Phase 4 detour and trenchless pipe installation coming to Southeast 35th Place as early as April 1

Phase 4 detour and trenchless pipe installation coming to Southeast 35th Place as early as April 1 

Expect traffic detours for homes in neighborhood and traffic control on Frontage Road 

Phase 4 detour begins for neighbors on S.E. 35th Pl. as early as April 1

Crews continue installing pipe west up S.E. 35th Pl. towards East Mercer Way in four phases. Phase 4 is expected to take approximately one month. During this time, S.E. 35th Pl. will be closed between El Dorado Beach Club Drive and East Mercer Way. 

If you live on S.E. 35th Pl., El Dorado Beach Club Drive, or Briarwood Lane, please follow the detours described below:  

• If you live on or east of El Dorado Beach Club Dr., access your home via Frontage Rd. A temporary asphalt access road was constructed to provide local access to S.E. 35th Pl. from Frontage Rd. 
• If you live west of El Dorado Beach Club Dr., continue to access your home from E. Mercer Way and S.E. 35th Pl. A temporary asphalt access road was constructed to provide local access around the work area.  
• There will be no access at and east of El Dorado Beach Club Dr. from E. Mercer Way and S.E. 35th Pl. 
• Flaggers and traffic control signals will direct traffic.  
• There will be a police officer at the entrance to S.E. 35th Pl and E. Mercer Way during permitted work hours. 

During the Phase 4 detour, residents on S.E. 35th Pl., El Dorado Drive, and Briarwood Lane will access their homes via temporary asphalt access roads.

Trenchless pipe installation connecting pipes between 97th Avenue Southeast and S.E. 35th Pl.: 

Crews have been installing pipe using a trenchless jack and bore method on the south end of 97th Ave S.E. This pipe will then be connected to the underground structure that’s in the S.E. 35th Pl. cul-de-sac. 

As early as April 1, crews will begin excavating two large pits: one pit west of the S.E. 35th Pl. cul-de-sac and the other at the south end of 97th Ave S.E off the I-90 Trail. These pits will be used to install pipe under the hillside between S.E. 35th Pl. and 97th Ave S.E. using the trenchless jack and bore method. After excavating the pits, a boring machine will push pipe through the hillside.  

If you live nearby, you may experience increased vibration or noise as crews are excavating the pit areas and drilling underground. Completing this portion of trenchless pipe installation is expected to take approximately one month. 

Upcoming trenchless pipe installation will take place under the hillside between 97th Ave. S.E. and S.E. 35th Pl.

What to expect during construction: 

• Permitted work hours are 7 a.m. to 7 p.m. Monday to Friday and 9 a.m. to 6 p.m. on Saturday. 

• Work outside these hours will be done as approved by the City of Mercer Island. 

• All work will be performed in the public right-of-way. 
• Flaggers, traffic control signals, and single-lane alternating traffic during work hours. 
• Access to the Mercer Island Boat Launch will be maintained. Boat launch visitors should expect flaggers and traffic control signals on Frontage Road.  
• Noise, dust, and vibrations typical of an active construction project. 
• Emergency vehicle access will be maintained. 
• Garbage, recycling, composting, and mail service will be maintained.  

• If services are interrupted, please call the project hotline at 425-305-3587.  

• Construction schedules can change based on factors such as site conditions, weather, and material availability.