Sweetwater Creek Ecosystem Restoration

Three stretches identified in the Sweetwater Creek Ecosystem Restoration Feasibility Study of Sweetwater Creek (SW-01, SW-05, and SW-07) located in 1.5 miles of designated critical habitat and affecting 36.5 acres of riparian habitat have been selected for restoration under the joint partnership project between the Nez Perce Tribe and the United States Army Corps of Engineers. First year project outcomes are designs (up to 60%) of these reaches, which focuses on increased quality and quantity of instream habitat, improved stream process of flood conveyance, floodplain and side channel engagement, and sediment transport through new stream designs and restoration. The PCSRF funds will provide funding towards the Nez Perce Tribes portion of overall project implementation costs. This funding will work in concert with other funding sources to satisfy the Tribes share of this project. Designs will be completed by October 2026 and implementation completed by approximately summer of 2028.



This project addresses four of the six limiting factors for the Lapwai Creek Watershed (habitat diversity, sedimentation, temperature, and passage) which were identified in the Lapwai Creek Ecological Restoration Strategy (LCERS). This project falls within Sweetwater Creek Reach 1. Sweetwater Creek Reach 1 was the second highest ranking assessment unit in 2009 when the LCERS was developed even though surface diversions reduced streamflow by almost 100%. Currently, the Tribe is involved in the Lewiston Orchards Project Water Exchange and Title Transfer Project (LOP) which is reducing the surface diversions to increase streamflow to the Sweetwater Creek watershed. Prior to 2006 summer base flows were reduced to 0.0 cfs. The 2020 Biological Assessment proposes base flows with up to 12.5 cfs. These increased stream flows along with the with this proposed project will restore, provide access to, and increase the amount designated critical habitat within Sweetwater Creek. Future funding for the remaining phasing consisting of design and implementation will include Bonneville Power Administration and Nez Perce Tribe Snake River Basin Adjudication funding.



Worksite #:1 PCSRF funds will provide for restoration implementation on approximately 2,500 feet of stream channel, 8.75 Acres of riparian area. This worksite is located at the bottom reach of Sweetwater Creek upstream of where it meets Lapwai Creek between the U.S. Highway 95 bridge and the property boundary upstream near RM 0.45. The PCSRF funds will be used in the implementation for the following restoration actions and benefits, to help restore the reach to a natural condition: (Riparian Restoration, Channel Improvement, Instream Structure, Floodplain Construction and Grading Transitions, Streambank Shaping, and Levee/Berm Notching).



Worksite #2: PCSRF funds will provide for restoration implementation on approximately 2,700 feet, 14 Acres of riparian area. This worksite is located downstream of the Webb Road bridge crossing and upstream of the Webb Rose Lane bridge. More specifically, it extends approximately 2,300 feet between RM 2.02 and 2.46. The PCSRF funds will be used in the implementation for the following restoration actions and benefits working towards restoring the reach to a natural condition (Riparian Restoration, Channel Improvement, Channel Realignment, Instream Structure Installation, Floodplain Construction and Improvement, and Streambank Shaping).



Worksite #3: PCSRF funds will provide for restoration implementation on approximately 2,500 feet, 13.7 Acres of riparian area. This worksite is located above the McCormack Ridge Road bridge, running upstream for approximately one-half mile. The PCSRF funds will be used in the implementation for the following restoration actions that will restore the reach to a natural condition: (Riparian Restoration, Channel Improvement, Channel Realignment, Instream Structure Installation, Floodpl

Expected benefits to target Salmon species include restoration of approximately 1.5 miles of Lower Sweetwater Creek and approximately 36.5 acres of riparian area adjacent to Sweetwater Creek. This project will improve quantity and quality of designated critical habitat for ESA-listed Steelhead and Fall Chinook, and reintroduced Spring Chinook and Coho Salmon.