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Lake Hills and NW Lake Sammamish sewer upgrade
The Lake Hills and NW Lake Sammamish Sewer Upgrade Project will upgrade 4.5 miles of sewer pipes serving the growing Redmond and Bellevue area.
Project description
The Lake Hills and 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 is 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 Redmond.
Construction on the project is expected to begin in 2027 and may impact your daily routine. When the project is complete, the new pipe will provide sewer service for 50 years or more.
Project update
September 2025
That’s a wrap on summer!
Thank you to all who visited our project booths this summer! Our team engaged with over 300 community members this summer during events like Bike Everywhere Day, a National Night Out neighborhood block party, and the BECU GoGreen Movies at Marymoor Park.
This summer, our project team also connected with neighbors located directly along the project alignment to share an updated project factsheet. Our team will continue updating property owners and project neighbors throughout final design.
To find more detailed information about our summer events, view the event summaries on our public engagement page.
What’s next?
Final design will continue through this year. We are currently scheduled for a pre-permitting Hearing Examiner public meeting on September 15. If our application with the City of Redmond is approved during that meeting, our team can finalize design and begin permit applications. We will share a more detailed project schedule when we are closer to hiring a contractor.
Designing large sewer upgrades take time… Construction now expected to begin in 2027
King County continues to update the design of the sewer upgrade project to meet permitting requirements from the City of Redmond, the City of Bellevue, and several state and federal agencies. Coordination with our partner agencies is necessary to make sure we install the new pipe in the safest way possible, limit impacts and maximize improvements for people and the environment.
Due to a delay in the design and permitting processes, we anticipate construction will begin in 2027. Thank you for your patience while we work hard to finalize our sewer design.
Interested in a project briefing for your community group?
We are happy to meet with you or come to your next community event to share the latest project information and to answer questions you might have as we get closer to construction. Please contact Annie Plumley at 206-263-3203 or aplumley@kingcounty.gov for more information.
Sign up for project text alerts
Be sure to sign up for project updates to stay up-to-date on the latest project information and upcoming events. You can also get updates from your phone. To sign up for text alerts, text KING REDMONDSEWER to 468-311.
Previous project updates
- Designing large sewer upgrades take time... Construction now expected to begin in 2026, July 1, 2024
- Project update, August 23, 2023
- Survey work along 177th Ave NE starting as early as May 8, May 2023
- Construction expected to begin in 2024, Spring 2022
- Fieldwork along sewer alignment scheduled to begin the week of March 21, March 21, 2022
- Delays and increased congestion on and near West Lake Sammamish Parkway beginning as early as November 1, October 28, 2021
- Summer 2021 Project Newsletter, August 2021
- Expect delays and increased congestion on and near West Lake Sammamish Parkway beginning as early as August 31, August 28
- Summer 2020 Project Newsletter, August 2020
- Expect delays and increased congestion on and near West Lake Sammamish Parkway starting as early as July 13, July 8, 2020
- Fall 2019 Project Newsletter, October 2019
- Join us at Bike Everywhere Day on May 17! May 10, 2019
- Catch up on our design process and read about what's next!, August 2018
- Join us at Bike Everywhere Day on May 18! May 11, 2018
- Expect short delays on West Lake Sammamish Parkway and residential streets beginning March 20, March 14, 2018
- Online Open House archive (December 2017 - January 2018), February 6, 2018
- Stop by the online open house to review and comment on the latest project designs! December 5, 2017
- Final design for the Lake Hills and NW Lake Sammamish Sewer Upgrade Project begins, November 2017
- Join us for drop-in sessions in November! November 1, 2017
- Expect increased noise and activity in Luke McRedmond Landing starting as early as Oct. 16, October 9, 2017
- Soil sampling in ravine scheduled to begin as early as September 7, August 31, 2017
- Soil sampling on 180th Ave. N.E. continues September 6, August 29, 2017
- Contractor moving to Sammamish River Trail this week. Sampling on West Lake Sammamish Parkway complete, August 15, 2017
- Soil samples begin on 180th Avenue August 14, August 9, 2017
- Soil samples continue August 7 on West Lake Sammamish Parkway, August 2, 2017
- Expect lane and sidewalk closures, short delays on West Lake Sammamish Parkway and local roadways starting as early as July 31, July 27, 2017
- Soil samples starting July 31 on West Lake Sammamish Parkway and 177th Ave NE, July 27, 2017
- Sammamish River in-water survey work north of the Leary Way Bridge week of July 5, June 28, 2017
- Expect short roadway and trail delays during utility investigations starting as early as Monday, April 24, April 18, 2017
- Fieldwork efforts nearing completion – alignment for new sewer pipe to be finalized in early 2017, November 29, 2016
- Geotechnical work this week, WTD's GoGreen booth a hit, and Pokemon, don't Go here! July 25, 2016
- Geotechnical work begins June 23 in Idylwood for King County’s sewer upgrade project in Redmond, June 22, 2016
- Project update, June 8, 2016
- Project update, February 2016
- Project news, January 2016
- King County touring your area, April 24, 2015