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 near Puget Sound, Pierce and King Counties, Washington. A steady-state model version was constructed to simulate equilibrium conditions, while a transient model version was constructed to simulate monthly variability from January 2005 to December 2015. The model was used to simulate several hydrologic scenarios. This data release contains the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20245026v2).

A three-dimensional groundwater flow model, constructed in MODFLOW-NWT, was developed to evaluate the groundwater flow system near Puget Sound, Pierce and King Counties, Washington. A steady-state model version was constructed to simulate equilibrium conditions, while a transient model version was constructed to simulate monthly variability from January 2005 to December 2015. The model was used to simulate several hydrologic scenarios. This data release contains the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20245026v2).

A three-dimensional groundwater flow model was developed in 1997 to evaluate the groundwater flow system at Puget Sound Naval Shipyard, Naval Base Kitsap, Bremerton, Washington (https://pubs.er.usgs.gov/publication/wri964147). In 2016, a regional groundwater flow model for the greater Kitsap Peninsula was developed (https://pubs.er.usgs.gov/publication/sir20165052). Using information from the 2016 regional model, the 1997 groundwater flow model for the Puget Sound Naval Shipyard was updated with a new interpretation of the underlying hydrogeologic units, a refined model grid, and improved recharge estimates. A steady-state model version was constructed in MODFLOW-NWT to simulate equilibrium conditions. MODPATH forward and backward particle tracking simulations were then run using output from the steady-state MODFLOW-NWT model. This data release contains the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/ofr20161135).

A three-dimensional groundwater flow model was developed in 1997 to evaluate the groundwater flow system at Puget Sound Naval Shipyard, Naval Base Kitsap, Bremerton, Washington (https://pubs.er.usgs.gov/publication/wri964147). In 2016, a regional groundwater flow model for the greater Kitsap Peninsula was developed (https://pubs.er.usgs.gov/publication/sir20165052). Using information from the 2016 regional model, the 1997 groundwater flow model for the Puget Sound Naval Shipyard was updated with a new interpretation of the underlying hydrogeologic units, a refined model grid, and improved recharge estimates. A steady-state model version was constructed in MODFLOW-NWT to simulate equilibrium conditions. MODPATH forward and backward particle tracking simulations were then run using output from the steady-state MODFLOW-NWT model. This data release contains the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/ofr20161135).

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).

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 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).

The U.S. Geological Survey, in cooperation with the U.S. Department of the Navy, developed several 3-D groundwater flow models for used with MODFLOW-2005, MODFLOW-NWT, and SEAWAT model codes to evaluate variable-density groundwater flow and contaminant transport in Operable Unit 1 on Naval Base Kitsap in Keyport, Washington. Chlorinated volatile organic compounds (CVOCs) have migrated to groundwater beneath a former 9-acre landfill at Operable Unit 1 (OU-1). The three predominant ground-water contaminants are the chloroethene compounds trichloroethene (TCE), cis-1,2-dichloroethene (cis-DCE), and vinyl chloride (VC). A need for remedial action was identified because some of the contaminants present a potential risk to humans primarily through drinking contaminated groundwater or through ingesting seafood harvested from contaminated surface water. An ongoing effort with the U.S. Navy and U.S. Geological Survey (USGS) began in 1995 by evaluating the effectiveness of natural attenuation processes for removing and controlling the migration of CVOCs in ground water at OU-1. Additional collection of geochemical and contaminant concentration data demonstrated that biodegradation of CVOCs in shallow groundwater at OU-1 is substantial and prevents most of the mass of dissolved-phase CVOCs in groundwater beneath the landfill from discharging to surface water. However, dissolved-phase contaminant concentrations in the hundreds of milligrams per liter continue to persist in localized areas of OU-1. Data suggest that residual sources of chloroethenes in the form of non-aqueous phase liquid remain at the site, and that biodegradation is only partly effective at reducing the dissolved-phase contaminants that are generated from these sources. In 2018 an additional USGS effort was begun to simulate variable-density groundwater flow and contaminant transport in the vicinity of OU-1 using a revised hydrogeologic model of the site and a refined delineation of persistent contaminant sources. MODFLOW-2005 and MODFLOW-NWT model codes were used to calibrate a new model. Then groundwater flow and contaminant transport models were developed using SEAWAT-Version 4, a computer program based on MODFLOW and MT3DMS, to simulate three-dimensional variable-density groundwater flow coupled with multi-species solute transport. These models were used to simulate the direction and rate of groundwater flow near OU-1, estimate the CVOC mass in groundwater and the rate of mass loading, and assess possible remedial activities at OU-1. 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/sir20205066).