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Pacific Highway Emergency Culvert Replacement
Submitting Company: Otak Inc.

Location: Clark County, Washington
Cost: $493,790
Start Date: February 2019
Completion Date: March 2019
Owner/Developer: Clark County Public Works
Engineer: Otak Inc.
General Contractor: Thompson Bros. Excavating
Subcontractors: AA Asphalting, All County Concrete Cutting, Cadman, Core & Main, CSI Construction Services, Dirt & Aggregate Interchange, Ecological Land Services, Geotk, JL Storedahl, Pacific NW Locating, Summerhill Trucking, Sunmark Seeds International, West Coast Sand and Gravel

Heavy snow and rain in February 2019 caused the existing culvert under Pacific Highway, northwest of La Center, Washington, to become obstructed by debris and impounded water on the upstream end. Clark County immediately closed the road, which was severely undermined by a 20-foot-wide by 17-foot-deep scour hole underneath. The reinforced concrete panels of the old highway remained suspended until failing a couple of mornings later.

The project goals were to maintain public safety and quickly reopen the roadway to the public. During the closure, local residents were detoured 7-10 miles from standard routes, emergency service times were longer and services had to be shifted to alternate fire stations for support. The route serves as an alternate for truck traffic bypassing the load-limited I-5 Woodland East Fork Bridge.

The team also wanted to avoid a typical approach of installing a temporary culvert that would need to be replaced later. In addition, they needed to restore fish passage in a cost-effective way that avoided utility shutdowns.

The design team and contractor worked together to construct a 13-foot span culvert embedded with a natural stream bottom to repair the road and provide new fish passage. The road reopened 45 days later.