Upper Salmon Basin Groundwater and Surface Water Interactions, P5

The objective of the ongoing Upper Salmon Basin Groundwater-Surface Water (USB GWSW) Interactions project is for the Idaho Department of Water Resources (IDWR) to better define groundwater-surface water interactions in the Upper Salmon Basin, in support of salmon recovery efforts. A more detailed understanding of groundwater-surface water interactions is necessary to evaluate salmonid habitat suitability, as these interactions impact stream stage, flow rate, water temperature, geomorphic conditions, substrate distribution, riparian conditions, and other factors affecting habitat according to the 2019 Upper Salmon Subbasin Habitat Integrated Rehabilitation Assessment (IRA). Currently, most of the data collection and interpretative work is focused on the Lemhi River Subbasin, with the intention of expanding efforts to other basins as needed. Data collected under this project contributes to effectiveness monitoring at a watershed scale, or Intensely Monitored Watershed (IMW) efforts, in the Lemhi Basin. Data collected by IDWR changes according to habitat project needs, and includes streamflow, surface water quality, groundwater levels, and soil moisture data.

This work supports the overarching objective to improve salmonid recovery efforts in the Upper Salmon Basin by measuring and analyzing streamflow and streamwater 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). As such, this project supplies data and information that can be used to evaluate the efficacy of both ongoing and future salmonid habitat restoration efforts. Additionally, as a member of the Upper Salmon Basin Watershed Program (USBWP) Technical Team, IDWR provides technical expertise and advisement on matters concerning the hydrogeology of the Upper Salmon Basin.