A new groundwater flow model was created for Dane County, Wisconsin, to replace an earlier model developed in the 1990s by the Wisconsin Geological and Natural History Survey (WGNHS) and the U.S. Geological Survey (USGS). This modeling study was conducted cooperatively by the WGNHS, the Capital Area Regional Planning Commission, and the USGS. Although the overall conceptual model of the groundwater system remains largely unchanged, the incorporation of newly acquired, high-quality datasets, recent research findings, and improved modeling and calibration techniques have led to the development of a much more detailed and sophisticated model representation of the groundwater system. The new model is three-dimensional and transient, and conceptualizes the county’s hydrogeology as a 12-layer system including all major unlithified and bedrock hydrostratigraphic units and two high-conductivity horizontal fracture zones.

A MODFLOW-NWT model was used to simulate the water budget for Haskell Lake and Tower Creek in WI using the Lake, Streamflow Routing, and Unsaturated Zone Flow packages. Particle tracking was performed with the MODFLOW solution (using MODPATH 6). This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20205024).

A MODFLOW-NWT model was used to simulate the water budget for Haskell Lake and Tower Creek in WI using the Lake, Streamflow Routing, and Unsaturated Zone Flow packages. Particle tracking was performed with the MODFLOW solution (using MODPATH 6). This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20205024).

A previously developed groundwater flow model (https://doi.org/10.3133/sir20185035) was modified and used as the primary tool to assess groundwater availability in the Ozark Plateaus aquifer system which is an important source for municipal, industrial, agricultural, and domestic water supply needs across much of southern Missouri and northern Arkansas, and smaller areas of southeastern Kansas and northeastern Oklahoma. The new model was developed to access changes in simulated hydrologic budget components at the regional scale to quantify hydrologic changes across the Ozark system. The model benefits current and future investigations that involve groundwater-withdrawal scenarios, optimization, particle transport, and monitoring network analysis. Recent short-term drought conditions have emphasized the need to better understand the delicate balance between abundance, sustainability and scarcity. The model also is critical to the ongoing work to quantify groundwater availability in the Ozark aquifer system. The groundwater model simulated 116 years (1900—2016) of historical hydrologic conditions, 45 years (2016-2060) of potential future hydrologic conditions, and the response of the groundwater system to changes in stress. Stress applied to the groundwater system included changes in recharge and increased groundwater withdrawals for water supply. Semi-seasonal stress periods were simulated from the later part of 1991 through 2060 to represent higher demand and lower recharge in the spring and summer months, and lower demand and higher recharge in the fall and winter months. Three scenarios were developed to simulate potential future conditions and assess the potential effects on the hydrologic system and availability of water resources. For each scenario, changes in water levels and hydrologic budget components were evaluated from predevelopment (1900) to present (2016), and 44 years into the future (2060). This USGS data release contains all of the input and output files for the model and the calibration and scenario simulations described in the associated professional paper (https://doi.org/10.3133/pp1854). This data release also includes (1) MODFLOW-NWT (v. 1.1.2) source code, (2) PEST++ source code, and (3) processing Python scripts and associated instruction files for parameter estimation and model calibration using PEST++.

A new groundwater flow model for western Chippewa County, Wisconsin has been developed by the Wisconsin Geological and Natural History Survey (WGNHS) and the U.S. Geological Survey (USGS). An analytic element GFLOW model was constructed and calibrated to generate hydraulic boundary conditions for the perimeter of the more detailed three-dimensional MODFLOW-NWT model. This three-dimensional model uses the USGS MODFLOW-NWT finite difference code, a standalone version of MODFLOW-2005 that incorporates the Newton (NWT) solver. The model conceptualizes the hydrogeology of western Chippewa County as a six-layer system which includes several hydrostratigraphic units. The model explicitly simulates groundwater-surface-water interaction with streamflow routing. Model input included recent estimates of aquifer hydraulic conductivities and a spatial groundwater recharge distribution developed using a GIS-based soil-water-balance model for the study area. Groundwater withdrawals from pumping were simulated for 269 high-capacity wells across the entire model domain, which includes western Chippewa County and portions of eastern Dunn County and southeastern Barron County. Model calibration used the parameter estimation code PEST, and calibration targets included heads and stream flows. Calibration f focused on the period from during 2011 to 2013 when the largest amount of calibration data were available. Following calibration, the model was applied to two distinct scenarios; one evaluating hydraulic impacts of more intensive industrial sand mining and the second evaluating the hydraulicimpacts of more intensive agricultural irrigation practices. Each scenario was developed with input by Chippewa County and a stakeholder group established for this study, and designed to represent reasonable future build-out conditions for both mining and irrigatedagriculture. The mining scenario underscores the potential hydraulic impacts related to changing land-use practices (i.e., hilltops and farm land becoming sand mines), while the irrigated agriculture scenario illustrates the potential hydraulic impacts of intensifying existing land-use practices (i.e., installing new wells to irrigate farm fields).

