North Mercer Island/Enatai sewer upgrade

General project updates

February 10, 2026

Project-wide updates

King County crews and contractors responded to a sewer overflow near the intersection of North Mercer Way and Fortuna Drive. North Mercer Way and the I-90 Trail at Fortuna Drive are back open to traffic. Public Health – Seattle & King County advises the public to avoid contact with potentially contaminated water in the area until 1:15 a.m. on Sunday, Feb. 15, or until the advisory is lifted. For more information, please see our February project-wide notification.

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 June 27, 2026. For more information, check out our August 2025 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: Crews are conducting investigation work on Southeast 24th Street near the intersection of 81st Avenue Southeast to assess the condition of a pipe and prepare for upcoming repair work. Findings from this investigation work will confirm where repairs are needed. This work is expected to take about three weeks to complete. For more information, please review our January Area 2 notification.

Area 3. North Mercer Way: no updates.

Area 4. I-90 Trail: Crews are continuing pipe repair work on the I-90 Trail. Please follow all detour signs and travel slowly around the work area. For more information, please review our January 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.: Crews are continuing restoration and testing of the odor control unit in the cul-de-sac at the top of 90th Place Southeast. Crews will return to pave a small area behind the odor control unit 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. We will provide an update with more information on final paving and other remaining restoration when the work is scheduled.

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: Starting as early as January 26, small crews of three to five people will conduct environmental survey work in the East Channel and along the nearby shoreline. This work is expected to be completed by January 30, depending on weather conditions. For more information, please review our January 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