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141st Avenue SW Culvert Replacement Project
Project anticipated in late summer or early fall 2025
The existing pipe under the road at 141st Ave SW on Vashon Island is old and failing and needs to be replaced.
Status update
April 2025
Construction for this project will require a full road closure and is scheduled to last eight weeks. It is anticipated to begin in late summer or early fall 2025. If the schedule changes to be earlier in the summer, Road Services is aware of the Garden Tour and will ensure access during this event.
Please check this website and sign up to receive email notifications about the project by emailing abresslour@kingcounty.gov.
Project overview
Under 141st Avenue SW between SW 216th St and SW 220th St, there is an old and rusted pipe that must be replaced in the ravine. The pipe is getting plugged and not allowing water to flow through the culvert as it should. Sections of the pipe have fallen off causing the west side of the road to sink and slope outward.
A new larger diameter longer pipe will replace the existing culvert, and the road will be reconstructed at the pipe crossing. This work requires crews to close a section of road for up to eight weeks in late summer or early fall 2025.
A closer look at the existing metal pipe under the road at 141st Ave SW.
To replace the culvert, crews will:
- Temporarily regrade the road to a lower elevation to allow safe equipment access to the ravine.
- Excavate to remove the existing road and pipe.
- Once the pipe is removed and the ground has been stabilized, crews will replace the pipe with a much wider and longer heavy-duty plastic culvert.
- Crews will then rebuild the road with wider slopes made out of rocks.
- Next, the road will be lifted and slopes built out of sturdy fabric, rocks, and gravel.
- Finally, the road will be 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.
What to expect during construction
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Work hours: We expect the crew to be on site Monday through Saturday during daytime hours. Occasional Sunday work is possible. Work could begin as early as 7:30 a.m. and last as late as 4 p.m. Occasionally the work could continue later in the day. The road will reopen at night and for a lunch break mid-day.
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No thru access during work hours: 141st Ave SW between SW 216th St and SW 220th St, will be closed to all vehicles, including emergency responders, bicycles, and pedestrians during work hours. The work area will re-open to thru traffic at least once during the day. There is no detour route. The project team will communicate with residents and first responders about the opening schedule prior to construction. If there is an emergency, crews will be able to open to road, but please limit these requests to true emergencies as it could extend the length of the project.
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During construction, travelers can expect a temporarily steeper and unpaved driving surface when the road is open.
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Please plan ahead: If you know you'll need routine daytime access during work hours, you may want to arrange to stay elsewhere during the project as the road can only be opened for true emergencies.
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Delivery services: US Mail, deliveries, and garbage/recycling may be restricted or unavailable during construction. Residents should arrange to pick up mail at the Post Office and have packages delivered outside of project work hours.
Frequently asked questions
The road will be slightly wider once complete. Crews will add a small rock shoulder to both sides of the new road. The new road will be the same elevation as the existing road.
Pictured above, crews built a rock slope on Cunliffe Road SW in 2024 using a similar technique. The project on 141st Ave SW will look similar once complete.
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Update the project website regularly.
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Have an online community meeting prior to the project.
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Provide updates on X/Twitter (@KCroads) and on MyCommute (kingcounty.gov/MyCommute).
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Send email notices (sign up for Road Alert email notifications).
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Have a flyer available to people living near the work area with complete construction timeline and closure details.
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Speak with community groups upon request; please contact abresslour@kingcounty.gov to schedule a meeting or to join the email outreach list.
