This digital data set contains the locations, water-level altitude, and water-level differences of 70 wells selected to document water-level changes between fall 2004 and spring 2005 in the Anza-Terwilliger area of Riverside County, California. The winter of 2005 was one of the wettest periods on record. Links to the U.S. Geological Survey National Water Information Systems Website (NWISWeb) have been established to interactively view recent water-level information via the internet by clicking on a specific well.

The U.S. Geological Survey (USGS) entered into a cooperative study with the California Department of Water Resources and the Ramona Band of Cahuilla to characterize the hydrogeology of the Cahuilla Valley and Terwilliger Valley groundwater basins and surrounding water-bearing units, with the ultimate goal of developing a calibrated integrated hydrologic model to manage the groundwater supplies on a sustainable basis. A three-dimensional geologic framework model (GFM) was developed to quantify the structural geometry and distribution of water-bearing units in the groundwater basins, using borehole lithology and hydraulic information, geologic maps, and gravity-derived depth-to-basement information. This dataset includes (1) tabular data of selected boreholes with their location and construction information, (2) borehole lithology information, (3) a geographic information systems (GIS) shapefile of a cellular array containing interpolated elevations and thicknesses of modeled geologic units from the GFM in the format of a polygon feature class, (4) and a table of summary textural classes for the alluvial fill unit from borehole logs and summary textural classes used in geologic framework model.

The U.S. Geological Survey (USGS) entered into a cooperative study with the California Department of Water Resources and the Ramona Band of Cahuilla to characterize the hydrogeology of the Cahuilla Valley and Terwilliger Valley groundwater basins and surrounding water-bearing units, with the ultimate goal of developing a calibrated integrated hydrologic model to manage the groundwater supplies on a sustainable basis. A three-dimensional geologic framework model (GFM) was developed to quantify the structural geometry and distribution of water-bearing units in the groundwater basins, using borehole lithology and hydraulic information, geologic maps, and gravity-derived depth-to-basement information. This dataset includes (1) tabular data of selected boreholes with their location and construction information, (2) borehole lithology information, (3) a geographic information systems (GIS) shapefile of a cellular array containing interpolated elevations and thicknesses of modeled geologic units from the GFM in the format of a polygon feature class, (4) and a table of summary textural classes for the alluvial fill unit from borehole logs and summary textural classes used in geologic framework model.

This report provides a full digitization of historic groundwater-quality and depth-to-water data from Mendenhall and others (1916) Water Supply Paper 398, “Ground Water in San Joaquin Valley, California” in a modern format suitable for further analysis of California’s water supply resources. Included are geochemical data for over 400 wells collected by Mendenhall in the fall of 1910, as well as depth-to-water and well construction information from over 4000 wells compiled by his team from over 15 years of well surveys throughout the San Joaquin Valley. Additionally, these data provide geospatial and geochemical data for sampled wells in California's San Joaquin Valley (SJV) in support of the publication: Hansen, J.A., Jurgens, B.C, Fram, M.S., Quantifying Anthropogenic Contributions to Century-Scale Groundwater Salinity Changes, San Joaquin Valley, California, USA, Science of the Total Environment, vol. XX, no. X, pp. XX-XX, 2018.

This report provides a full digitization of historic groundwater-quality and depth-to-water data from Mendenhall and others (1916) Water Supply Paper 398, “Ground Water in San Joaquin Valley, California” in a modern format suitable for further analysis of California’s water supply resources. Included are geochemical data for over 400 wells collected by Mendenhall in the fall of 1910, as well as depth-to-water and well construction information from over 4000 wells compiled by his team from over 15 years of well surveys throughout the San Joaquin Valley. Additionally, these data provide geospatial and geochemical data for sampled wells in California's San Joaquin Valley (SJV) in support of the publication: Hansen, J.A., Jurgens, B.C, Fram, M.S., Quantifying Anthropogenic Contributions to Century-Scale Groundwater Salinity Changes, San Joaquin Valley, California, USA, Science of the Total Environment, vol. XX, no. X, pp. XX-XX, 2018.

