North Mercer Island/Enatai sewer upgrade

General project updates

April 22, 2025

Project-wide updates

Construction is underway across north Mercer Island and southwest Bellevue. To keep everyone safe, follow all instructions from crews and signage and use caution as you travel through work areas.

King County’s contractor has been approved to continue working extended Saturday hours from 7 a.m. to 7 p.m. in all project areas across north Mercer Island. These extended hours began in June 2024 and are now approved through August 30, 2025. For more information, check out our March project-wide notification.

Please note that the texting option on our hotline is not currently available. To connect with us, please call our hotline at 425-305-3578 or email NMESewer@kingcounty.gov.

Construction activity in Mercer Island*

Area 1. North Mercer Pump Station: Testing for the new fire alarm system in the pump station building has been postponed. We will provide an update when the work has been rescheduled. Neighbors near the pump station can expect periodic noise and lights from the pump station building while testing is in progress. For more information, check out the February Area 1 notification.

Area 2. North-central Mercer residential streets: King County's contractor is expected to begin pipe repair work on North Mercer Way, between 80th Avenue Southeast and Island Crest Way in May. To ensure safety, road closures will be in place on North Mercer Way between 80th Ave S.E. and Island Crest Way and at 81st Ave Southeast and North Mercer Way. Residential access will be maintained. Please travel slowly through the area and follow all signs, traffic control signals, and directions from crews. For more information, check out the April 21 Area 2 notification.

Area 3. North Mercer Way: Crews installed pipe and paved North Mercer Way in 2023 and installed accessible curb ramps in spring 2024. For more information, check out past Area 3 updates.

Area 4. I-90 Trail: The I-90 Trail between Island Crest Way and Shorewood Drive and between Fortuna Drive and Southeast 35th Street is closed for repair work. Please follow the posted trail detour route along North Mercer Way. Drivers should use extreme caution while moving through this area. For more information, check out the March Area 4 notification.

The I-90 trail remains closed between Southeast 35th Street/North Mercer Way and Southeast 35th Place/East Mercer Way for sewer construction in the area. Trail users should follow the posted detour route:

• Trail detour map between S.E. 35th St and S.E. 35th Pl. This takes trail users on East Mercer Way, Southeast 36th Street, and North Mercer Way, before connecting back to the I-90 trail. Drivers, please drive slowly and watch for cyclists on the roadway.

For more information, check past Area 4 updates.

Area 5. 90th Pl S.E.: Paving on 90th Pl S.E. is complete. Crews continue work on the odor control structure in the cul-de-sac at the top of 90th Pl S.E. For more information, check past Area 5 updates.

Area 6. NE Mercer Island:

Fruitland Landing: Crews completed coating activities for the maintenance hole on 97th Avenue Southeast. Fruitland Landing park remains closed while crews upgrade Lift Station 11 and prepare to upgrade the pipes in the roadway.

S.E. 35th Pl: Crews are completing the installation of the retaining block wall around the odor control structure at the southwest corner of East Mercer Way and Southeast 35th Place. Brief delays of a few minutes may occur when entering or exiting S.E. 35th Place due to construction equipment moving through the work area. Please drive carefully and follow all posted signs and instructions from crew members. For more information, check out our March Area 6 notification.

Mercer Island Boat Launch: Crews have completed work to install a sidewalk ramp on the east side of Frontage Road near the boat launch. The parking lot is open for community use.

For more information, check past Area 6 updates.

Luther Burbank Park: In late November, King County’s contractor moved construction equipment into the back half of the South Parking Lot at Luther Burbank Park. Equipment storage is permitted until May 15. The front half of the parking lot remains open for community use.

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Construction activity in Bellevue*

Area 7. Enatai Beach Park/Lake Washington’s East Channel:

East Channel: Drone surveying to support East Channel substrate monitoring is complete. Crews continue to restore the shoreline in the East Channel. We will provide an update when restoration has been completed.

Enatai Beach Park: Crews continue to work on pipes and structures near the swim beach and under the I-90 bridge. Both parking lots as well as the swim beach, dock, and playground are all open for community use. For more information, check out past Area 7 updates.

Area 8. Sweyolocken/Mercer Slough: The Sweyolocken boat launch and Mercer Slough connector trail is open for community use. Crews are in the area to work on structures near the Sweyolocken Pump Station. For more information, check out past Area 8 updates.

* Construction schedules can change based on factors such as site conditions, weather, and material availability. Please check this website for updates.

Construction status

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This map is updated as construction progresses across north Mercer Island and southwest Bellevue. It shows areas of planned construction, active construction, and post-construction restoration.

If you need this map in another format, please leave a voicemail on the project hotline at 425-305-3578 or call TTY Relay 7-1-1. Reasonable accommodations are available to you for free.

Map current as of February 1, 2025