Alderwood Mall Parkway Corridor Improvements


Snohomish County Public Works is proposes to widen Alderwood Mall Parkway from the 16800 block to the SR 525 ramps. The project would widen the road to five lanes, including a center turn lane, add new shoulders, bike lanes, sidewalks, gutters, curbs, drainage facilities and new traffic signals at the SR 525 ramps intersection. 


  • 2019-2020: Completed field survey, preliminary design and environmental studies
  • 2021-2023: Design, environmental review, right of way acquisitions and utility relocations
  • 2024: Construction to begin

Traffic Impact

Single lane closures will be utilized during construction and business access will be available during the project.


The project cost is estimated at $13 million and will be funded by the Snohomish County Road Fund, Mitigation Funds, and Surface Transportation Program (STP) Funds. In addition, this project has received $2.58 million in grant funding from the Federal Highway Administration.

Environmental Review

A SEPA determination will be made later in 2022.

Land Disturbing Activity (LDA) Permit

This project will be reviewed for compliance with Chapter 30.63A (Drainage) and Chapter 30.63B (Land Disturbing Activity) SCC, as well as other applicable regulations in Title 30 SCC. Public Works will exercise its authority under Rule 5001 (Revised 10/2020).

A notice of Land Disturbing Activity (LDA) was published on June 27, 2021. A SEPA checklist has been completed. The 21-day comment period ended July 19, 2021. 


SEPA Checklist - June 2021
LDA Postcard - June 2021
Design Report - June 2021
Postcard - November 2019