The U.S. Geological Survey in cooperation with the Upper Arkansas Water Conservancy District, created a numerical groundwater-flow model for the Wet Mountain Valley alluvial aquifer using the finite-difference MODFLOW code with the Newton formulation solver. This numerical groundwater-flow model simulates water-budget components, groundwater and surface-water interactions, and evaluates the potential effects of aquifer storage and recovery through an added recharge simulation. The numerical model was spatially discretized into two layers with 261 rows and 133 columns of square cells at 250 meters on each side, for a total of 20,007 active cells. The model was rotated by 36 degrees to the northwest to align with the orientation of the valley and the assumed groundwater-flow directions. The numerical model was temporally discretized into 241 stress periods. The first stress period simulates a mean steady-state period, and the subsequent 240 stress periods were transient and simulate each month from 2000 to 2019. This U.S. Geological Survey data release includes all of the necessary files to simulate the Wet Mountain Valley alluvial aquifer and potential flow paths within it as described in the associated Scientific Investigations Report (https://doi.org/10.3133/sir20245105).

The U.S. Geological Survey (USGS), in cooperation with the Air Force Civil Engineering Center, created a numerical groundwater-flow model for the Fountain Creek alluvial aquifer using the finite-difference MODFLOW code with the Newton formulation solver. This numerical groundwater-flow model simulates water-budget components, groundwater-flow directions, and groundwater-flow paths of the Fountain Creek alluvial aquifer. The numerical model was spatially discretized into a single layer with 291 rows and 254 columns of 200 by 200 feet size, and a total of 17,610 active cell. The numerical model was temporally discretized into 1 initial steady-state stress period representing the average conditions of the 240 monthly transient stress periods from 2000 to 2019. This USGS data release includes all the necessary files to simulate the Fountain Creek alluvial aquifer and potential flow paths within it as described in the associated USGS Scientific Investigations Report (https://doi.org/10.3133/sir20235119).

The U.S. Geological Survey (USGS), in cooperation with the Air Force Civil Engineering Center, created a numerical groundwater-flow model for the Fountain Creek alluvial aquifer using the finite-difference MODFLOW code with the Newton formulation solver. This numerical groundwater-flow model simulates water-budget components, groundwater-flow directions, and groundwater-flow paths of the Fountain Creek alluvial aquifer. The numerical model was spatially discretized into a single layer with 291 rows and 254 columns of 200 by 200 feet size, and a total of 17,610 active cell. The numerical model was temporally discretized into 1 initial steady-state stress period representing the average conditions of the 240 monthly transient stress periods from 2000 to 2019. This USGS data release includes all the necessary files to simulate the Fountain Creek alluvial aquifer and potential flow paths within it as described in the associated USGS Scientific Investigations Report (https://doi.org/10.3133/sir20235119).

This data release contains environmental tracer model inputs, outputs, and model results. Dataset includes environmental tracer concentrations, simulated recharge conditions (water temperature, excess air), and estimated groundwater residence times. This dataset supports an integrated hydrologic investigation of groundwater recharge processes and groundwater flow in the Wet Mountain Valley alluvial aquifer, Custer and Fremont Counties, Colorado. Data were collected by the U.S. Geological Survey in cooperation with the Upper Arkansas Water Conservancy District.

This data release contains environmental tracer model inputs, outputs, and model results. Dataset includes environmental tracer concentrations, simulated recharge conditions (water temperature, excess air), and estimated groundwater residence times. This dataset supports an integrated hydrologic investigation of groundwater recharge processes and groundwater flow in the Wet Mountain Valley alluvial aquifer, Custer and Fremont Counties, Colorado. Data were collected by the U.S. Geological Survey in cooperation with the Upper Arkansas Water Conservancy District.

This data release contains environmental tracer concentrations, modeled recharge conditions (water temperature, excess air), and resulting estimated groundwater residence times. This dataset supports an integrated hydrogeochemical investigation of solute sources, groundwater recharge processes, and groundwater flow in the Fountain Creek alluvial aquifer. The data release contains five comma separated value (CSV) files. The CSV files contain the model inputs (gas and tracer concentrations) and the model outputs (simulated recharge temperature, excess air, apparent groundwater age, and mean groundwater residence time). Data were collected in cooperation with the U.S. Air Force Civil Engineering Center.

This data release contains environmental tracer concentrations, modeled recharge conditions (water temperature, excess air), and resulting estimated groundwater residence times. This dataset supports an integrated hydrogeochemical investigation of solute sources, groundwater recharge processes, and groundwater flow in the Fountain Creek alluvial aquifer. The data release contains five comma separated value (CSV) files. The CSV files contain the model inputs (gas and tracer concentrations) and the model outputs (simulated recharge temperature, excess air, apparent groundwater age, and mean groundwater residence time). Data were collected in cooperation with the U.S. Air Force Civil Engineering Center.

