Ground Water Investigation Program

In Montana, groundwater is essential for safe drinking water supplies and for economic growth. On average, approximately 272,000,000 gallons (835 acre feet) are extracted from Montana’s aquifers every day. In many areas of the State, groundwater is the only reliable year-round source of water for household use and for livestock. Groundwater is also widely used for irrigated agriculture and for lawns and gardens. In some settings, groundwater withdrawals could directly affect senior water-rights holders, stream flows, the availability of irrigation water, and the health of aquatic ecosystems. Efficient water management in these areas requires a well-founded understanding of the groundwater systems.

In 2009, the Montana State Legislature established the Ground Water Investigation Program (GWIP) within the Montana Bureau of Mines and Geology (MBMG) to conduct detailed groundwater investigations in specific areas with the most serious concerns. Over 40 projects have been nominated and prioritized by the Groundwater Steering Committee. Seven investigations were initiated in 2009. Five additional areas were selected to begin during 2011 and 2012. Each investigation is expected to take from 1 to 3 years to complete.

The results of each study will include a detailed report describing the hydrogeologic system of the area and a comprehensive set of data. These products are intended to provide a more detailed understanding of the groundwater system and tools which can then be used by regulators, senior water-rights holders, new water-rights applicants, and other stakeholders, to make informed water management decisions and to help anticipate hydrogeologic effects from changes in land use.

Cross section of aquifers in the Flathead River valley