The Upper Mainstem Salmon River from the Pahsimeroi River confluence to the headwaters contains Spring/Summer Chinook and Steelhead Salmon returning to the Salmon River basin and Upper Mainstem Salmon. This reach has been identified in NOAA Fisheries Proposed ESA Recovery Plan as having the following limiting factors for listed fish: excess sediment, passage barriers, low summer flows, high water temperatures, lack of instream complexity, degraded floodplain function, and entrainment.  Habitat/recovery needs for these species includes removing passage barriers, increasing flows, increasing habitat complexity, reducing sedimentation, and preventing entrainment in irrigation ditches.  

Three projects are listed for planning and implementation in this contract. One small bridge on Lower Garden Creek, a bridge and reconnect in the Upper Stanley Basin on Cabin Creek, and a riparian exclusion fence in Stanley on Stanley Creek.

Garden Creek (Work Elements L & M)

Garden Creek, a tributary to the Upper Mainstem Salmon River in the 12 Mile reach near Challis, has been an area of restoration focus in past BPA contracts. According to the NOAA Fisheries Spring/Summer Chinook and Steelhead Recovery Plan (2017), tributary drainages with intrinsic potential to support spawning, based on relative habitat suitability under historical unimpaired conditions, include Garden Creek. The confluence of Garden Creek and the Salmon River creates the Hannah Slough, which is an area (with adjacent springs) that has been monitored by Idaho Department of Fish and Game and which has some of the highest densities of Chinook parr in the Upper Salmon.

Key habitat limitations in the Garden Creek watershed include migration barriers/blockages, temperatures, and streambed sedimentation. This project addresses several limiting factors by reducing sedimentation caused by the narrow road culverts and removes a partial passage barriers which addresses improved connectivity.  The Upper Salmon Basin Tech Team, made up of representatives from multiple agencies, ranks projects based on priorities within the Screening and Habitat Improvement Prioritization for the Upper Salmon Subbasin (SHIPUSS). The two bridge projects were ranked for improved access to spawning/incubation and rearing habitat for Steelhead Trout, Bull Trout, Westslope Cuttthroat Trout, and Red-band Trout. The Custer SWCD works with cooperative and willing landowners to implement projects; in small tributaries such as Garden Creek, these types of projects help build trust and relationships with landowners that may result in future projects in the drainage.

For many years the Garden Creek system has not been fully connected to the Salmon River due to at least two complete passage barriers and by low flows.  Consequently, many of the culverts/road crossings were installed to meet the lower flows from Garden Creek, particularly on the mid to lower reaches. Garden Creek irrigation management has improved in the last five years which, by way of water administration, has begun to increase flows in Garden Creek. Improvements coordinated by the Custer SWCD began on Garden Creek with a barrier removal and passage reconnection on lower Garden Creek in 2004 funded by BPA. Several additional years of planning and funding has been invested recently in Garden Creek, resulting in increased flows and removal of three major barriers in Garden Creek. Several road and farm culverts have been impacted by increased flows and extreme high water in the spring of 2017 and again in 2018.  As a result, this double culvert (sized for the lower flows) has been shown to be a partial barrier. Sediment loads due to undersized culvert have also been an impact to the fisheries in the Garden Creek channel. Road improvements above this project have been made by replacing culverts with bridges and remove other barriers. The proposed farm culvert removal will be in cooperation with a project proposed by the Corps of Engineers and Custer County and would include fencing and stream re-habilitation from another funding source.  This will be funded separately from the bridge but will increase and improve the overall project.  

The culvert removal and replacement on Lower Garden Creek not only improves passage in Garden Creek but also protects the Gini Flume that was installed with BPA funds in 2004 and provides irrigation flows flumed over Garden Creek for the entire Round Valley area. This prevented fish from entering irrigation ditches from the mixing of Garden Creek with the Gini Canal. The existing culvert is a double undersized culvert and has washed out twice in the last three years during high water, putting the flume in jeopardy and adding sedimentation to Garden Creek. The design work for this project was initiated in the previous contract (contract #80455) and has been in BPA EC and ETS review during the summer of 2019.