A previously calibrated MODFLOW-NWT groundwater-flow model (https://doi.org/10.3133/sir20205118) was used to determine the effects of climate variability under a range of future climatic conditions on groundwater resources in the reach 1 of the Washita River alluvial aquifer in western Oklahoma. The study area focuses on reach 1 of the Washita River alluvial aquifer; the entire Washita River alluvial aquifer consists of four administrative sections, or reaches, that are designated as reaches 1–4 by the Oklahoma Water Resources Board (OWRB, 2012). To approximate a range in future base-flow conditions in reach 1 of the Washita River alluvial aquifer and base-flow into Foss Reservoir, the Coupled Model Intercomparison Project Phase 5 Global Climate Model climate data were downscaled to watershed scale using monthly Bias-Correction Spatial Disaggregation techniques. A time series of scaling factors was developed and spatially interpolated for three climate scenarios (central tendency, warmer/drier, and less warm-wetter) representing a range of future climate conditions for the period 2050–2079. These scaling factors were then applied to an existing soil-water-balance model (https://doi.org/10.3133/sir20205118) with climate data for the baseline period 1985–2014 to produce recharge and evapotranspiration estimations for this future period. The downscaled climate data were applied to the groundwater-flow model of the reach 1 of the Washita River alluvial aquifer using MODFLOW-NWT. This data release contains the input and output files for the scenarios described in the associated model documentation report (https://doi.org/10.3133/sir20245082).

A previously calibrated MODFLOW-NWT groundwater-flow model (https://doi.org/10.3133/sir20205118) was used to determine the effects of climate variability under a range of future climatic conditions on groundwater resources in the reach 1 of the Washita River alluvial aquifer in western Oklahoma. The study area focuses on reach 1 of the Washita River alluvial aquifer; the entire Washita River alluvial aquifer consists of four administrative sections, or reaches, that are designated as reaches 1–4 by the Oklahoma Water Resources Board (OWRB, 2012). To approximate a range in future base-flow conditions in reach 1 of the Washita River alluvial aquifer and base-flow into Foss Reservoir, the Coupled Model Intercomparison Project Phase 5 Global Climate Model climate data were downscaled to watershed scale using monthly Bias-Correction Spatial Disaggregation techniques. A time series of scaling factors was developed and spatially interpolated for three climate scenarios (central tendency, warmer/drier, and less warm-wetter) representing a range of future climate conditions for the period 2050–2079. These scaling factors were then applied to an existing soil-water-balance model (https://doi.org/10.3133/sir20205118) with climate data for the baseline period 1985–2014 to produce recharge and evapotranspiration estimations for this future period. The downscaled climate data were applied to the groundwater-flow model of the reach 1 of the Washita River alluvial aquifer using MODFLOW-NWT. This data release contains the input and output files for the scenarios described in the associated model documentation report (https://doi.org/10.3133/sir20245082).

A new version of previously published steady-state numerical groundwater flow models of the Great Basin carbonate and alluvial aquifer system (GBCAAS), and was developed in conjunction with U.S. Geological Survey (USGS) studies in Parowan, Pine, and Wah Wah Valleys, Utah. This version of the model is considered to be GBCAAS v. 3.0 and supersedes previous versions. This model added 15 transient calibration stress periods and 14 projection stress periods, aquifer storage properties, historical withdrawals in Parowan Valley, and observations of water-level changes in Parowan Valley to the previous steady-state versions. Recharge in Parowan Valley and withdrawal from wells in Parowan Valley and two nearby wells in Cedar City Valley vary for each calibration stress period representing conditions from March 1940 to November 2013. Stresses, including recharge, are the same in each stress period as in the steady-state stress period for all areas outside of Parowan Valley. This data release contains one calibration simulation and one projection simulation. The model is calibrated to transient conditions only in Parowan Valley. Simulated storage properties outside of Parowan Valley are set the same as the Parowan Valley properties and should not be considered calibrated. The projection simulation was used to estimate that reducing withdrawals in Parowan Valley from 35,000 to about 22,000 acre-feet per year should stabilize groundwater levels in the valley if recharge varies as it did from about 1950 to 2012 and that withdrawals of 15,000 acre-feet per year from Pine Valley and 6,500 acre-feet per year from Wah Wah Valley could ultimately (long-term steady-state) cause water-level declines of about 1,900 feet near the withdrawal wells and more than 5 feet over about 10,500 square miles. 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/sir20175072). This data release also contains source code needed to run the models. Model files presented in this data release were modified from an existing, calibrated, steady-state model of the Great Basin carbonate and alluvial aquifer system. SIR 2014-5213 (https://pubs.usgs.gov/sir/2014/5213/) and SIR 2017-5011 (https://doi.org/10.3133/sir20175011) document the construction and calibration of the previous versions of this model. Modifications that were made to the input files and discussion of model results are documented in SIR2017-5072 (https://doi.org/10.3133/sir20175072), which is associated with this data release. The model consists of a parent and a child model and must be run using MODFLOW-LGR. The child model is far removed from the area considered for this project, but is being kept with the model so that one model version exists of the Great Basin carbonate and alluvial aquifer system that incorporates all refinements and improvements. The model files documented in this data release should be used instead of previous versions.