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.

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 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.

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, steady-state groundwater-flow model representing 2003-13 mean hydrologic conditions was developed and calibrated to assess groundwater and lake-water exchanges and the effects of groundwater withdrawals and precipitation on water levels in lakes in the northeast Twin Cities Metropolitan Area, Minnesota. The USGS groundwater-flow model program MODFLOW-NWT version 1.0.8 was used to simulate groundwater flow in the approximately 1,000-square-mile area of the northeast Twin Cities Metropolitan Area and western Wisconsin. Water levels were below normal for several lakes in the northeast Twin Cities Metropolitan Area during 2003 through 2013. Previous periods of low lake-water levels generally correlate with periods of below-normal precipitation but increases in groundwater withdrawals and land-use changes have put into question whether recent lake-water-level declines are due solely to declines in precipitation. The groundwater-flow model was developed to provide a thorough understanding of regional groundwater and surface-water exchanges under different groundwater withdrawal and precipitation scenarios. This USGS data release contains all of the input and output files for the simulations described in the associated U.S. Geological Survey Scientific Investigations Report 2016-5139B (https://doi.org/10.3133/sir20165139B). This data release also contains input and output data for ancillary soil-water balance (SWB) models used to simulate runoff to a subset of lakes and areal groundwater recharge.

A three-dimensional, steady-state groundwater-flow model representing 2003-13 mean hydrologic conditions was developed and calibrated to assess groundwater and lake-water exchanges and the effects of groundwater withdrawals and precipitation on water levels in lakes in the northeast Twin Cities Metropolitan Area, Minnesota. The USGS groundwater-flow model program MODFLOW-NWT version 1.0.8 was used to simulate groundwater flow in the approximately 1,000-square-mile area of the northeast Twin Cities Metropolitan Area and western Wisconsin. Water levels were below normal for several lakes in the northeast Twin Cities Metropolitan Area during 2003 through 2013. Previous periods of low lake-water levels generally correlate with periods of below-normal precipitation but increases in groundwater withdrawals and land-use changes have put into question whether recent lake-water-level declines are due solely to declines in precipitation. The groundwater-flow model was developed to provide a thorough understanding of regional groundwater and surface-water exchanges under different groundwater withdrawal and precipitation scenarios. This USGS data release contains all of the input and output files for the simulations described in the associated U.S. Geological Survey Scientific Investigations Report 2016-5139B (https://doi.org/10.3133/sir20165139B). This data release also contains input and output data for ancillary soil-water balance (SWB) models used to simulate runoff to a subset of lakes and areal groundwater recharge.

A three dimensional groundwater flow model (MODFLOW-NWT) was developed to examine the effects of changes to engineering controls and Lake Michigan surface water levels on the distribution of ponded water near Long Lake in Indiana Dunes National Lakeshore, near Gary, Indiana. The steady state model was calibrated to relatively low groundwater level condition of October 2002 and a relatively high groundwater level condition of March 2011. Scenario models were generated that examined the effects of (1) removing the beaver dams in US-12 ditch, (2) discontinuing seepage of water from the filtration pond east of East Long Lake, (3) discontinuing discharge from US-12 ditch to the Gary Sanitary District sewer system, (4) decreasing discharge from US-12 ditch to the Gary Sanitary District sewer system, (5) connecting East Long Lake and West Long Lake, (6) deepening County Line Road ditch, and (7) raising and lowering the water level of Lake Michigan. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://pubs.usgs.gov/sir/2013/5003/).

A three dimensional groundwater flow model (MODFLOW-NWT) was developed to examine the effects of changes to engineering controls and Lake Michigan surface water levels on the distribution of ponded water near Long Lake in Indiana Dunes National Lakeshore, near Gary, Indiana. The steady state model was calibrated to relatively low groundwater level condition of October 2002 and a relatively high groundwater level condition of March 2011. Scenario models were generated that examined the effects of (1) removing the beaver dams in US-12 ditch, (2) discontinuing seepage of water from the filtration pond east of East Long Lake, (3) discontinuing discharge from US-12 ditch to the Gary Sanitary District sewer system, (4) decreasing discharge from US-12 ditch to the Gary Sanitary District sewer system, (5) connecting East Long Lake and West Long Lake, (6) deepening County Line Road ditch, and (7) raising and lowering the water level of Lake Michigan. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://pubs.usgs.gov/sir/2013/5003/).