North Mercer Island/Enatai sewer upgrade

General project updates

December 2, 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 December 27, 2025. For more information, check out our August 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: Crews continue work to upgrade the pump station, including work on the pump station building, the generator building and testing newly installed systems.

Area 2. North-central Mercer residential streets: King County's contractor completed pipe repair work on Southeast 24th Street between 78th Avenue Southeast and 80th Avenue Southeast. Temporary paving is expected to be completed by the end of November.

Crews completed temporary paving on 81st Avenue Southeast. They will return in the spring to complete the final paving of both areas once the permitted paving window reopens. We will notify the community when the final paving has been scheduled.

Area 3. North Mercer Way: no updates.

Area 4. North Mercer Way: As early as December 3, crews plan to pave the pullout shoulder on N Mercer Way, just west of Fortuna Drive. This work is expected to be completed in one day. During paving, flaggers will direct single-lane alternating traffic, and pedestrian and bicycle access will be maintained. This work is weather-dependent and may be rescheduled. Crews will return for final paving during the next permitted paving window, which begins in Mid-March.

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.: As early as December 3, crews plan to pave a pave a small area behind the odor control unit in the cul-de-sac at the top of 90th Place Southeast. This work is weather-dependent and may be rescheduled. Crews will return for final paving during the next permitted paving window, which begins in Mid-March. For more information, check past Area 5 updates.

Area 6. NE Mercer Island: 

Fruitland Landing: Restoration work is continuing inside the park at Fruitland Landing. Work outside the park, including removing the temporary bypass piping and access ramps along 97th Avenue Southeast, and backfilling and temporarily paving the intersection of 97th Ave SE and Southeast 34th Street, has been postponed. We will provide an update when this work has been rescheduled. For more information, please review our recent Area 6 notification.

S.E. 35th Pl: Crews completed grinding and temporary paving on Southeast 35th Place and Frontage Road. Restoration work in this area continues.

For more information, check past Area 6 updates.

Luther Burbank Park: King County’s contractor has moved construction equipment out of the back half of the South Parking Lot at Luther Burbank Park. The full parking lot is open for community use. 

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Construction activity in Bellevue*

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

Enatai Beach Park: By early December, crews will complete restoration of the work area under the bridge at Enatai Beach Park and reopen that area to the public. Two smaller areas in the southern part of the park will remain closed until the remaining in water pipe work is completed next year. For more information, please review our November Area 7 notification.

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