Compilation of the salient characteristics of numerical groundwater-flow and solute- and heat-transport models published or developed by the U.S. Geological Survey for regions in the U.S. and its territories and commonwealths, 1970 through 2022 (ver. 2.0, March 2025)

The U.S. Geological Survey (USGS) National Extent Hydrogeologic Framework for National Water Census (NEHF) project is a multi-year effort (2022 through 2025) that will compile existing assets (approaches, data, software, etc.), develop a strategic plan, and implement an operational framework that is dynamic and multi-scale. Within the USGS, numerical groundwater-flow and solute- and heat-transport models have been created for a variety of purposes that include water-resource assessments, contaminant-transport evaluations, and water-management planning. These models are often supported by hydrogeologic-framework studies that describe the surface and subsurface distribution of geologic materials and their hydrologic properties. This digital data release was developed as part of the NEHF project to compile, in tabular and spatial form, information on the salient characteristics of numerical groundwater-flow and solute- and heat-transport models published or developed by the USGS for regions in the U.S. and its territories and commonwealths from the date of the earliest published model, 1970, through 2022. Version 2.0 of this data release adds spatial information on the structural and hydrologic properties of a subset of the models.

This data release includes six files:
GroundwaterFlowModelsMetadata.xml is the metadata describing the purpose, creation, and other files included in the data release.
GroundwaterFlowModelsWSC.csv is a tabular comma-separated-values file that compiles information on the salient characteristics of the models included in this data release.
GroundwaterFlowModelsOnline.csv is a tabular comma-separated-values file that compiles information on additional salient characteristics of a subset of the models included in this data release. This subset of models consists of those that have model files available online and have an approximate plan-view extent of active model area greater than 10,000 square kilometers.
GroundwaterFlowModelExtents.zip is a zip file containing a shapefile of the inactive and active areas, or active area, of the models as polygon features. 63 models were not represented with a polygon feature because of a lack of spatial information or because the models were one-dimensional or two-dimensional cross sections with a minimal plan view areal extent.
GroundwaterFlowModelGrids.zip is a zip file containing shapefiles of model grids with the structural (layer elevations, active/inactive grid cells, and initial water levels) and hydrologic (hydraulic conductivity and storage) properties. 241 models were included for which digital model files were available and able to be read and processed by FloPy.
version_history.txt is a text file that describes the changes that have been made and includes instructions on how to access previous versions.