DWR Groundwater Elevation Contours 1960 - 2010

This data set contains annual groundwater elevation contours for Spring conditions 1960 through 2010 in the unconfined groundwater aquifer within the San Joaquin Valley portion of the San Joaquin District of the Department of Water Resources. DWR, USBR, and various local water agencies collect groundwater elevations from approximately 3,600 wells during the DWR-defined spring period of each year, generally from January through April. These point data are then plotted and contours hand drawn at 10-foot intervals. In some areas where data points are widely spaced, the contour interval is set to 20, 50 or 100 feet. Some years were digitized from a pdf of the original hardcopy map which was drawn by the Department of Water Resources, Division of Resources Planning. Please note that the area with defined contour intervals varies from year to year and does not necessarily cover the entire valley.