Sammamish Plateau Diversion

Project update

September 16 2025

The Sammamish Plateau Diversion Project team is continuing to conduct research as we look at options for new wastewater infrastructure in the east Lake Sammamish area. You may have seen crews earlier this summer as they surveyed the right-of-way (ROW) in the east Lake Sammamish area and just north of the lake in Redmond. This work helps us better understand the area and informs project options.

We anticipate more ROW survey work to happen in the east Lake Sammamish area this fall. As soon as work is scheduled, we will share more information. For the latest details and updates, please visit this project website and subscribe to project updates via text or email.

Visit us at Issaquah Salmon Days Festival

The Sammamish Plateau Project team will be at the Issaquah Salmon Days Festival on October 4 and 5! Stop by the King County Department of Natural Resources and Parks booth, where you can meet and talk with members of the project team. We’ll also be joined by teams from Noxious Weeds, Kokanee Work Group, Coal Creek Sewer Upgrade Project, and Floodplains.

For more details about the event, visit the Salmon Days website: https://www.salmondays.org

We want to hear from you - please take our short survey!

King County’s project team wants to get to know you and your community better. By understanding your needs, we can serve you more effectively during the design and construction phases of this project. Please share your feedback with us by completing this survey. We expect that this survey will take about 10 minutes to complete.

We have two different surveys: one for community members and one for local businesses. If you are both a community member and a local business owner in the project area along East Lake Sammamish Parkway Northeast, please fill out both surveys.

• Community members: publicinput.com/kcwtdsammcomsurvey
• Businesses: publicinput.com/kcwtdsammbussurvey

If you prefer to provide the information in the survey over the phone or by other means, please contact Monica Van der Vieren at 206-477-5502 or monica.vandervieren@kingcounty.gov.

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We welcome you to contact us at any time during the project to talk, ask questions, express concerns, and give feedback and input.