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 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 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).

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.

U.S. Geological Survey (USGS) in cooperation with the U.S. Air Force Civil Engineering Center conducted short-term aquifer tests at 11 wells to estimate hydraulic properties in the Fountain Creek alluvial aquifer, in El Paso County, Colorado. Data were collected in July 2019 over three days. Single-hole pumping and recovery tests were completed at five wells, and multiple single-hole displacement (solid slug) tests were conducted at all 11 wells. This data release contains water-level data collected at various time intervals (0.25 seconds, 0.5 seconds, and variable during a manual test with a stopwatch) and well-discharge rates for the aquifer tests in comma separated value (CSV) files for the 34 tests analyzed. All water-level displacement data for a given well are provided in a single CSV file for the well. Data are further categorized by the type of aquifer test used for data collection (slug or pumping). Well logs, graphs of the test data, and plots of analytical solutions are included in file, “FCAA_aquifer_testing_description_plots_vFINAL.pdf.”

U.S. Geological Survey (USGS) in cooperation with the U.S. Air Force Civil Engineering Center conducted short-term aquifer tests at 11 wells to estimate hydraulic properties in the Fountain Creek alluvial aquifer, in El Paso County, Colorado. Data were collected in July 2019 over three days. Single-hole pumping and recovery tests were completed at five wells, and multiple single-hole displacement (solid slug) tests were conducted at all 11 wells. This data release contains water-level data collected at various time intervals (0.25 seconds, 0.5 seconds, and variable during a manual test with a stopwatch) and well-discharge rates for the aquifer tests in comma separated value (CSV) files for the 34 tests analyzed. All water-level displacement data for a given well are provided in a single CSV file for the well. Data are further categorized by the type of aquifer test used for data collection (slug or pumping). Well logs, graphs of the test data, and plots of analytical solutions are included in file, “FCAA_aquifer_testing_description_plots_vFINAL.pdf.”

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.

A three-dimensional groundwater flow model (MODFLOW2000) of the Denver Basin bedrock aquifer system and overlying alluvial aquifer was developed to provide quantitative estimates of groundwater flow conditions and provide a useful tool for managers to analyze temporal changes to the hydrologic system in response to changing climatic conditions and future groundwater development. In 2004, the U.S. Geological Survey (USGS) initiated large-scale regional studies to provide updated assessments of groundwater availability in important principal aquifers across the United States, including the Denver Basin. The Denver Basin groundwater flow model includes several enhancements over previous modeling efforts because of the availability of additional data, improved modeling capabilities, and advanced computer technology. Additional data available include updated geologic mapping, additional geophysical logs, water-level, streamflow, precipitation, and irrigation data collected since previous studies; and updated estimates of pumping from Denver Basin bedrock and alluvial aquifers. Modeling capabilities and computer technology also have advanced such that additional features, hydrologic processes, and numerical techniques are included in the current model that were not possible in previous models. The Denver Basin groundwater flow model represents regional time-varying (transient) conditions prior to 1880 through 2003. The model was calibrated by primarily adjusting hydraulic conductivity and recharge parameters until a best fit was obtained between observed and simulated transient hydraulic heads and flows using PEST. The calibrated model was used to estimate the hydrologic system response to two pumping scenarios for the period 2004 through 2053. This USGS data release contains all of the input and output files for the simulation and calibration described in the associated model documentation report (https://pubs.er.usgs.gov/publication/pp1770).