Well Inventory Database
The Well Inventory Database (WIDB) is undergoing upgrades and maintenance. During this time, the 2022 update of the WIDB is provided separately and includes only data for wells sampled in 2021. The historical dataset continues to be available on this page.
The datasets currently available as comma-separated values (CSV) files are:
- Data in an alternate format for sampling dates from January 1, 2021 through December 31, 2021.
- Historical dataset in standard format for sampling dates from August 1977 through December 31, 2020.
DPR maintains the WIDB of wells sampled for pesticides by DPR and other agencies. To make water quality data more accessible, a copy of the database is available online. This database copy includes information about the well, the study name, the sampling agency, sample date, analysis date, analyzing laboratory, chemical analyzed, concentration reported, reporting limit, legal agricultural use determination (point or non-point source determination), and the year the record was included in the database. Testing done for other water parameters (i.e., pH, salt, calcium) is not included in the database. There are over two million records in the database.
WIDB in CSV file format for 2021 sampling dates
This dataset is in an alternate format for sampling dates from January 1, 2021 through December 31, 2021. This dataset does not include the exact well location for any wells sampled by DPR; instead, the latitude and longitude data provided for DPR-sampled wells are the centroid of their respective public lands survey system section. Data acquired from other agencies through California Safe Drinking Water Information System and the Water Quality Portal contain publicly available latitude and longitude, and are included in this dataset. Additionally, all wells/samples, regardless of sampling agency, are identified by county, the county-meridian-township-range and section (COMTRS), and the unique well key assigned to all wells in the WIDB.
- Complete Statewide File, CSV, January 1, 2021 to December 31, 2021
- Data Dictionary, CSV, for January 1, 2021 to December 31, 2021 dataset
WIDB in CSV file format for sampling dates from 1977 through 2020
The following links are for the WIDB historical dataset containing over two million records. The data are provided in standard format for sampling dates from August 1977 through December 31, 2020. The complete statewide CSV file is available; however, it cannot be opened in Excel because the file exceeds Excel’s row limit. The data are also available separately by county in CSV file format and these smaller files can be opened in Excel.
This dataset does not include the exact well location or the well owner’s name and address. The WIDB data and well locations are listed by county, the county-meridian-township-range and section (COMTRS), the unique well key assigned to all wells in the WIDB, and a randomized latitude and longitude based on the CMTRS of the well.
- Complete Statewide File, CSV, August 1977 to December 31, 2020 (File exceeds Excel row limit)
- Data Dictionary, CSV, for August 1977 to December 31, 2020 dataset
CSV files separated by county for August 1977 to December 31, 2020:
Note about excluded data
Some records in the database are questionable and were excluded due to the following:
- Point Source Contamination due to pesticide spills near the wellhead, missing backflow protection devices, poor well construction, or monitoring wells surrounding pesticide application test-plot fields.
- Probable Laboratory/Sampling Agency reporting errors where DPR was unable to confirm or deny the validity of data submitted from outside agencies.
This affected 989 reported detections and the excluded data are available on request.
For content questions, contact:
GWPP@cdpr.ca.gov