Making way for fish

A fish passage barrier is anything that hinders fish from moving downstream or upstream for reproduction, growth, and development.

An old culvert on Sapp Road, installed nearly a century ago, impeded fish migration because the water flow was too swift. The City of Tumwater began construction of a new culvert using stream simulation methodology in the summer of 2026 as part of the Percival Creek Fish Passage Barrier Removal Project.

Removing the Sapp Road fish barrier will improve fish access for miles.

The Percival Creek Fish Passage Barrier Removal project on Sapp Road involves removing an undersized, 5-foot diameter culvert and replacing it with a 19-foot wide box culvert that will allow fish to more freely navigate Percival Creek.

Percival Creek was rerouted around the worksite and thousands of fish and other aquatic life were safely relocated downstream prior to construction.

Environmental protection measures safeguard the surrounding creek and natural resources throughout construction.

The inside of the new culvert is being filled with material that mimics the existing streambed.

Removing barriers

Removing and replacing the undersized culvert under Sapp Road will restore access to approximately 7,300 feet of mainstream habitat, 9,052 square feet of spawning habitat, and 882,750 square feet of fish rearing habitat in cool water for Chinook, chum, coho, steelhead, sea-run cutthroat, and resident trout.

City of Tumwater engineers worked with the Washington Department of Fish and Wildlife, local tribes, and environmental consultants while designing the project.

Future restoration projects

Tumwater is currently in the design phase of another key restoration project on Percival Creek. The city plans to remove the undersized culvert that conveys Percival Creek under Somerset Hill Drive and replace it with a full bridge span. This upgrade will eliminate a partial fish barrier, restore unimpeded passage for salmon and wildlife, and give the creek room to meander naturally. By allowing sediment movement and channel migration, the project will strengthen habitat and improve overall ecological function. 

As more fish barriers are removed, Percival Creek is positioned to become increasingly important salmon habitat for future generations. The Somerset Hill Culvert Replacement project is slated for construction in a few years when funding becomes available.

Learn more about fish passage on the Washington Department of Fish & Wildlife webpage.