Work completed on Garden Creek since 2004 includes:
• Garden Creek Flume installed in 2004 – Reconnect Garden Creek to the Salmon River by fluming the canal over Garden Creek instead of capturing Garden Creek in the Gini Canal. Contract #1994-017-00
• City of Challis – 3rd Street Bridge – Completed by the City of Challis to address a fish barrier.
• City of Challis Water Conservation project and Diversion improvement (PCSRF and Project #2007-268-00 BPA Contract 49514 - 2015)
• Irrigation Consolidation near City of Challis – Reduced three diversions/passage barriers into one fish passable diversion. (Project #2007-268-00 BPA Contract 59926 - 2015)
• Garden Creek Siphon – Lower Garden Creek: removed a seasonal fish barrier and improved flows. (Project #2007-268-00 BPA Contract 72367 - 2016)
• Garden Creek Chipmunk Bridge installed in 2019
• Garden Creek County Bridge installed in 2019

Upper Salmon Basin (Work Elements J & K)

Upper Salmon projects include a passage barrier removal on Cabin Creek (WE J) and a fence on Stanley Creek (WE K). According to the NOAA Fisheries Spring/Summer Chinook and Steelhead Recovery Plan (2017) the Upper Salmon River Main-stem above Redfish Lake Creek provides a large amount of spring/summer Chinook salmon habitat. The current natural origin abundance remains the highest among populations within the Upper Salmon River MPG and its productivity is among the highest for populations in the MPG. Many conservation projects, similar to the project listed in this SOW, have been completed to address the impacts of human land uses.

Cabin Creek is located in the Upper Salmon River reach above Redfish Lake. Despite its modest size, Cabin Creek is thought to be a key tributary for native fish populations within the Alturas Lake Creek drainage. The complex habitat within its lower reaches near the lake likely served historically as important nursery habitat for salmon and steelhead and foraging habitat for native bull trout. The Cabin Creek culvert replacement project is a collaborative effort with the U.S. Forest Service/Sawtooth National Recreation Area (SNRA). The project will address the removal of an existing barrier and installation of a new structure in the historic channel of Cabin Creek. The current culvert is undersized and in an excavated channel of Cabin Creek. This project would install the new structure, open the historic channel, and
allow for Cabin Creek to access the historic channel. The design work and environmental compliance is being led by the USFS and implementation is planned for 2020. BPA EC and ETS are currently involved in reviewing the designs. The work proposed in this contract is the purchase of the bridge/bottomless arch culvert.

Other work in this contract addresses monitoring previously installed projects (including fencing and irrigation improvement projects) to extend the life of the projects (WE E). There are approximately eight miles of fencing in the Upper Salmon Basin near Stanley that have been installed in previous contracts and may require repair. Most of the fence in need of repair is jack post and pole fence or log worm fence. Within this contract, the District proposes having staff revisit and monitor fencing and irrigation improvement projects installed by the Custer SWCD to assess repair needs and ensure long-term viability of the structures.

Design work (WE I) for additional passage barrier replacement will be done under this contract for implementation in subsequent contracts (in 2020 or 2021). Planning needs by District staff are addressed within this contract to prepare for out-year projects.  Engineering work will be done under this contract to develop plans for two bridges (to be implemented in future contracts):  on Road Creek or Lake Creek. Lake Creek is a tributary to Valley Creek, which provides 68.8 percent of current spawning habitat area, 41.9 percent of miles or current rearing habitat area, and 57 percent of weighted habitat area for the spring/summer Chinook Salmon population (NOAA 2017, Chapter 5). Limiting factors on Valley Creek and the tributaries are passage barriers and degraded riparian and floodplain habitat. These have been identified in planning meetings with the Upper Salmon Watershed office sub-committees, BLM, and technical team members as important fish recovery projects. Planning and engineering will also be done in coordination with NRCS for projects on private land.

References:
NOAA (National Oceanic and Atmospheric Administration) 2017. ESA Recovery Plan for Snake River Spring/Summer Chinook Salmon (Oncorhynchus tshawytscha) & Snake River Basin Steelhead (Oncorhynchus mykiss). NOAA West Coast Region. November 2017. Accessible at: https://www.westcoast.fisheries.noaa.gov/protected_species/salmon_steelhead/recovery_planning_and_implementation/snake_river/snake_river_sp-su_chinook_steelhead.html