Inverse Model Data for: Salinity trends in a groundwater system supplemented by 50 years of imported Colorado River water

Data provided here describe the contribution of up to 7 different water sources to the major ion geochemistry of U.S. Geological Survey (USGS) and California State Water Resources Control Board Division of Drinking Water (CA-DDW) groundwater samples within the Indio Subbasin of the Coachella Valley, California. The Inverse Geochemical Modeling was performed in the USGS's PHREEQC ver. 3 program and the results are discussed in the associated publication of Harkness and others (2023). Datasets include the major ion chemistry and model input parameters of 1593 samples included in the analysis, the median model results for each sample, and a data dictionary describing the tables. Analyses completed as part of this assessment relied on the previously published data of Harkness (2022) and no new data were collected.