A new groundwater flow model for western Chippewa County, Wisconsin has been developed by the Wisconsin Geological and Natural History Survey (WGNHS) and the U.S. Geological Survey (USGS). An analytic element GFLOW model was constructed and calibrated to generate hydraulic boundary conditions for the perimeter of the more detailed three-dimensional MODFLOW-NWT model. This three-dimensional model uses the USGS MODFLOW-NWT finite difference code, a standalone version of MODFLOW-2005 that incorporates the Newton (NWT) solver. The model conceptualizes the hydrogeology of western Chippewa County as a six-layer system which includes several hydrostratigraphic units. The model explicitly simulates groundwater-surface-water interaction with streamflow routing. Model input included recent estimates of aquifer hydraulic conductivities and a spatial groundwater recharge distribution developed using a GIS-based soil-water-balance model for the study area. Groundwater withdrawals from pumping were simulated for 269 high-capacity wells across the entire model domain, which includes western Chippewa County and portions of eastern Dunn County and southeastern Barron County. Model calibration used the parameter estimation code PEST, and calibration targets included heads and stream flows. Calibration f focused on the period from during 2011 to 2013 when the largest amount of calibration data were available. Following calibration, the model was applied to two distinct scenarios; one evaluating hydraulic impacts of more intensive industrial sand mining and the second evaluating the hydraulicimpacts of more intensive agricultural irrigation practices. Each scenario was developed with input by Chippewa County and a stakeholder group established for this study, and designed to represent reasonable future build-out conditions for both mining and irrigatedagriculture. The mining scenario underscores the potential hydraulic impacts related to changing land-use practices (i.e., hilltops and farm land becoming sand mines), while the irrigated agriculture scenario illustrates the potential hydraulic impacts of intensifying existing land-use practices (i.e., installing new wells to irrigate farm fields).

A groundwater-flow model was developed for the Bad River Watershed and surrounding area by using the U.S. Geological Survey (USGS) finite-difference code MODFLOW–NWT. The model simulates steady-state groundwater-flow and base flow in streams by using the streamflow routing (SFR) package. The model was calibrated to groundwater levels and base flows obtained from the USGS National Water Information System (NWIS) database, and groundwater levels obtained from the Wisconsin Department of Natural Resources and Bad River Band well-construction databases. Calibration was performed via nonlinear regression by using the parameter-estimation software suite PEST.

Groundwater flow models have the potential to predict spatial groundwater discharge dynamics within river networks, but models are often not evaluated against discharge dynamics. The objective of this study was to understand the variation in simulated discharge dynamics (discharge location, flowpath depth, and subsurface travel time) for models with common, but varying frameworks and assumptions. The University of Connecticut in collaboration with the United States Geological Survey developed a groundwater flow model (MODFLOW-NWT) for the Farmington River Watershed (1,570 km2) in the northeastern United States and systematically varied the type of typical calibration data (well head and stream elevation); calibration parameters; parameters related to permeability of the surficial materials, bedrock, and riverbed sediments; control of river-aquifer exchange directionality; and model resolution. Each model variation has an associated particle tracking (MODPATH) model. Subsequent work, not described in this model archive, compared with simulated spatial patterns of groundwater discharge with patterns observed with hand-held thermal infrared imagery. This dataset contains model inputs and outputs, post-processing python scripts, and pest calibration input files for 12 model variations described in the associated journal article (https://doi.org/10.1029/2020WR028027)

Groundwater flow models have the potential to predict spatial groundwater discharge dynamics within river networks, but models are often not evaluated against discharge dynamics. The objective of this study was to understand the variation in simulated discharge dynamics (discharge location, flowpath depth, and subsurface travel time) for models with common, but varying frameworks and assumptions. The University of Connecticut in collaboration with the United States Geological Survey developed a groundwater flow model (MODFLOW-NWT) for the Farmington River Watershed (1,570 km2) in the northeastern United States and systematically varied the type of typical calibration data (well head and stream elevation); calibration parameters; parameters related to permeability of the surficial materials, bedrock, and riverbed sediments; control of river-aquifer exchange directionality; and model resolution. Each model variation has an associated particle tracking (MODPATH) model. Subsequent work, not described in this model archive, compared with simulated spatial patterns of groundwater discharge with patterns observed with hand-held thermal infrared imagery. This dataset contains model inputs and outputs, post-processing python scripts, and pest calibration input files for 12 model variations described in the associated journal article (https://doi.org/10.1029/2020WR028027)

A MODFLOW-NWT groundwater flow model was developed to simulate groundwater movement in the area around Anvil Lake, and groundwater inputs and outputs from the lake from 1980 to 2014. Surface-water hydrology was simulated using the lake package. The MODFLOW model was first calibrated for steady-state conditions, or "average" conditions corresponding to January 1, 1980, to December 31, 2014 to estimate spatial hydrogeologic properties. Following the steady-state calibration, the model was applied in transient mode to estimate average monthly hydrologic conditions (groundwater inputs and outputs) for each year from 1980 to 2014.