SHALLOW GROUNDWATER FLUCTUATIONS IN UPPER HANGMAN CREEK: FUTURE IMPLICATIONS

Historical land use practices including logging, clearing and grazing activities in the Hangman Creek watershed (Benewah County, Idaho) have impaired hydrologic processes, resulting in degradation of stream habitat and reduced connectivity between the channel and shallow groundwater in the floodplain. Native redband trout populations, wetland communities and riparian vegetation have suffered as a result. Climate change may exacerbate issues of low flow in late summer due to advancement of peak flows as well as increased stream temperature. In response to these issues, the Coeur d’ Alene Tribe has initialized restoration efforts in the watershed including reestablishing native vegetation communities on the valley floor, re-grading and partial excavation of relict channels, removal of drainage tiles/ditches, and placement of large wood debris throughout the stream corridor to aid beavers in dam construction. Sediment delivery, flood hydrology, riparian processes, channel condition, water quality, and biological productivity are being investigated in order to assess and prioritize restoration across Coeur d’ Alene Tribal Reservation lands. The goal of this project is to study how shallow groundwater is affected by seasonal transitions and to assess restoration efforts aimed at reestablishing connectivity to the floodplain. Measurement of water levels in shallow wells over a five year period were used in conjunction with historical data to assess the effects of limited channel restoration and climate change.