This model archive data release includes all models used to characterize the magnitude, spatial distribution and timing of groundwater (GW) flow through lakebed sediments to Upper Klamath Lake (UKL), Oregon, described in the associated journal article (https://doi.org/10.1016/j.scitotenv.2020.142768). One-dimensional vertical models of GW flow (MODFLOW-2005) and solute transport (MT3D-USGS) were calibrated (UCODE) to 2014 observed dissolved silica (Si, 0.2-micron filtered) porewater concentrations in the upper 0.1 m of lakebed sediment to estimate GW flow and Si exchange across the lakebed interface. The Si-based calibrated GW flow rates were then used in conjunction with observed dissolved phosphate-phosphorus (PP) porewater concentrations in the upper 0.1 m of lakebed sediment to estimate the amount of PP reacted during upward flow through the lakebed sediment and the PP discharge to the lake. One-dimensional, vertical GW flow and heat transport models (VS2DH) were calibrated (UCODE) to 2015 and 2017 observed lakebed temperatures to provide estimates of GW-inflow rates at multiple UKL locations. Calibrated GW inflows were greatest in the spring and decreased through the summer. The magnitude and timing of the GW-lake water exchange estimates obtained from these methods were compared to rates obtained from a generalized cross-sectional GW flow model (MODFLOW-NWT) with time-varying recharge. The cross-sectional GW flow model demonstrated that snow-melt GW recharge could be transported rapidly to the lake due to the relatively high permeability and low specific storage of the surrounding volcanic rocks explaining the greater GW discharge to the lake in the spring. This USGS data release contains all the input and output files for the simulations described in the associated journal article (https://doi.org/10.1016/j.scitotenv.2020.142768).

This data release contains a three-dimensional groundwater flow model with example applications using MODFLOW-2000. The calibrated model is able to simulate observed decadal-scale climate-driven fluctuations in the groundwater system as well as observed shorter-term pumping-related fluctuations. Example model simulations show that the timing and location of the effects of groundwater pumping vary markedly depending on the pumping location. The complete description for the models in Gannett et al., 2012.

This data release contains a three-dimensional groundwater flow model with example applications using MODFLOW-2000. The calibrated model is able to simulate observed decadal-scale climate-driven fluctuations in the groundwater system as well as observed shorter-term pumping-related fluctuations. Example model simulations show that the timing and location of the effects of groundwater pumping vary markedly depending on the pumping location. The complete description for the models in Gannett et al., 2012.

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 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).

The U.S. Geological Survey (USGS), in cooperation with the Oklahoma Water Resources Board (OWRB), constructed a finite-difference numerical groundwater-flow model of the Washita River aquifer by using MODFLOW-2005 (Harbaugh, 2005) with the Newton formulation solver (MODFLOW-NWT). The 1973 Oklahoma Groundwater Law requires that the OWRB conduct hydrologic investigations of the State’s aquifers to determine the maximum annual yield (MAY) for each groundwater basin. The MAY is defined as the total amount of fresh groundwater that can be annually withdrawn while allowing a minimum 20-year life of that groundwater basin. For alluvium and terrace groundwater basins, the life requirement is satisfied if, after 20 years of MAY withdrawals, 50 percent of the groundwater basin (hereinafter referred to as an “aquifer”) retains a saturated thickness of at least 5 ft. Once a MAY has been established, the amount of land owned or leased by a groundwater-use permit applicant determines the annual volume of water allocated to that groundwater-use permit applicant. The annual volume of groundwater allocated per acre of land is known as the equal-proportionate-share (EPS) pumping rate. The OWRB issued a final order on November 13, 1990, that established the MAY (81,840 and 46,935 acre-feet per year [acre-ft/yr]) and EPS pumping rate (1.5 and 1.0 acre-foot per acre per year) for reaches 3 and 4, respectively, of the Washita River aquifer in southern Oklahoma. Because more than 20 years have elapsed since the final order was issued, the USGS, in cooperation with the OWRB, conducted an updated hydrologic investigation and evaluated the effects of potential groundwater withdrawals on groundwater flow and availability in the Washita River aquifer in southern Oklahoma. Reach 3 extends from near Anadarko, Okla., to Alex, Okla., and reach 4 extends from near Alex to south of Davis, Okla. Twenty-four simulations are included in this data release: a simulation for the calibrated numerical groundwater-flow model, 18 scenario simulations to evaluate the EPS pumping rate, 4 scenario simulations to evaluate groundwater storage over a 50-year period, and 1 scenario simulation to evaluate effects of a hypothetical drought. 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/sir20235072).

The U.S. Geological Survey (USGS), in cooperation with the Oklahoma Water Resources Board (OWRB), constructed a finite-difference numerical groundwater-flow model of the Washita River aquifer by using MODFLOW-2005 (Harbaugh, 2005) with the Newton formulation solver (MODFLOW-NWT). The 1973 Oklahoma Groundwater Law requires that the OWRB conduct hydrologic investigations of the State’s aquifers to determine the maximum annual yield (MAY) for each groundwater basin. The MAY is defined as the total amount of fresh groundwater that can be annually withdrawn while allowing a minimum 20-year life of that groundwater basin. For alluvium and terrace groundwater basins, the life requirement is satisfied if, after 20 years of MAY withdrawals, 50 percent of the groundwater basin (hereinafter referred to as an “aquifer”) retains a saturated thickness of at least 5 ft. Once a MAY has been established, the amount of land owned or leased by a groundwater-use permit applicant determines the annual volume of water allocated to that groundwater-use permit applicant. The annual volume of groundwater allocated per acre of land is known as the equal-proportionate-share (EPS) pumping rate. The OWRB issued a final order on November 13, 1990, that established the MAY (81,840 and 46,935 acre-feet per year [acre-ft/yr]) and EPS pumping rate (1.5 and 1.0 acre-foot per acre per year) for reaches 3 and 4, respectively, of the Washita River aquifer in southern Oklahoma. Because more than 20 years have elapsed since the final order was issued, the USGS, in cooperation with the OWRB, conducted an updated hydrologic investigation and evaluated the effects of potential groundwater withdrawals on groundwater flow and availability in the Washita River aquifer in southern Oklahoma. Reach 3 extends from near Anadarko, Okla., to Alex, Okla., and reach 4 extends from near Alex to south of Davis, Okla. Twenty-four simulations are included in this data release: a simulation for the calibrated numerical groundwater-flow model, 18 scenario simulations to evaluate the EPS pumping rate, 4 scenario simulations to evaluate groundwater storage over a 50-year period, and 1 scenario simulation to evaluate effects of a hypothetical drought. 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/sir20235072).

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).