Ground Water Investigation Program — GWIP
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, as mandated by the Montana Legislature andauthorized 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.
The results of each study include:
- ✓ A detailed report describing the hydrogeologic system of the area, addresses the immediate water resource question and implications for future stresses as appropriate,
- ✓ Typically, a groundwater model that is available for use in future analyses.
- ✓ A comprehensive set of data available through the MBMG website.
These products are used by regulators, senior water-rights holders, new water-rights applicants, and other stakeholders to make better-informed water management decisions.
In Montana, groundwater is essential for safe drinking water supplies and for economic growth. Every day, approximately 272,000,000 gallons (835 acre-feet) are extracted from Montana's aquifers. 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. Groundwater withdrawals can directly affect senior water-rights holders, stream flows, the availability of irrigation water, and the health of aquatic ecosystems. Efficient water management requires a scientifically based understanding of the groundwater systems.
Nominated projects have included water resource issues such as:
- Cumulative effects of existing and proposed water development on groundwater and stream flow,
- Impacts to groundwater and surface water from changes in irrigation practices or land use,
- Groundwater availability for residential and agricultural development,
- Possible impacts of energy development on groundwater resources,
- Implementation of aquifer storage and recovery (ASR), and
- Evaluation of mitigation/offset plans in closed basins.
Numerical groundwater flow models are used to evaluate changes in land use on groundwater and surface water. This graph shows the potential effects of changing irrigation practices in the Waterloo area on nearby spring fed streams. The model predicts that lining canals and converting from flood to pivot irrigation can result in a reduction of about 13 cfs or 21% of mean August flow in Parson’s Slough and Willow Springs.