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Rainier Ave S Landslide Mitigation Project

Updated: December 2, 2020

Rainier Ave S Landslide Mitigation Project is now complete!

We completed construction on the retaining walls and sidewalks in September 2020. After completing landscaping later in the fall, along with a few other punchlist items, the project was closed out in November 2020.  The new retaining walls and sidewalks resolve the long-standing surface slides as well as significant overgrowth obstructing the sidewalk to improve pedestrian safety.

Thank you for your patience and cooperation while we constructed this project. We hope you enjoy these new safety enhancements for people traveling along this stretch of Rainier Ave S. 

Hydro seed placed on exposed soil areas
Hydro seed was added to exposed soil areas
Sidewalk complete at Wall 4

Sidewalk complete at Wall 4

Rockery wall at S Ryan Street repaired

Rockery wall at S Ryan Street was repaired

Rainier Ave S Landslide Mitigation Retaining Wall Map


We're working to address the long-standing surface slides as well as significant overgrowth obstructing the sidewalk along segments of Rainier Ave S from S Carver St to the south City limits near S Ryan St.

Because of limited funds, the project team prioritized the problem areas. In 2016, we installed a 60’ segment of retaining wall and cleared overgrowth from the existing sidewalk to open it up to people walking.

In early 2020, we plan to install the retaining walls outlined within the map below. See our construction mailer for more info. 


SDOT maintains almost 600 retaining walls, most protecting public streets. The average height is 6 feet, and if all the retaining walls and seawalls were lined up end to end, they would extend for 21 miles.


Design: Winter 2016 – Fall 2017
Construction: Installed priority retaining wall and cleared sidewalk in 2016; Remaining retaining wall installation in 2020

Anticipated Construction Impacts

General construction impacts will include noise, dust, vibration, lane restrictions, and potential detours for people walking, biking, and driving.


The project is funded through the City's Landslide Hazard Mitigation Program and managed by SDOT's Street Use division.


Construction mailer (December 2019) 

Project map (2019)

Project map (work completed in 2016)


Greg Spotts, Director
Address: 700 5th Ave, Suite 3800, Seattle, WA, 98104
Mailing Address: PO Box 34996, Seattle, WA, 98124-4996
Phone: (206) 684-7623

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The Seattle Department of Transportation (SDOT) is on a mission to deliver a transportation system that provides safe and affordable access to places and opportunities for everyone as we work to achieve our vision of Seattle as a thriving, equitable community powered by dependable transportation.