|
July 16, 2026
Tunneling for the Coal Creek Sewer Upgrade Project will begin at the Red Cedar Trailhead as early as Monday, July 20. The tunneling machine will run 24/7 to ensure smooth and safe operation. About one mile of the new sewer pipe will be installed by tunneling underground.
What to expect during tunneling:
- Work activity at the Red Cedar Trailhead will continue around the clock during tunneling. The tunneling machine will operate 24/7.
- The tunneling machine will dig deep underground. You may feel small vibrations. King County will monitor tunneling progress to ensure work continues safely.
- There will be construction noise typical to a work site during daytime work hours. The contractor will follow the after-hours permit requirements approved by the City of Bellevue.
- Traffic impacts will include a northbound lane closure on Coal Creek Parkway SE near the Red Cedar Trailhead. The single lane closure will be in effect from 10:30 am to 5:00 am, 7 days a week. This lane closure will not be in effect between 5:00 am and 10:30 am to help reduce morning commute impacts.
- Tunneling is expected to be completed by early 2027.
- The Red Cedar Trailhead is closed. Trail users can access the natural area via the Forest Drive, Red Town, Cinder mine, and other trailheads. Please follow trail detours and stay out of fenced construction areas.
Come chat with us!
Our team will be at the Newcastle Art Fair this Saturday, July 18, from 10 am to 5 pm. Stop by the Avalon Newcastle Commons to chat with us about the project and enjoy the art festivities!
Lane closure on Coal Creek Parkway SE near I-405 through July 24
The construction contractor has a temporary southbound single-lane closure on Coal Creek Parkway SE between 119th Avenue SE and 124th Avenue SE. This temporary lane closure will last through July 24.
What to expect:
-
Traffic impacts: Expect southbound traffic delays. One lane of southbound traffic will be closed. Flaggers will be present to direct traffic. Drivers and cyclists will share a lane when traveling through the work area and are advised to use caution.
-
Work hours: Permitted work hours for the southbound single-lane closure are 6 am to 3 pm, Monday to Friday.
-
Tree removal: The contractor will remove some trees in work areas. Once pipe work is complete, the contractor will restore the work areas.
-
Construction noise: There will be construction noise typical to a work site.
 Note: Lane closure area shown on the map is approximate.
About this project
Construction for King County Wastewater Treatment Division's (WTD) Coal Creek Sewer Upgrade Project began in 2025. It will add wastewater capacity and move the active pipeline away from Coal Creek's environmentally sensitive areas. This project was the first wastewater infrastructure project to earn a Salmon-Safe certification!
After construction, the contractor will restore the Coal Creek Natural Area, parking areas, and affected roadways to protect the creek, trails, and infrastructure. The rebuilt Red Cedar Trailhead will keep the same look-and-feel while enhancing accessibility for visitors of all abilities.
For more information
Visit the Coal Creek project website for the most up-to-date construction information:
Call or email our construction hotline at 425-537-7195 or CoalCreekProject@kingcounty.gov.
Note: This is the King County Coal Creek Sewer Upgrade Project hotline. If there is an emergency, please dial 911. This phone line is for incoming calls only. We will never call you by this number. If you receive a call claiming to be from this number, please be aware it may be a scam.
|
