly needed resting areas.

The project consisted of constructing a diversion dam 80 feet upstream of the culvert diverting the water into a 200-foot long, 15-inch diameter PVC pipe that was temporarily mounted to the inside of the culvert. Once the diversion pipe was in place, biologists from the California Department of Fish and Game electrofished and removed any juvenile salmon in the creek between the diversion dam and the culvert entrance. Six metal plates, or baffles, were welded to the bottom of the culvert about 20 feet apart. Metal reinforcing bars (rebar) were used to create a grid that serves to tie the baffles together and provide support and strength for the concrete that was placed in the culvert bottom and sides. The function of the concrete is to help keep the baffles in place, protect them from boulders washing downstream and protect the culvert bottom, which is rusting through in places, adding many additional years to the life expectancy of the culvert.

The RCD would like to acknowledge the assistance for work on this project provided by the CA. Dept. of Fish and Game, Natural Resource Conservation Service, Trinity County Road Department, and the local businesses, Concrete Aggregate Products and Cougar Concrete Pumping. The Five Counties Salmonid Conservation is Managed by Mark Lancaster and his staff in the Trinity County Planning Department.

Going In
Diversion pipe, rebar, and baffles
inside culvert.

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