SR 203 - Langlois Creek - Fish Passage

Project news

  • A full closure of SR 203 between Northeast 32nd Street and Langlois Lake Road is scheduled from 8 p.m. Friday, Sept. 14 to 6 a.m. Monday, Sept. 17. The highway will be closed to all traffic while crews install a culvert. 
  • This project was awarded to Northwest Construction, Inc.
  • Construction is scheduled to begin in summer 2018.
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WSDOT will replace the existing narrow round culvert channeling Langlois Creek with a large box culvert in summer 2018. The creek crosses under State Route 203 between Northeast 32nd Street and Langlois Lake Road in Carnation. An 18-foot wide box culvert will be installed to improve stream flows for migratory steelhead, cutthroat and coho. This project will open up almost 5.5 miles of additional fish habitat when completed.

The work will require a full three-day closure of SR 203 at the project site. There will be about a 4.5-mile detour due to the closure.

Why is WSDOT replacing the culvert next to SR 203 at Langlois Creek?
The existing 30-inch diameter culvert is a barrier to fish. Water flows are occasionally too low or strong for fish to navigate upstream. Installing a larger box culvert will allow the creek to flow more naturally under the highway and improve fish habitat in the area. The fish passage project is one of about 1,000 culverts across the state that are mandated to be replaced. In 2013, the U.S. District Court for Western Washington ruled that the state must remove culverts that block fish passage under state highways.

The End Result
The creek will be restored to a more natural free-flowing state resulting in improved fish passage for local migratory fish. This will bring the stream crossing into compliance with the U.S. District Court ruling.

Needs & benefits

  • This project will improve fish passage and open up almost 5.5 miles of additional fish habitat.
  • The work will help WSDOT comply with the U.S. District Court ruling regarding fish passage.


Winter 2017: Project advertised for competitive bidding. 
Summer 2018: Estimated construction start.
Fall 2018: Construction will be completed.


Financial Data for PIN 120304F
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $1,173
CWA $404
Total $1,577


Marqise Allen
WSDOT communications
Phone: 206-440-4699

WSDOT will replace a culvert near SR 203 just south of Carnation.

WSDOT contractor crews will replace the concrete culvert that channels Langlois Creek under SR 203.
Langlois Creek flows through a narrow round concrete culvert adjacent to SR 203 in Carnation.

View more photos