The O’Brian Creek Fish Passage Restoration Project is located on a parcel owned by Seattle City Light and managed for conservation purposes. The project involves replacing an existing 48” diameter culvert, located along the powerline access road, with a 50-foot load-rated steel bridge. The width of O’Brian Creek is 32 feet at this location; therefore the current culvert is undersized at this crossing and causes a debris problem, increased scour downstream, and a velocity barrier for fish passage. The installation of the bridge will eliminate channel constraint caused by the culvert and improve flow conditions and passage of debris.
The goal of this project is to provide complete fish passage for adult and juvenile salmon and trout. Coho salmon and cutthroat trout are the primary species to benefit from this project, but native char (bull trout and dolly varden), stream-type Chinook salmon, steelhead trout, and chum salmon will also benefit. The bridge will provide passage for juvenile salmon to over 100,000 square meters of winter rearing habitat along 2.3 miles of sloughs and wetlands.
This project was identified in a feasibility study which evaluated restoration opportunities in Illabot Creek (Smith and Ramsden 2006), which the O’Brian Creek Complex flows in to. This project was constructed in 2008.
Primary Project Contact
Devin Smith – Senior Restoration Ecologist
Seattle City Light Non-Flow Coordinating Committee
United States Fish and Wildlife Service
Seattle City Light
Smith, D. and K. Ramsden. 2006. Illabot Creek Restoration Habitat Feasibility Study.