Bridge 504 carries Locust Way over Swamp Creek. The original bridge was only two lanes and located between Bothell and Brier. Built originally in 1936 and rebuilt in 1958 and 1988, it was replaced in summer 2016.
To meet current federal bridge standards, Snohomish County has replaced the bridge with a new structure that is longer, wider, and several feet higher. The bridge has been lengthened from 41 to 70 feet and widened from 23 to 47 feet. The new bridge has two driving lanes, bike lanes, sidewalks, and railings and guardrails where needed.
The new bridge foundations is outside of the existing creek channel and the center pier has been removed.
Runoff from the new bridge and portions of the road enter a new storm water system and discharge to a bioswale, a type of biofilter designed to remove silt and pollution from surface runoff by directing the water through a drainage course filled with vegetation.
An environmental review of the bridge replacement project was completed in compliance with the State Environmental Policy Act (SEPA). SEPA requires that all state and local agencies identify and evaluate the environmental impacts of their land use decisions. An environmental checklist was prepared July 30, 2012. A Notice of Determination of Nonsignificance (DNS) and Land Disturbing Activity (LDA) Permit have been issued.
These documents are available by viewing the links below or from Snohomish County public works during normal business hours: