SR 530 Emergency Roadway Reconstruction

SR 530 Emergency Roadway Reconstruction address damage from the catastrophic Oso landslide to a 1.6-mile section of SR 530, extending from MP 36.78 to MP 38.24 within Snohomish County. Work included raising the grade of the roadway up to 20 feet to account for the revised floodplain, constructing drainage and stormwater treatment facilities, replacing six fish passage culverts, mitigating wetland impacts, roadside restoration, and erosion control.

Atkinson's approach facilitated the construction of a significant portion of the new roadway in an offline capacity, positioned outside the existing road's footprint. This enabled the repair and reopening of the existing SR 530 roadway in just 19 days, restoring two-way traffic on a paved road. This achievement represented a substantial improvement for residents, particularly when compared to the previous one-way piloted traffic operation on a gravel road. Secondly, during the integration of the new and old roadways, the team committed to applying crushed rock surfacing to ensure that traffic would never traverse gravel borrow areas, effectively reducing the risk of third-party damage. Thirdly, a design innovation was implemented at the project's approximate center, referred to as the "knoll," facilitating a slope increase to 2:1 through the installation of horizontal slope drains. This design adjustment also resulted in a 50 percent reduction in on-site excavation requirements. Lastly, rather than acquiring wetland mitigation bank credits at a cost exceeding $2 million, the team procured a local property adjacent to SR 530, then permitted, designed, and established a wetland mitigation site. Upon completion, Atkinson donated this property to the Snohomish County Parks Department as part of a land trust initiative. This act not only created valuable open space and species habitat but also paved the way for additional wetland mitigation development.

Atkinson completed the project seven days ahead of the scheduled WSDOT completion date and six months after the devastating landslide occurred. Additionally, the local community played an essential role in establishing a memorial, where residents and families came together to plant 43 trees, each symbolizing one of the 43 lives tragically lost in the landslide.