East Fork Potlatch Bridge above Mallory Creek

The Clearwater Soil and Water Conservation District (Clearwater SWCD), in partnership with PotlatchDeltic, proposes to replace an undersized culvert that is a partial fish barrier on the mainstem of the East Fork of the Potlatch River above Mallory Creek. A new bridge at this site, sized appropriately for high flows and passage of all aquatic organisms, will fully open up the last 4.2 miles of habitat on the mainstem and another potential five miles of habitat in tributary streams. This culvert, on the main access to the area, East Fork Road 512, is the only crossing on the mainstem of the East Fork Potlatch River which is not a bridge. The current culvert is undersized and poses a failure risk, which could deposit many tons of sediment into the East Fork and affect habitat for steelhead and other aquatic organisms.

This project would eliminate a partial migration barrier in the East Fork of the Potlatch, allowing unimpeded fish movements in the high-quality habitat of the upper East Fork of the Potlatch. In addition, the project would minimize the risk of stream crossing failure and delivery of many tons of sediment to the East Fork. A bridge will more naturally mimic stream hydrologic and hydraulic processes than the undersized culvert. The new bridge will offer resiliency to the effects of climate change by passing higher flood flows.