Locations of Ground Water Protection Areas

Back to Identifying and Protecting Ground Water Protection Areas

DPR defines a Ground Water Protection Area (GWPA) as an area of land that is vulnerable to the movement of pesticides to groundwater by either leaching or runoff processes. DPR established one-square-mile sections of land as GWPAs if any of the following are true:

  • previous detections of specific pesticides in that section
  • contains coarse soils and depth to groundwater < 70 feet
  • contains runoff-prone soils/hardpans and depth to groundwater < 70 feet

DPR restricts the use of specific pesticides in GWPAs, and the regulations and management practices differ depending on whether the GWPA is vulnerable to leaching or runoff. For more information on GWPA regulations and guidance, see pesticide use regulations to protect groundwater.

The table below provides lists of sections and maps for counties that have GWPAs. Counties not listed have no GWPAs. Counties marked with * have new GWPAs effective January 1, 2020.

Butte * Colusa * Contra Costa * Fresno *
Glenn * Kern * Kings * Los Angeles *
Madera * Mendocino Merced * Modoc
Monterey * Orange Placer Riverside
Sacramento San Bernardino San Joaquin * San Luis Obispo
Shasta Siskiyou Solano * Sonoma
Stanislaus * Sutter Tehama Tulare *
Ventura Yolo Yuba  

The Interactive California Pesticide Information Portal (CalPIP) is available to locate GWPAs.

The GWPA boundaries are based on the Public Lands Survey System. The following links provide a map of the statewide Public Lands Survey System used by DPR and downloadable GIS shapefiles of the townships and sections.


For content questions, contact:
GWPP@cdpr.ca.gov