Upper Salmon Basin Hydrologic Monitoring and Analyses III

Idaho Department of Water Resources (IDWR) will continue to support salmonid recovery efforts in the Upper Salmon Basin by providing mission-critical hydrologic data, analyses, and expertise to the Upper Salmon Basin Watershed Program (USBWP) Technical Team (Tech Team) and other stakeholders. The primary purpose of this study is to aid in the development and

evaluation of habitat improvement and water transactions projects. Products will include hydrologic data, data analysis and visualization, hydrologic model outputs, and a final report. All collected data and the final report will be published to public websites. In addition to these products, the project lead, Ryan McCutcheon, will attend planning meetings and provide

technical expertise on the hydrogeology of the Upper Salmon Basin.



Project actions intended to aid the Teach Team include 1) maintaining vital stream gages and measuring surface water flow, 2) collecting groundwater levels, 3) collecting and compiling surface water quality information, 4) analyzing and visualizing the data, and 5) utilizing the Lemhi River Basin Hydrologic Model (LRBM) and Pahsimeroi Basin Hydrologic Model (PBHM) to predict the hydrology and habitat implications of projects, as well as changes to water management, land use, and climate.

This work supports the overarching objective to improve salmonid recovery efforts in the

Upper Salmon Basin by measuring and analyzing streamflow and stream water temperature,

two of the limiting factors to salmon recovery according to the Idaho Governor’s Office of

Species Conservation (OSC) and collaborators (OSC et al., 2019). Salmonid habitat suitability

is also dependent upon stream stage, flow rate, geomorphic conditions, substrate distribution,

and riparian conditions (OSC et al., 2019). As such, data and analyses from this project will

be used to evaluate the efficacy of ongoing and potential future habitat improvement efforts

and water transactions projects. IDWR will also assess the effectiveness of the minimum

streamflow water rights of the 2022 Lemhi River Basin Settlement in mobilizing entrained

streambed sediment from salmonid spawning grounds and increasing overall habitat diversity.

Finally, as a member of the Tech Team, IDWR aims to provide technical expertise and

advisement on matters concerning the hydrogeology of the Upper Salmon Basin.