Pole Creek Passage and Restoration

Project Narrative

An irrigation diversion located on U.S. Forest Service land in the Sawtooth National Recreational Area (SNRA) is used by a landowner. The use of the old diversion significantly reduced flow in Pole Creek for adult Chinook to spawn and the irrigation diversion was a barrier for juvenile fish. Federal, state, and conservation agencies, Tribes and the landowner worked together to address the flow and passage issues in Pole Creek. IDFG removed an existing irrigation diversion that was a fish passage barrier to spawning and rearing habitat for Chinook and juvenile fish. Removing the barrier resulted in an additional 7 miles of access upstream. As part of the new irrigation system a new fish friendly head-gate (diversion) was installed by IDFG, including installation of a NOAA Criteria screen replacing an old fish screen resulting in approximately 10,860 acre feet of water screened per year. Two new water wells were drilled and water rights were secured for both wells. Approximately 12.5 miles will be protected for adequate flow (4.5 miles of Pole Creek and 8 miles of the Salmon River). A buried electrical power line was installed which replaced the Pole Creek hydro-power system. Approximately five miles of pipeline was installed for the wells and the irrigation system. Two pumps and two pump houses were installed. The old pivot sprinklers were replaced with 10 new more efficient pivot sprinklers and the pivot no longer crosses Pole Creek. Although not originally proposed a new gauge was installed at the old diversion site to monitor flow in Pole Creek. The water provided by the new wells and the surface water gained through the irrigation improvement allows 18 cfs of flow to remain in the stream. The 18 cfs was established as the benchmark necessary for functioning habitat for ESA listed fish in Pole Creek. A total of 2803 acre feet of water will be conserved per year as a result of the irrigation improvement which began on 12/31/15 and will be in effect until 12/31/2030. The landowner was a major contributor in completing the project, including painting the pivot sprinklers to comply with the SNRA requirements for scenic values in the area. The Pole Creek project involved many other partners who completed projects that complemented this project: The SNRA removed a culvert and installed a bridge on Pole Creek prior to this project. The Shoshone/Bannock Tribes removed a fish passage barrier culvert and replaced it with a bridge. At the same time they installed a pipe sleeve under the stream which eliminated the need for the new pivots to cross Pole Creek when the irrigation improvement was completed. They also fenced off the entire reach of Pole Creek private property with permanent fence effectively closing water gaps. These actions were completed before, during and after this project. The Fish and Wildlife Service and the Natural Resources Conservation Service provided funds and NRCS and Custer Soil and Water Conservation District installed stock water tanks in the upland area to provide water for livestock that could no longer access the stream after the water gaps were closed by the fence installed by the Tribes. Sufficient flows a maximum of 18 cfs, will be maintained in Pole Creek from June 1 until the natural upsteam flows are above 23 cfs When natural stream flows are above 23 cfs, a maximum of 5 cfs can be withdrawn so long as downstream flows remain above 12 cfs. If downstream flows drop below 15 cfs during an irrigation season, a minimum of 15 cfs will be maintained season long the following year. Maintaining sufficient flows in Pole Creek will to allow for fish passage, spawning, and incubation rearing for salmon and steelhead. Fish will also have access to more habitat through the removal of barriers and maintained flow.