Langlois Creek

LOCATION

Carnation, Washington

DESCRIPTION 

Our team served as the General Contractor to WSDOT for the installation of a new fish passage for Langlois Creek under SR 203 in Carnation.   The new 19-foot-wide concrete culvert (i.e., new fish passage) replaced the existing 30-inch diameter culvert.  The new (and larger) culvert improved stream flow for local salmon and steelhead, opening up about five and a half miles of new fish spawning habitat.

SCOPE OF WORK 

We were responsible for clearing and grubbing, stream diversion, dewatering, lowering of the existing watermain, removal of existing culvert, installation of the new fish passage, guardrail, fencing, asphalt paving, channelization, and stream restoration.

PROJECT HIGHLIGHTS

• Surrounded by sensitive wetlands and located on SR 203, our team had to implement a traffic detour for the full closure of SR 203 for 56 consecutive hours to remove the existing fish passage and construct the new one
• Extensive dewatering was required due to the high groundwater table
• Lowered the watermain approximately 12’ deep
• Installed a 19’ wide x 9’ deep x 44’ long precast concrete box culvert under SR 203