Greenhead Slough Barrier Removal Project

State Route 101, Willapa Bay, Washington

Greenhead Slough

This project replaced an undersized culvert that prevented anadromous salmon from accessing the upper reaches of Greenhead Slough and several miles of stream draining to Willapa Bay in southwest Washington State. The work included removal of the culvert, stabilization of several hundred feet of stream bank within the State Route 101 right-of-way, realignment of the stream channel, and construction of a 70-foot-long steel bridge on land owned by the USFWS Willapa National Wildlife Refuge.

Hart Crowser oversaw all aspects of planning, design, permitting, construction, and post-construction monitoring and maintenance activities. We worked closely with refuge managers and WSDOT regional and field staff to ensure compliance with the agency’s 2014 Standard Specifications for Road, Bridge, and Municipal Construction, and to establish and fulfill the terms of the Developers Agreement, bonding, and insurance requirements with WSDOT for the project.