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141st Avenue SW Culvert Replacement Project
Construction completed in summer 2025
The new, 80-foot-long plastic pipe has been installed beneath the road. Crews built back the road and hillside, and completed the project with a fresh overlay of pavement in August, 2025.
Status update
August 7, 2025
141st Ave SW reopened to traffic on August 6, 2025, after the culvert replacement project was completed. The previous 18-inch metal pipe that was 51 feet long was replaced with a heavy-duty plastic pipe that is 24 inches in diameter by 80 feet long. The road was rebuilt and is much sturdier and slightly wider with fresh pavement.
You’ll still see some members of our team at 141st Ave SW from time to time for regular checks of the new system by our project team and planting, seeding, and landscaping.
We know this project was impactful to the neighborhood and we are thankful for the partnership and patience of the community.
Project overview
Under 141st Avenue SW between SW 216th St and SW 220th St, there was an old and rusted pipe in a ravine that needed to be replaced. The pipe was getting plugged and didn’t allow water to flow through the culvert as it should. Sections of the pipe had fallen off causing the west side of the road to sink and slope outward.
A new larger diameter longer pipe replaced the previous culvert, and the road was reconstructed at the pipe crossing. This work required crews to close the section of road for five weeks.
A closer look at the previous metal pipe under the road at 141st Ave SW.
To replace the culvert, crews:
- Temporarily regraded the road to a lower elevation to allow safe equipment access to the ravine.
- Excavated to remove the existing road and pipe.
- Once the pipe was removed and the ground was been stabilized, crews replaced the pipe with a much wider and longer heavy-duty plastic culvert.
- Once the pipe was removed and the ground was been stabilized, crews replaced the pipe with a much wider and longer heavy-duty plastic culvert.
- Next, the road was lifted and slopes built out of sturdy fabric, rocks, and gravel.
- Finally, the road was paved and the road slightly widened by adding a small rock shoulder to both sides.
Project location map
Larger view of map (262KB)
The 141st Ave SW Culvert Replacement project is located on a sole access road on the west side of Vashon Island, Washington.
Frequently asked questions
The road is slightly wider. Crews will add a small rock shoulder to both sides of the new road. The new road is the same elevation as the existing road.
Photos
141st Avenue SW awaits paving after the replacement of an underground pipe. Crews rebuilt the road to be stronger and slightly wider.
Using a large trench box, crews installed the new much larger and longer sturdy thick plastic pipe under the road.
The existing pipe under the road at 141st Ave SW on Vashon Island is old and failing and needs to be replaced.
In early December 2024, Crews added new asphalt as a temporary repair until the permanent work is scheduled.