Groundwater-quality data collected between 1993 and 2015 were compiled from the U.S. Geological Survey (USGS) National Water Information System (NWIS) database for 722 wells in the San Joaquin Valley (SJV). Groundwater-quality data retrieved included lab analyses of complete major ion data (calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate, alkalinity, bicarbonate, carbonate, silica, and TDS) for 613 samples, and an additional 109 samples with measured values of specific conductance. Most of these wells were sampled as part of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project or the USGS National Water Quality Assessment (NAWQA) Program. In addition to GW quality data, the dataset includes well depths, measured or interpolated water levels, summary land-use information, and a tritium-based groundwater age classification. Each well was assigned to a geospatial grid cell in one of six SJV regions (https://www.sciencebase.gov/catalog/item/5892423ee4b072a7ac145e06). These data support the following publication: Hansen, J.A., Jurgens, B.C, Fram, M.S., Quantifying Anthropogenic Contributions to Century-Scale Groundwater Salinity Changes, San Joaquin Valley, California, USA: Science of the Total Environment, vol. XX, no. X, pp. XX-XX, 2018.

Groundwater-quality data collected between 1993 and 2015 were compiled from the U.S. Geological Survey (USGS) National Water Information System (NWIS) database for 722 wells in the San Joaquin Valley (SJV). Groundwater-quality data retrieved included lab analyses of complete major ion data (calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate, alkalinity, bicarbonate, carbonate, silica, and TDS) for 613 samples, and an additional 109 samples with measured values of specific conductance. Most of these wells were sampled as part of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project or the USGS National Water Quality Assessment (NAWQA) Program. In addition to GW quality data, the dataset includes well depths, measured or interpolated water levels, summary land-use information, and a tritium-based groundwater age classification. Each well was assigned to a geospatial grid cell in one of six SJV regions (https://www.sciencebase.gov/catalog/item/5892423ee4b072a7ac145e06). These data support the following publication: Hansen, J.A., Jurgens, B.C, Fram, M.S., Quantifying Anthropogenic Contributions to Century-Scale Groundwater Salinity Changes, San Joaquin Valley, California, USA: Science of the Total Environment, vol. XX, no. X, pp. XX-XX, 2018.

Well construction data for 11,917 domestic and 2,390 public-supply wells in the Central Valley were compiled as part of the U.S. Geological Survey (USGS) National Water Quality Assessment Project (NAWQA) and California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP). Data were compiled for wells reported in the USGS National Water Information System (NWIS) database and from well information reported to the SWRCB Department of Drinking Water (SWRCB-DDW). Driller’s log data were transcribed from scanned images of well completion reports filed with California Department of Water Resources (DWR). The wells reported in this data release were filtered by water use to select domestic and public-supply wells and omit other water uses. The compilation was then assumed to be representative of the total population of domestic and public-supply wells in the Central Valley. The wells in the compilation were constructed between 1911 and 2008 but are not grouped or separated by date. The data were used to produce two point data sets containing well location and construction information (depth from land surface to the top and bottom of the well screen, hereafter well-screen tops and bottoms; and screen length), and 12 interpolated GIS raster surfaces created by using Empirical Bayesian Kriging on a 1600 by 1600 meter (1 square-mile) grid. The tables are also included in csv format. The 12 rasters comprise predicted values for well screen tops and bottoms and their 10th and 90th quantile values. The interpolated surfaces may also be used to calculate volumes of water-supply in the Central Valley defined by the well-screen tops and bottoms.

Well construction data for 11,917 domestic and 2,390 public-supply wells in the Central Valley were compiled as part of the U.S. Geological Survey (USGS) National Water Quality Assessment Project (NAWQA) and California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP). Data were compiled for wells reported in the USGS National Water Information System (NWIS) database and from well information reported to the SWRCB Department of Drinking Water (SWRCB-DDW). Driller’s log data were transcribed from scanned images of well completion reports filed with California Department of Water Resources (DWR). The wells reported in this data release were filtered by water use to select domestic and public-supply wells and omit other water uses. The compilation was then assumed to be representative of the total population of domestic and public-supply wells in the Central Valley. The wells in the compilation were constructed between 1911 and 2008 but are not grouped or separated by date. The data were used to produce two point data sets containing well location and construction information (depth from land surface to the top and bottom of the well screen, hereafter well-screen tops and bottoms; and screen length), and 12 interpolated GIS raster surfaces created by using Empirical Bayesian Kriging on a 1600 by 1600 meter (1 square-mile) grid. The tables are also included in csv format. The 12 rasters comprise predicted values for well screen tops and bottoms and their 10th and 90th quantile values. The interpolated surfaces may also be used to calculate volumes of water-supply in the Central Valley defined by the well-screen tops and bottoms.

This digital geospatial dataset documents the fault traces in the Anza and Terwilliger area of southwest Riverside County, California, that were modified from Moyle (1971) by Woolfenden and Bright (1988, figure 8). The fault information is used to help assess ground-water level changes in the area of Anza and Terwilliger between 2004 and 2005.