This groundwater-flow model archive contains all of the input and output files for an inset MODFLOW-NWT model extracted from the northern (Wisconsin) half of a published USGS steady-state regional model of the Upper Fox River Basin in the U.S. Upper Midwest. The construction and details of the published USGS steady-state model of the Upper Fox River Basin is outlined in the U.S. Geological Survey Scientific Investigations Report 2018-5038 (https://doi.org/10.3133/sir20185038). The regional model is archived in the data release at https://doi.org/10.5066/F76D5R5V. The extracted model was used to demonstrate an innovative new method for delinating fen distribution and discharge using the MODFLOW UZF package. The extracted model incorporates the Mukwonago River Basin, a 10-digit hydrologic unit code (HUC10) basin occupying 86.2 mi2 (223 km2) in southeastern Wisconsin. The extracted model was used to demonstrate how regional and local flow patterns can be enhanced by adding a version of the UZF file that automatically inserts “seepage drains” in cells where the water table is near the land surface (within the “undulation depth”). Details on the extracted model construction and calibration, including preparation of the “stripped-down” UZF file central to the proposed fen delineation method can be found in the supporting information of the journal article in Groundwater (https://doi.org/10.1111/gwat.12931). This USGS data release contains all of the input and output files for the simulations described in the journal article in Groundwater (https://doi.org/10.1111/gwat.12931).

A three-dimensional, groundwater flow model (MODFLOW-NWT) was developed to examine groundwater storage changes in the Quincy Basin, Washington. The model was calibrated to conditions from 1920 to 2013. The model was used to (1) determine the change in groundwater storage from 1920 to 2013 , and (2) simulate the potential effects of increases in pumping, decrease in irrigation recharge, and increases in streamflow in Crab Creek by 100 cubic feet per second and 500 cubic feet per second. 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/sir20185162).

A three-dimensional, groundwater flow model (MODFLOW-NWT) was developed to examine groundwater storage changes in the Quincy Basin, Washington. The model was calibrated to conditions from 1920 to 2013. The model was used to (1) determine the change in groundwater storage from 1920 to 2013 , and (2) simulate the potential effects of increases in pumping, decrease in irrigation recharge, and increases in streamflow in Crab Creek by 100 cubic feet per second and 500 cubic feet per second. 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/sir20185162).

A three-dimensional groundwater flow model, constructed in MODFLOW-NWT, was developed to evaluate the groundwater flow system of the Kitsap Peninsula, west-central Washington. A transient model was constructed to simulate groundwater flow for January 1985–December 2012 using annual stress periods for 1985–2004 and monthly stress periods for 2005–2012. The model was used to simulate six hydrologic scenarios, including simulations of a steady-state system, no-pumping and return flows, 15-percent increase in current withdrawals in all wells, 80-percent decrease in outdoor water to simulate effects of conservation efforts, 15-percent decrease in recharge from precipitation to simulate a drought, and particle tracking to determine flow paths. This data release contains the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20165052).

A three-dimensional groundwater flow model, constructed in MODFLOW-NWT, was developed to evaluate the groundwater flow system of the Kitsap Peninsula, west-central Washington. A transient model was constructed to simulate groundwater flow for January 1985–December 2012 using annual stress periods for 1985–2004 and monthly stress periods for 2005–2012. The model was used to simulate six hydrologic scenarios, including simulations of a steady-state system, no-pumping and return flows, 15-percent increase in current withdrawals in all wells, 80-percent decrease in outdoor water to simulate effects of conservation efforts, 15-percent decrease in recharge from precipitation to simulate a drought, and particle tracking to determine flow paths. This data release contains the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20165052).

