In any given year, whether it’s a wet winter or a dry one, groundwater is a critical source of water for California, providing 40 percent to 60 percent of the state’s supply. Some areas of the state are entirely dependent on groundwater. 

To help you learn more about the importance of groundwater, the Water Education Foundation has an array of educational materials on this vital resource. And next week, the Foundation’s flagship publication, Western Water news, will publish a special report examining how two local groundwater agencies are taking different approaches to achieve sustainability in the San Joaquin Valley, one of the most critically overdrafted regions in the state. You can sign up here to be alerted when this special report is published. 

Among the resources now in our library is a California Groundwater Map, which illustrates the value and use of groundwater in California, the main types of aquifers and the connection between groundwater and surface water.

Our Layperson’s Guide to Groundwater explores management challenges – such as overdraft, land subsidence and seawater intrusion – and the laws governing the use of groundwater. The guide includes a section devoted to the Sustainable Groundwater Management Act (SGMA), which requires areas throughout the state to establish local agencies to manage groundwater and ensure its sustainable use beginning in 2040 for the most critically overdrafted basins.  Our Groundwater Education Bundle allows you to purchase both the map and the Layperson’s Guide at a discount.

In addition, Aquapedia – our free online water encyclopedia – has numerous entries explaining different facets of groundwater in California.