Swamp Creek Bridge 503 Replacement


Swamp Creek Bridge 503 is located near milepost .06 on Locust Way between the cities of Bothell and Brier. This bridge is located 400 feet north of the intersection of 228th Street SW and Locust Way. Originally constructed in 1960, the 41 foot span has narrow lanes, no shoulders and no sidewalks. Swamp Creek Bridge 503 does not support the current traffic needs of the area. The existing is bridge is structurally deficient, scour critical, and the vehicle weight limit has been reduced. Funding for a replacement bridge has been secured and construction on a new bridge is proposed for 2024.


The proposed replacement bridge will improve traffic flow for the nearly 10,000 vehicles who access this span of road and provide dedicated spaces for pedestrians and bicyclists. The new bridge would remove in-stream piles and feature a single span design to limit impact on habitats below and provide a more natural flow of water in Swamp Creek.

Traffic Impacts

Residents and businesses near the project site will be notified of any expected traffic impacts when design and construction plans are finalized.

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 July 18, 2021. A SEPA checklist has been completed. The 21-day comment period ended August 9, 2021. 


Federal bridge replacement funds from FHWA and administered by WSDOT Local Programs were awarded in early 2020.