The North Fork Willow Creek Culvert Design for aquatic organism passage focuses on the effects of undersized culverts on stream ecosystems and aquatic organism passage, specifically the passage of federally listed endangered Shortnose Sucker (Chasmistes brevirostris). The project documentation reviews the effects of undersized culverts on stream morphology and the migration capabilities of Shortnose Sucker. Additionally, the project documents the design process for developing an aquatic organism-passable structure, with emphasis placed on the Shortnose Sucker, at the road-stream interface of North Fork Willow Creek and Forest Service Road 4017-000. Currently the road-stream interface of North Fork Willow Creek and Forest Service Road 4017-000 is occupied by two squashed six-foot diameter culverts. The long term effects of the undersized culverts have made noticeable changes to the stream ecosystem and may have negatively affected Shortnose Sucker migration.
