Kapowsin Tributary Culvert Replacements

Land Owner:  IP Pacific Timberlands

Location:       Tributary to Lake Kapowsin, Pierce County, Washington  

Sponsor:        Pierce County Conservation District   

Contractor:    CeCon Corporation, Tacoma, WA

Project Cost:  $44,000 (Both culverts)   


Project Summary: Chinook Engineering provided design assistance and construction management for this project involving the replacement of two undersized culverts on a tributary to Lake Kapowsin. The first culvert was replaced with a new 7 foot diameter pipe at a zero percent slope beneath the IP Pacific mainline logging road. The second culvert, further downstream on an adjacent service road, was replaced by a 9 foot diameter pipe installed on a 3 percent slope using the WDFW stream simulation design approach. The original culvert at this location was perched and therefore a complete barrier to upstream fish migration. With larger pipes in both locations and a resultant reduction in water velocities, fish access to upstream habitat is now possible. 







First section of the 7 foot diameter pipe be 

lowered into the trench on the mainline














Upstream photo of completed mainline 
















First section of the 9 foot diameter pipe be 

lowered into the trench on the 

spur road crossing.












Downstream photo of completed 

spur road crossing











Copyright, 2008. Chinook Engineering

For question or comments regarding this page please contact: jay@chinook-engineering.com

  Last modified: March 21, 2008   

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