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 numerical groundwater flow model of the Hualapai Valley Basin, using MODFLOW-NWT, was developed to assist water-resource managers in understanding the potential effects of projected groundwater withdrawals on groundwater levels in the basin. Hualapai Valley Basin is a broad, internally drained, intermountain desert basin in Mohave County, northwestern Arizona. Basin-fill aquifers are the primary groundwater source for many desert communities, and the residents, commerce, and agriculture in and near to the Hualapai Valley Basin must rely on such groundwater to meet water needs. As in many parts of the western United States, population growth in this part of Arizona is substantial. From 2000 to 2018 the population of the City of Kingman, Arizona, grew from 20,069 to 30,314, an increase of 51 percent, whereas the population of Mohave County grew from 155,062 to 209,550, an increase of 35 percent. Water managers in Mohave County have raised concern about the potential for future groundwater development and additional stresses on the groundwater system in the Hualapai Valley Basin. In particular, the City of Kingman, Ariz., water supply is primarily groundwater withdrawn from the Kingman subbasin of the Hualapai Valley Basin, northeast of the city. The potential effects of future water development on the City of Kingman well field have become a top concern to regional water-resource managers. To address these concerns the Hualapai Valley Hydrologic Model (HVHM) simulates the hydrologic system for the years 1935 through 2219, including future withdrawal scenarios that simulate large-scale agricultural expansion with and without enhanced groundwater recharge from potential new infiltration basin projects. HVHM is a highly parameterized model (75,586 adjustable parameters) capable of simulating grid-scale variability in aquifer properties (for example, conductivity, specific yield, and specific storage) and system stresses (for instance, natural recharge and groundwater withdrawals). System stresses were partially adopted from a previously-published groundwater model (Tillman and others, 2013). Parameter estimation and uncertainty quantification were performed using an iterative ensemble smoother software (PESTPP-IES) to produce an ensemble of models fit to historical data. Two future scenarios were simulated with a subset of the posterior parameter ensemble comprising the 40 best-fit realizations. In scenario 1, future pumping was simulated to increase linearly from 2019 through 2029 and then held constant through 2219. Scenario 2 includes the same specified future pumping, but also simulates enhanced recharge at proposed infiltration basins throughout the Kingman subbasin beginning in 2019. 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/sir20215077).

A numerical groundwater flow model of the Hualapai Valley Basin, using MODFLOW-NWT, was developed to assist water-resource managers in understanding the potential effects of projected groundwater withdrawals on groundwater levels in the basin. Hualapai Valley Basin is a broad, internally drained, intermountain desert basin in Mohave County, northwestern Arizona. Basin-fill aquifers are the primary groundwater source for many desert communities, and the residents, commerce, and agriculture in and near to the Hualapai Valley Basin must rely on such groundwater to meet water needs. As in many parts of the western United States, population growth in this part of Arizona is substantial. From 2000 to 2018 the population of the City of Kingman, Arizona, grew from 20,069 to 30,314, an increase of 51 percent, whereas the population of Mohave County grew from 155,062 to 209,550, an increase of 35 percent. Water managers in Mohave County have raised concern about the potential for future groundwater development and additional stresses on the groundwater system in the Hualapai Valley Basin. In particular, the City of Kingman, Ariz., water supply is primarily groundwater withdrawn from the Kingman subbasin of the Hualapai Valley Basin, northeast of the city. The potential effects of future water development on the City of Kingman well field have become a top concern to regional water-resource managers. To address these concerns the Hualapai Valley Hydrologic Model (HVHM) simulates the hydrologic system for the years 1935 through 2219, including future withdrawal scenarios that simulate large-scale agricultural expansion with and without enhanced groundwater recharge from potential new infiltration basin projects. HVHM is a highly parameterized model (75,586 adjustable parameters) capable of simulating grid-scale variability in aquifer properties (for example, conductivity, specific yield, and specific storage) and system stresses (for instance, natural recharge and groundwater withdrawals). System stresses were partially adopted from a previously-published groundwater model (Tillman and others, 2013). Parameter estimation and uncertainty quantification were performed using an iterative ensemble smoother software (PESTPP-IES) to produce an ensemble of models fit to historical data. Two future scenarios were simulated with a subset of the posterior parameter ensemble comprising the 40 best-fit realizations. In scenario 1, future pumping was simulated to increase linearly from 2019 through 2029 and then held constant through 2219. Scenario 2 includes the same specified future pumping, but also simulates enhanced recharge at proposed infiltration basins throughout the Kingman subbasin beginning in 2019. 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/sir20215077).

A MODFLOW-NWT model was used to simulate long-term, average conditions in the regional, Columbia County groundwater system since about 1970. A GFLOW model was used to estimate regional boundary fluxes to the MODFLOW-NWT model domain