Western Native Trout Initiative

Proposed Accomplishment Summary
Replace existing stream crossing with properly sized stream simulated crossing to provide unobstructed passage for resident coastal cutthroat trout, and other native species, through the crossing. Provide unobstructed access to 8 miles of trout habitat.

The importance to the Resource
The culvert is managed by BLM. The BLM also is concerned about coastal cutthroat trout because it is considered a species at risk of becoming threatened or endangered in the future. Expanding cutthroat trout access to habitat in Coleman Creek, upper South Fork Alsea River, would strengthen productivity and genetic diversity of this species.

The problem
Coleman Creek culvert is undersized for the watershed area upstream of the pipe resulting in excessive scour downstream of the culvert. The culvert is nearing the end of typical lifespan for culverts of this type, multiple signs of wear and rust. These two limitations indicate this pipe is in need of replacement.

The method
Replace existing culvert with properly sized culvert to pass 100 year events. Oversize pipe according to ODOT stream simulation criteria, 1.2 times bankfull plus 2 feet, and to located at bed elevation and gradient to maintain natural substrate thru culvert.