SW Cemetery Road Drainage Improvement Project
Work began in fall 2024
King County will realign the ditch on SW Cemetery Road on Vashon Island to improve drainage and reduce flooding. Photo: Google Maps
Status update
November 22, 2024
Crews are reducing traffic to a single lane on SW Cemetery Road between Beall Rd SW and 87th Ave SW from Mon. Nov. 4th to Fri. Dec. 6th, from 8 a.m. to 3 p.m. each day for drainage improvement work in the public right of way. No weekend work is scheduled. Flaggers are directing alternating two-way traffic. All vehicles have access through the work zone and travelers should expect minor traffic delays.
Project overview
When it rains a lot, the south side of SW Cemetery Road between 87th Avenue SW and Beall Road SW/91st Avenue SW on Vashon Island often floods. The water from flooding often extends to private property. This makes it hard for people traveling to and from Maury Island or the Vashon Island North-End Ferry Terminal. To fix this, the county plans to improve the drainage by replacing the old driveway culverts and fixing the roadside ditch. We will move the ditch further from the road and remove some trees that have grown in it. These trees cause problems because their roots, leaves, and branches clog the culverts and block water flow. The project will also add a five-foot-wide gravel shoulder to make it safer for people walking along the road.
What to expect during construction
- Some trees will be removed within the county right-of-way, next to the drainage ditch, in September/October 2024.
- There will be single-lane restrictions on SW Cemetery Road between 87th Ave. SW and Beall Road SW for eight (8) weeks, starting as soon as October.
- Flaggers will direct two-way traffic weekdays from 7:30 a.m. to 4 p.m. daily.
- Driveway access will be maintained throughout construction as much as possible.
Project location
The project is located on SW Cemetery Road between Beall Street SW and 87th Avenue SW on Vashon Island. View larger image (900KB)
Existing conditions
Tree roots, overgrown vegetation, and fallen branches along the roadside and in ditches clog the drainage ditch, which can clog drainpipes and lead to flooding. Photo: Google Maps
Dense vegetation and tree roots restrict the amount of water that can flow along the ditch and through nearby culverts. Photo: Google Maps
The project will move the drainage ditch to remove trees and improve drainage. The ditch will be relocated to its original location at the end of the project. The County will also add a gravel shoulder to improve safety for pedestrians. Photo: Google Maps
Frequently asked questions
The trees should have been removed when they began to grow, but a decision was made at the time to keep them. Their size and proximity to the road prevent a ditch or piped stormwater system from functioning properly.
Unfortunately, the way the ditch has filled in over time, including the growth of the trees, changed the elevation along the path for the water to flow. This means that in this stretch, the water must flow uphill to reach the drainage pipe. There is too much debris to remove simply by clearing out the drainage ditch or mowing. Our project engineers are confident that this will be a long-term solution to the drainage problem.
King County Road Services is working to keep neighbors up to date. We will do the following before and during construction:
- Update the project website regularly.
- Provide updates on X/Twitter (@KCroads) and on MyCommute (kingcounty.gov/MyCommute).
- Send email notices (sign up for Road Alert email notifications).
- Have a flyer available to people living near the work area with complete construction timeline and closure details.
- Speak with community groups upon request; please contact abresslour@kingcounty.gov to schedule a meeting.