Confederated Salish and Kootenai Tribes

Stream-Connected Groundwater Basins in Montana: Reconciling Tribal, State and Federal Water Rights Interests

For the Confederated Salish and Kootenai Tribes of the Flathead Indian Reservation, SSP&A has prepared comprehensive groundwater assessments for three major stream-connected groundwater basins.  Present uses within the groundwater basins on the Reservation include irrigated agriculture of non-Indian lands under a federal irrigation project; and, tribal priorities include maintenance of instream flows for fisheries, wetlands and cultural purposes, in addition to water use for economic development. SSP&A has been working for several years to develop and apply groundwater models to assess groundwater management approaches. The groundwater models are among tools being applied in negotiations with the State of Montana and federal entities for a tribal water rights settlement (Compact). 

Avoiding excessive stream depletion or lowering of groundwater levels in sensitive wetland areas are among tribal management targets. SSP&A’s recent work has included the spatial mapping of stream depletion factors at varying points in time, identification of potential groundwater management actions and conjunctive use schemes, evaluation of alternate water use scenarios, and continued update and extension of the models for the Jocko Basin, the Mission Valley and the Little Bitterroot Basin.