Hunter Point Road Culvert Replacement Thurston County, Washington
After 100 years away, Salmon returned to the Hunter Point Road culvert following its rehabilitation along with the stream it facilitates. Thanks to the investment by Thurston County, Washington, including state grants, a deep ravine and large drop downstream of the Hunter Point Road Culvert to remove a barrier to fish passage.
A Complicated Stream Restoration Design for a Top-Priority Culvert Replacement Project
Thurston County received state grants for culvert replacements, and Hunter Point Road was their highest-priority fish passage project. The project involved a new bridge and complete stream reconstruction. Complications included high road embankments, a single access road (dead end), a stream confluence immediately upstream of the crossing, and the need to provide habitat function to the stream beneath the bridge structure. After consulting with the tribes and the Washington Department of Fish and Wildlife, the team elected to include large woody debris in a variety of configurations along with specific stream bed geometries and materials. During construction, the County fish salvage team relocated approximately 500 fish from the downstream reach, indicating the high potential of future use upstream of the project. Otak structural engineers designed an 80-foot-span bridge to replace the existing four-foot-diameter culvert. Shortly after construction was complete, spawning salmon returned, after almost a century-long absence. The project represents a historic moment, and a tribute to the funding agencies and Thurston County for funding this project and hiring Otak to bring it to fruition.