GWIP supports science-based water management in Montana by answering site-specific questions that are prioritized and assigned by the Montana Ground Water Steering Committee MCA 2-15-1523, as mandated by the Montana Legislature and authorized in MCA 85-2-525. To meet this goal, GWIP conducts research on specific hydrogeologic issues in areas that are ranked as the most urgent within the State.

Groundwater withdrawals can directly affect senior water-rights holders, streamflows, the availability of irrigation water, and the health of aquatic ecosystems. Efficient water management requires a scientifically based understanding of the groundwater systems.

GWIP projects have included water resource issues such as:

• Cumulative effects of existing and proposed water development on groundwater and streamflow,
• Effects to groundwater and surface water from changes in irrigation practices or land use,
• Groundwater availability for residential, commercial, and agricultural development,
• Possible effects of energy development on groundwater resources,
• Evaluation of mitigation/offset plans in closed basins, and
• Water-quality impacts on groundwater and surface waters from land use changes.

The results of each investigation include:

• A detailed report describing the hydrogeologic system of the area, addressing the immediate water-resource question and implications for future stresses as appropriate,
• Typically, a groundwater model that is available for use in future analyses, and
• A comprehensive set of data available through the Ground Water Information Center (GWIC).

These products are used by regulators, senior water-rights holders, new water-rights applicants, and other stakeholders to make better-informed water management decisions.

Groundwater modeling simulates the natural system and provides a tool to evaluate changes in land use, increased water demand, and the effects of drought on Montana’s hydrology.

Water-quality sampling is used to determine aquifer chemistry and the effects of increased residential and agricultural changes on water quality.

Measuring groundwater levels in the Flathead Valley provides information on aquifer response and groundwater flow directions.

Stream flow measurements of the Gallatin River will help determine gaining/losing sections of the river near Big Sky.