Louis Thompson Road Slide Repair


This project constructs a new retaining wall to repair slope damage below Louis Thompson Hill Road at 210th Place SE. A new culvert will be constructed across the road and a roadside bio-retention feature will be constructed between 211th and 210th Place SE.

Project Updates


The city's Contractor plans to work between the following hours during the full road closure on Louis Thompson Road SE:

Road Closure during Work Hours*
7am to 6pm Monday through Friday (November 12 to November 27)
*Lake WA School Buses will be accommodated through the road closure.

After Hours
Single lane signalized traffic control

The Tamarack neighborhood will remain closed at the bottom of 210th PL SE both day and night. Residents of 210th PL SE are recommended to access the neighborhood from 211 PL SE or 210th Avenue NE. There will be detour signs installed for redirecting through traffic (see attached map), and trailer mounted message boards with current information prior to the road closure. See the attached map.

Goals and Benefits

This project will repair slope damage and prevent undermining of the roadway at the existing retaining wall. The stormdrain modifications will help address the flooding and erosion that caused the washouts, and prevent erosion into upper Zackuse Creek.


Construction is planned to begin late September 2018 and finish by December 2018.


$1,275,730 Construction contract. This project is funded in part by the King County Wastewater Treatment Division (WaterWorks grant).

Permits, Environmental Review

Hydraulic Project Approval was obtained from Washington Department of Fish and Wildlife to restore the stream buffer at the base of the wall failure.

  • Road Closure Map: 340 KB Adobe Acrobat Document - Map of the Louis Thompson Road Closure and Detour Route
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