Little Springs Creek Restoration

Project Narrative

This project reconstructed the lower 0.35 miles of channelized Little Springs Creek to create low gradient and sinuous salmonid spawning and rearing habitat. Instream habitat complexity was enhanced by installing instream structures. A total of 20 structures were installed in the channel: Eighteen logjams were installed and each will result in a future pool created by channel scour and two rootwads were installed one at the lower end of the worksite and one at the upper end of the worksite. The revegetated area at this worksite was 20 feet wide on each side of the newly constructed 0.35 mi. channel encompassing a total area of 1.7 acres. 250 live willow clumps (Salix spp.) that were transplanted into the riparian area which were also hydroseeded and mulched with a certified weed-free native seed mix. There was no invasive plant control done at this site. The new floodplain was constructed at elevations to allow natural inundation of flow and sediment into the riparian area. An existing fence was taken down during construction and reconstructed after construction approximately 50 from the restored stream channel. A 0.06 mile side channel to the Lemhi River was created to provide salmon and steelhead spawning and rearing habitat. A total of 16 structures were installed including the following: two rootwads, 4 rock and log structures and ten log barbs which will result in pools created by channel scour. A total of 1,000 feet of wetland sod mats were installed around the side channel (in some areas in more than one mat deep) and 250 live willow clumps (Salix spp.) were planted at the project worksite; the project area was hydroseeded with a native seed weed-free mix upon completion of the project. This riparian treatment covered a 20 foot buffer along each side of the side channel along the 0.06 length of stream which encompasses 0.29 acres. The new floodplain was constructed with elevations that would allow for natural inundation of flow and sediment into the riparian area. A new jack fence was constructed along 0.11 miles of the new side channel. An additional meander length of approximately 0.42 miles of fence along both sides of river was installed immediately downstream of the constructed side channel to protect the Lemhi River from livestock grazing; this was a variation from the originally proposed work. The additional fencing increased the riparian protection area by 1.5 acres for a total worksite riparian area treated of 1.79 acres.Repair to worksite #2 was done after substantial ice-scour the winter following the construction. The repair included adding topsoil to stabilize and raise the elevation of the riverbank and installation of two more rootwads.The total meander length of the stream treated in this project was 0.48 miles and the total length of fencing installed was 0.94 miles.