Groundwater

To manage the groundwater resource, it is important to know the depth to groundwater. This information can be used to determine the amount of groundwater that can safely be withdrawn. In this way, local water managers can prevent wells from going dry and prevent the movement of poorer quality groundwater into an aquifer.
	DWR's Central District and its cooperators monitor groundwater levels in about 2,000 wells in Central California. Most measurements are made twice a year, once in spring when levels are highest, and once in fall when levels are lowest. Some groundwater levels are monitored monthly.
DWR's Central District maintains an electronic database of groundwater level measurements for part of Central California. The database contains nearly 170,000 individual groundwater level measurements, some dating back to the early 1920s. These data are available in printed reports or electronic form from this Web site.