Big Bear Creek Trap and Haul

Big Bear Falls are a set of waterfalls that impede wild steelhead Oncorhynchus mykiss access to high-quality spawning and rearing habitat in Big Bear Creek (BBC) in the Potlatch River basin. Life cycle modeling exercises indicate enhanced fish passage at Big Bear Falls could significantly improve smolt production in the watershed. Previous plans to modify the falls to enhance steelhead passage were terminated due to permitting concerns and an alternative approach is needed to maximize the production potential of upstream habitat. The Idaho Department of Fish and Game (IDFG) will trap and haul adult steelhead upstream of Big Bear Falls for three consecutive years (2023-2025). Project activities include operating a fish weir at the mouth of BBC to trap pre-spawn adult steelhead and transporting these fish above the falls to facilitate migration and dispersal upstream. The project will provide steelhead access to approximately 12 miles of high-quality spawning and rearing habitat directly upstream of the falls, as well as 40 miles of stream habitat in the headwaters of BBC. There are no known fish passage barriers in the 12 miles of quality habitat directly upstream of the falls.

The goal of the Big Bear Creek Trap and Haul project is to provide steelhead access to additional spawning and rearing habitat in Big Bear Creek (BBC), the largest drainage in the Big Bear subwatershed. Rearing capacity within the Big Bear subwatershed is limited, resulting in strong density effects on emigrants-per-female productivity. Big Bear Falls impede wild steelhead access to over 50 miles of potential spawning and rearing habitat in BBC. Life cycle modelling exercises indicate enhanced adult steelhead passage at the falls could increase smolt production in the subwatershed by an additional 5,000 smolts (Uthe et al. 2017). Transporting adult steelhead around Big Bear Falls will directly increase available habitat capacity in the drainage and potentially alleviate density-dependent effects and increase population productivity. Information gained from this project and future studies will allow IDFG to assess the production potential of habitat upstream of Big Bear Falls and determine if trap and haul is a viable, long-term management solution to passage issues in BBC.