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 previously developed steady state three-dimensional groundwater flow (MODFLOW-2005) and advective transport (MODPATH6) model was used to examine subsurface nitrate transport to wells and receiving streams in two subcatchments contributing to the Upper Chester River, Maryland. Multiple scenarios of flow and transport parameter fields (recharge, hydraulic conductivity, and porosity) were previously calibrated against groundwater levels, stream discharge measurements, and atmospheric tracer measurements, as described in https://doi.org/10.1016/j.jhydrol.2018.02.006; those multiple scenarios are also available as a USGS data release (https://doi.org/10.5066/F7SN087R). Two of the flow and transport scenarios calibrated in Zell et al. (2018) were selected to simulate nitrate transport, with MODPATH6 files updated as necessary to represent advective transport from observation wells with subsurface nitrate measurements. The development of the model input and output files included in this data release and the application of the models to nitrate transport simulation are documented in the Journal of Environmental Quality article (https://doi.org/10.2134/jeq2018.11.0408).

A previously developed steady state three-dimensional groundwater flow (MODFLOW-2005) and advective transport (MODPATH6) model was used to examine subsurface nitrate transport to wells and receiving streams in two subcatchments contributing to the Upper Chester River, Maryland. Multiple scenarios of flow and transport parameter fields (recharge, hydraulic conductivity, and porosity) were previously calibrated against groundwater levels, stream discharge measurements, and atmospheric tracer measurements, as described in https://doi.org/10.1016/j.jhydrol.2018.02.006; those multiple scenarios are also available as a USGS data release (https://doi.org/10.5066/F7SN087R). Two of the flow and transport scenarios calibrated in Zell et al. (2018) were selected to simulate nitrate transport, with MODPATH6 files updated as necessary to represent advective transport from observation wells with subsurface nitrate measurements. The development of the model input and output files included in this data release and the application of the models to nitrate transport simulation are documented in the Journal of Environmental Quality article (https://doi.org/10.2134/jeq2018.11.0408).

A steady state three-dimensional groundwater flow (MODFLOW-2005) and advective transport (MODPATH6) model was developed to examine subsurface travel times to wells and receiving streams in two subcatchments contributing to the Upper Chester River, Maryland. The model was calibrated to conditions from 1990 to 2005, the period for which groundwater levels, stream discharge measurements, and atmospheric tracer measurements were jointly available. Six calibrated model scenarios were generated and paired with First Order Second Moment (FOSM) linear uncertainty analysis tools to evaluate (i) the uncertainty of base-flow age estimates as well as (ii) the worth of future data collection. The development of the model input and output files included in this data release are documented in the Journal of Hydrology article (https://doi.org/10.1016/j.jhydrol.2018.02.006).

A steady state three-dimensional groundwater flow (MODFLOW-2005) and advective transport (MODPATH6) model was developed to examine subsurface travel times to wells and receiving streams in two subcatchments contributing to the Upper Chester River, Maryland. The model was calibrated to conditions from 1990 to 2005, the period for which groundwater levels, stream discharge measurements, and atmospheric tracer measurements were jointly available. Six calibrated model scenarios were generated and paired with First Order Second Moment (FOSM) linear uncertainty analysis tools to evaluate (i) the uncertainty of base-flow age estimates as well as (ii) the worth of future data collection. The development of the model input and output files included in this data release are documented in the Journal of Hydrology article (https://doi.org/10.1016/j.jhydrol.2018.02.006).

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.

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.

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 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.