Adam RollinsJefferson County, Washington, is working to restore the Duckabush Estuary, conserving the local ecosystem while rebuilding local transportation infrastructure to preserve wildlife habitat and water flow. The project has an estimated cost of $250 million, with construction expected to begin after the design phase concludes in late 2025.
The county estimates that the bridge realignment portion of the project will cost approximately $126 million. This will include replacing the existing causeway with a 1,600-foot-long bridge, raising the road’s profile to survive 100-year flood events and sea-level rise. The county will further improve the bridge’s connectivity by building a turn lane onto the U.S. Route 101 highway and realigning a segment of a nearby road with the bridge.
To prepare for the bridge replacement process, the project will remove the area’s existing causeway and levee. The county will build nearby parking and pedestrian infrastructure for recreation and other amenities—including two parking lots, pedestrian pathways, restrooms, water runoff treatment and a welcome kiosk.
The bridge’s design will play a key role in restoring the local wildlife habitat and channel connectivity. The county will replace three culverts to ensure salmon populations can travel freely. The project also calls for building logjams using removed trees, reconnecting river channels to enhance habitats and installing bioswales to protect water quality.
The county will need to significantly modify the area’s utility systems to support the new bridge and restore the ecosystem. To that end, underground lines will be installed, additional conduits will connect to nearby communities, an overhead line will be placed on the bridge and poles obstructing the estuary will be removed.
Photo courtesy Sam Beebe, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons
