MODFLOW-NWT model used to assess groundwater availability in the uppermost principal aquifer systems of the Williston structural basin, United States and Canada

A three-dimensional groundwater flow model was developed to characterize groundwater resources the uppermost principal aquifers in the Williston structural basin in parts of Montana, North Dakota, and South Dakota in the United States and of Manitoba and Saskatchewan in Canada as part of a detailed assessment of the groundwater availability of the area. The uppermost principal aquifers are comprised of the glacial, lower Tertiary, and Upper Cretaceous aquifer systems. The model was developed as a part of the U.S. Geological Survey Water Availability and Use Science Program's effort to conduct large-scale multidisciplinary regional studies of groundwater availability. The numerical model is intended to be used to (1) simulate hydrologic [...]