Atkinson to Lead SR 530 Emergency Roadway Reconstruction

ARLINGTON, Wash. – Washington State Department (WSDOT) of Transportation has awarded Atkinson a $20 million design-build contract to reconstruct a 1.6 mile portion of SR 530, which was impacted by the catastrophic Oso landslide in March 2014.

 

Atkinson and designer Jacobs Engineering will work with key project partners to design and construct a new roadway in Snohomish County in four months. As part of the project scope, Atkinson will build a significant amount of the new roadway offline — outside the footprint of the existing roadway. This allows the project team to repair, repave, and re-open the existing SR 530 roadway to two-way traffic in just 19 days and suspend the ongoing one-way piloted traffic operations. Due to topographical and flood plain changes from the landslide, the project team will also raise portions of the roadway up to 20 feet to eliminate the chance of future flooding.

 

The project team will tie in the new and old roadways using crushed rock surfacing so that traffic will not drive on gravel borrow until the team installs the final pavement. The team will increase the slope and install horizontal slope drains at the knoll to reduce the amount of excavation by 50 percent. They also will replace six fish passage culverts throughout the new roadway.

 

Finally, instead of paying over $2 million to buy wetland mitigation bank credits, Atkinson purchased a local property adjacent to SR 530 to permit, design, and install a wetland mitigation site. Once complete, Atkinson will donate the property to the Snohomish County Parks Department as a set-aside land trust, which creates open space, species habitat, and room for more wetland mitigation development.

 

Project design and construction is underway and substantial completion is scheduled for late September — a week ahead of WSDOT’s completion milestone.