UPDATED: King County Sewer Pipe Replacement Will Disrupt West Lake Sammamish, 2024-2027

An example of open-cut trenching

A trunkline of NW Lake Sammamish sewer pipe has been serving Redmond and Bellevue for 50 years, carrying wastewater to Brightwater Treatment Plant in Woodinville for treatment. King County will soon start working on a project to upgrade 4.5 miles of this sewer pipe to meet the growing needs of the community. King County will build the new pipe in trails, roads, and parks in along West Lake Sammamish Blvd. in Redmond. Completion is expected by 2027. Once complete, the new pipe will provide sewer service for 50 years or more.

Impact to the West Redmond community will be severe during open-cut trenching, though the County is taking every measure to protect the environment. Special attention will be given to tree replacement.

Open-cut trenching will begin at City Hall in 2024.  From there, it will cross the Sammamish River at Leary Way, impinge on Marymoor Park and West Lake Sammamish River apartments and condos, trench around Audubon Elementary and Idylwood Park, with completion at Bellevue's NE 24th Street.  

King County needs to locate a portion of the line on City property on the east side of the Sammamish River within the Sammamish River Trail between Redmond Way and the Redmond Central Connector and has offered to pay the City $10,358.00 for a 2,734 sq. ft. utility easement.  Council must approve.  

Sources:  Council Committee of the Whole, 6/12/2023; RNB post, 12/31, 2019, Opinion /Yoder