Maple Road & Ash Way Intersection and Drainage Improvements

Description - Completed

The Maple Rd and Ash Way intersection reopened on the morning of Wednesday, Oct. 31, 2018. The project was completed in one season with the Interurban Trail and roadway open two weeks earlier than scheduled. The project also finished under budget and without the need for a second season of construction.

Snohomish County and the city of Lynnwood held a public ribbon cutting celebration on Wednesday, Nov. 7 on the project site.

Ash Way Ribbon Cutting Photo
Snohomish County and the city of Lynnwood worked together on the project to help ease flooding in the vicinity of the Maple Rd and Ash Way/Interurban Trail intersection. Flooding events originating from Swamp Creek forced multiple intersection closures per year at this site prior to the completion of the project.

Approximately 700 feet of Maple Rd and 600 feet of Ash Way were reconstructed, along with the Interurban Trail, using structural slabs on top of steel piles. The new intersection was raised roughly five feet from its current elevation and a minimum of six inches above the existing 25-year flood elevation of Swamp Creek. New fish-passable culverts were installed on Maple Rd and Ash Way.


Snohomish County and the city of Lynnwood held an open house for this project on March 15, 2018. Construction began during the spring of 2018, taking one construction season to complete. 

Traffic Impact / Road Closure

The intersection was closed from April 23 to October 31, 2018 for construction. The Interurban Trail was also closed between Beech Rd (behind the Target store) and Alder Way. With consideration of public input, the detour for the Interurban Trail was removed from the project plan. Access to all businesses was available during the project.


The design and construction was fully funded by Snohomish County Public Works Surface Water Management Urban Growth Area revenues and the city of Lynnwood.


Environmental Review - Public Notice

An environmental review of the Maple Rd and Ash Way Improvements was completed in compliance with the State Environmental Policy Act (SEPA). A SEPA Environmental Checklist was issued for this project on July 15, 2016. The drainage system was modified from the original design to reduce impacts to the adjacent wetlands and streams. A SEPA Addendum was issued on March 17, 2017. All SEPA related documents are available by viewing the links below.


Open House (March 2018)

Snohomish County and the city of Lynnwood held an Open House on March 15, 2018 at Lynnwood City Hall in the City Council Chambers. County and city Public Works staff members were on hand to give information about the project and answer questions.


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