WSDOT to fix Blaine Road culvert
The Washington state Department of Transportation (WSDOT) awarded a $1.3 million construction contract this week to replace a rusting culvert under Blaine Road at Terrell Creek, project that also will improve safety for drivers.
The project involves replacing a rusting steel pipe that blocks fish from moving upstream in Terrell Creek with a wide, concrete box culvert that will be installed to mimic a natural streambed. Puget Sound steelhead, recently listed as threatened under the federal Endangered Species Act, are among the fish that depend on Terrell Creek for habitat.
The completed project should also protect the highway from erosion caused by water flowing out of holes in the culvert and pooling around it. Damaged culverts can create sinkholes and cause roads to crumble.
“The culvert was going to have to be replaced eventually because of rust,” said Marco Foster, a WSDOT engineering manager. “Coupled with the fact that it is a high priority for fish – that’s what got the project funded.”
While working on Terrell Creek WSDOT will take the opportunity to improve driver safety by leveling a section of the road. Cars are obscured from other drivers’ view when they travel through a dip in the existing road.
Nooksack Salmon Association, a Whatcom County-based environmental group, alerted WSDOT that the culvert was failing and created a barrier to fish. As part of the construction contract, NSEA will plant native plants on a half acre along the creek and in a nearby conservation area, to offset the effects of construction.
The existing culvert is a corrugated steel pipe, about 110 feet long and 12 feet in diameter. It hangs almost a foot above the surface of Terrell Creek, creating a difficult jump for fish. The pipe also creates a long, narrow channel, that forces water through quickly and leaves no place for fish to rest in high stream flows,
During high water, sections of broken pipe flip up at the downstream end and close off the pipe completely. Crews have cut away the broken ends to let the water flow through in a temporary fix.
The new concrete rectangular culvert will be 145 feet long, 18 feet wide and 10 feet tall. Stream gravel will be spread along the bottom of the culvert to mimic a natural stream channel.
Ferndale-based Callen Construction won the contract with a bid that was $145,910 less than WSDOT’s engineering estimate. The department will close Blaine Road (SR 548) for up to 43 days starting in August.