Since the Fall of 1971, the San Joaquin County Flood Control and Water Conservation District (District) has monitored groundwater levels and groundwater quality throughout San Joaquin County and has published the data in the Semi-annual Groundwater Report. This report utilizes data from Federal, State and local government agencies as well as non-governmental sources.
Water level data is collected on a semi-annual basis, during the months of April and October, to observe groundwater levels before and after peak groundwater pumping conditions. Over 550 wells, of which 300 are measured by County staff, are included in the Monitoring Program. The exact number of wells varies from year to year, depending on circumstances such as destructions, new well construction, well accessibility, and well condition.
To view any of the Districts Groundwater reports, please click on the reporting period of you choice below.
You may also access the County's historic groundwater data through the San Joaquin County Groundwater Data Center (GDC). The GDC is a Countywide centralized groundwater information vehicle that provides access to groundwater data collected and shared by agencies throughout San Joaquin County.
To enter the GDC please read the following disclaimer:
By using this application you acknowledge and accept the following terms and conditions. The information on this map is based on the most current information available to the San Joaquin County Flood Control and Water Conservation District. The County of San Joaquin does not warrant its accuracy or suitability for any particular purpose. The information on this map is not intended to replace engineering, financial or primary records research.