This project is an expansion of the existing project 2007-268-000 and was identified early in the BPA State of Idaho MOA process as a high priority for inclusion.  Both the IDF&G and the draft NOAAF recovery plans highlight the importance of carrying out habitat actions to assist this key salmon population.

The Pahsimeroi River has a unique population of Snake River Chinook salmon, and in contrast with the Lemhi River and East Fork of the Salmon River watersheds, the salmon population in the Pahsimeroi River is a later migrating summer-run Chinook salmon rather than spring-run. Historically, spawning and rearing habitat was probably supported within the watershed for at least two federally –listed anadromous fish species, spring/summer Chinook salmon, and steelhead. (P. Murphy, 2008)  

The Upper Salmon Watershed Project Technical Team, including IDFG Anadromous Fish Screen Program and Regional Fishery Management has prioritized the lower Pahsimeroi River and its major tributary, Patterson/Big Springs Creek, as SHIPUSS Priority I streams. Those are tributaries and river reaches that have the potential to realize immediate, tangible benefits to fish if recovery efforts are directed toward them. Goals in the lower Pahsimeroi River and Patterson/Big Springs Creek are to enhance migration in both streams by increasing flow regimes and reestablishing habitat connectivity to unused stream reaches. Mechanisms for attaining these goals focus on diversion consolidations and removal/alterations of diversions hindering fish passage. (P. Murphy, 2008)  

At the request of the Idaho Governor’s Office of Species Conservation (OSC) a technical panel with knowledge and expertise of project opportunities within the Pahsimeroi. This team included Paddy Murphy (Fisheries Biologist), Eric Leitzinger, Larry Weeks, Lynn Stratton and Jim Lukins, Idaho Department of Fish and Game, Morgan Case and Helen Herrington, Idaho Department of Water Resources, Mark Olson, Natural Resources Conservation Service, Brian Hamilton, Bureau of Reclamation, Mark Davidson, TNC, Clif Tipton, Bureau of Land Management Fisheries Biologist, Mike Edmondson, OSC and Karma Bragg, Custer Soil and Water Conservation Service. This core team identified the areas of Pahsimeroi with most potential for fisheries enhancement and recovery within the middle Pahsimeroi. Additional support and input is provided by the Custer Soil and Water Conservation District Board of Supervisors. The projects were predominantly in the mid to upper Pahsimeroi. Patterson/Big Springs Creek is a very important tributary for spawning and rearing of the unique population of Chinook salmon found in the Pahsimeroi. Continued opportunities to improve and enhance this area will be addressed in the project planning.

P-13 is an un-screen diversion in the Pahsimeroi that is currently a fish barrier. By working with the two landowners within this system to find alternative irrigation water source this barrier could be removed and several other tributaries reconnected including Sulphur Creek. The next diversion upstream from P1-3 that will need to be addressed is P-14 screening (IDFG) P-16 and P-17. By modifying existing irrigation practices, providing pipe to transport the flows for irrigation and potentially using a well or wells the passage barriers could be improved and flows increased from 10 to 15 cfs in the mid to upper Pahsimeroi. At present landowner interest in these opportunities is high.