Knapp Creek Passage Barrier Removal

Knapp Creek, tributary to Marsh Creek, is located in the Middle Fork Salmon River watershed. The current irrigation configuration at the Knapp Creek I diversion impedes fish passage and has degraded channel conditions. Project partners will work with Cape Horn Ranch LLC on the restoration of fish passage at the Knapp Creek I diversion. The Knapp Creek Passage Barrier Removal project will remove in-stream impediments, construct a fish-friendly point of diversion, and install a new head-gate. Project actions include completion of final design, and construction of a fish passable diversion that will deliver irrigation into an existing NOAA criteria fish screen. The project will include the installation of a lockable, measurable head-gate and a measuring device. The Custer SWCD has already coordinated efforts with a professional engineering firm to develop a 30% design for the project (PCSRF project 010 23 SA). The project design will be developed to work in unison with the existing IDFG fish screen.

Project benefits include improving passage at all life stages for all fish species and extending connectivity for 14 miles in the stream corridor. The Marsh Creek population supports spring-run Chinook and steelhead, both classified as threatened under the Endangered Species Act (ESA). There are no hatchery-reared salmon released into the Middle Fork Salmon Basin. The Marsh Creek Spring Chinook population is high risk for abundance/productivity and low risk for spatial structure/diversity (NMFS 2017). Low streamflow and entrainment are identified as limiting factors due to the Knapp Creek diversions (NMFS 2017). These actions specifically address at least one limiting factor outlined in Chapter 5 of the recovery plan.