North Fork Salmon River Habitat Restoration Design Dingey Property

The North Fork Salmon River Habitat Restoration Design Dingey Property project developed a 30% design and cost estimate for instream habitat restoration on the mouth of Sheep Creek and 0.3 mile (12 acres) of the North Fork Salmon River. The collection of background data resulted in an optimal restoration project design for this reach. Design elements include connecting the floodplain throughout this reach, as well as creating lateral habitat where feasible. Implementation of this design will improve spawning, holding, summer rearing, and overwintering habitat for ESA listed Snake River Sp/Su Chinook Salmon and steelhead. A PCSRF award was applied for and awarded for the construction phase of this project, which will take place in 2021.

Engineering services completed include: topographic and bathymetric surveys, site visits to determine project components and construction access, development of CAD surface and layout of existing conditions and conceptual design, 2D hydraulic model of existing conditions, analysis and hydraulic data: stream stats and IDWR gauge, 2D hydraulic model of preliminary proposed conditions, historical photos, and reference reach info. This data was used to produce a CAD layout of preliminary design plans, a draft design memo, and the development of a cost estimate for final design and construction.

Currently, there is very little habitat complexity in this reach of the North Fork Salmon River. The channel is fairly straight with a uniform width and depth. The substrate is mostly large cobbles and boulders that don’t provide much holding cover. There is very little woody debris in the river throughout this reach. This area currently lacks staging areas, overwintering habitat, habitat complexity, and spawning gravels. This reach has a disconnected floodplain, likely due to human made dikes and developments. There currently is no development in the elevated floodplain and the landowners would like to see it functioning properly to benefit fish and wildlife.

This project will produce engineering designs to improve spawning, holding, summer rearing, and overwintering habitat for ESA listed Snake River Spring/Summer Chinook salmon and steelhead. This project will also benefit bull trout, westslope cutthroat trout, rainbow trout, and mountain whitefish.