Sweetwater Creek Reach 3 Floodplain Restoration

The majority of the objectives were met during implementation of this restoration project. All of the off channel habitat areas were constructed according to design and the entire lower section of new channel was constructed with all large wood habitat structures as well as all pool/riffle and pool/run/riffle sequences. All of the habitat structures were built and implemented in the existing channel according to design as well. All of the debris and garbage material was collected and hauled off site. All of the targeted undesirable vegetation was removed and the entire disturbed area was seeded with a native riparian grass and forb mix.

There were some variations between the proposed project and the final project implemented. The most upstream section of new channel construction did not occur due to a change in field conditions from the time the design work was done and project implementation. According to design approximately 350 feet of new channel construction was to take place in the most upstream extent of the project area utilizing a historic side channel as the new primary creek channel. After data was collected for the design, this portion of Sweetwater Creek experienced significant incision, making it impossible to divert and re-enter the creek at this location. It simply wasn’t possible to construct a channel diversion structure of the size necessary to create that much head and stay within project budget. That is the reason the project created 0.30 miles of new stream channel versus the planned 0.36 miles of new channel. This is also the reason that the 13 large wood structures proposed was reduced to 11; the other two were to be placed in that uppermost extent of the project area that was not feasible to construct.

This project will benefit Snake River steelhead. The project will increase juvenile rearing habitat and improve riparian function due to streambank stability, large woody debris recruitment and floodplain connectivity.