There are as many as 2 million water wells in California, with approximately 10,000 to 15,000 new wells constructed each year. They range from hand-dug, shallow wells to carefully designed large-production wells drilled to great depths.


Under the California Water Code Sections 13700 to 13806, we have the responsibility for developing well standards. We maintain these standards to protect groundwater quality. California Well Standards, published as DWR Bulletin 74, represent minimum standards for well construction, alteration, and destruction to protect groundwater. In California, cities, counties, and water agencies have regulatory authority over wells and can adopt local well ordinances that meet or exceed the statewide Well Standards.


When a well is constructed, modified or destroyed, drilling contractor are required to submit a Well Completion Report. Contractors can submit these and the public can access them through our Online System for Well Completion Reports (OSWCR).

The State Water Resources Control Board has authority to adopt DWR well standards into a statewide model well ordinance. Cities, counties, or water agencies have authority to adopt a local ordinance that meets or exceeds DWR well standards. If no local ordinance is adopted, the model well ordinance takes effect in that jurisdiction. Well ordinances are enforced by local enforcing agencies (see the Permitting Agencies tab for more information).


Submit a Well Completion Report

California Water Code Section 13751 requires that anyone who constructs, alters, or destroys a water well, cathodic protection well, groundwater monitoring well, or geothermal heat exchange well must file with the Department of Water Resources a report of completion within 60 days of the completion of the work. Drillers submit their well completion reports with the Online System of Well Completion Reports (OSWCR, say "Oscar"). OSWCR users create an account based on their C-57 license that DWR will validate. Upon approval users will be able to submit Well Completion Reports.

Click here to submit a Well Completion Report

Public Access to Well Completion Reports

California Water Code Section 13752 allows for the release of copies of well completion reports to governmental agencies and to the public. DWR has redacted the personal information from the approximately 800,000 reports on file. They are available online at no charge via a web mapping application here:

Well Completion Report Map Application

If you are unable to find reports of interest using this application, Department staff can process your request, but a fee may be charged as provided by the law. If you are interested in requesting well completion reports instead of using the free online access, please fill out and submit a Well Completion Report Request Form.

In California, regulatory authority over well construction, alteration, and destruction activities rests with local jurisdictions (cities, counties, or water agencies), who have the authority to adopt a local well ordinance that meets or exceeds DWR Well Standards. Permitting and enforcement are carried out by the local enforcing agency (LEA), such as the County Department of Environmental Health. LEAs are listed below alphabetically by county; cities and water agencies are listed under the counties they reside in. Please help us keep this list up to date.


Alameda County

(Eastern Alameda County including Dublin, Pleasanton, Livermore and Sunol Alameda County Flood Control and Water Conservation District)
Zone 7 Water Agency

Alameda County Environmental Health Department

Alameda County Water District

City of Berkeley, Toxics Management Division

Alpine County

Alpine County Health and Human Services, Environmental Health

Amador County
Amador County Environmental Health Department

Butte County
Butte County Public Health

Calaveras County

Calaveras County Environmental Management Agency

City of Anaheim
City of Anaheim Public Works

City of Buena Park
City of Beuna Park Public Works Department

City of Fountain Valley
City of Fountain Valley Public Works Engineering Department

City of Long Beach
City of Long Beach Department of Public Health and Human Services

City of Los Banos
City of Los Banos Public Works Department

City of Orange
City of Orange Public Works Department, Water Division

City of Pasadena
City of Pasadena Water and Power Department

City of Roseville
City of Roseville Environmental Utilities Department

City of San Clemente
City of San Clemente Public Works, Engineering Services

City of Santa Cruz

City of Santa Cruz - Water Department

City of Vernon
City of Vernon Public Works

Colusa County
Colusa County Environmental Health

Contra Costa County
Contra Costa Environmental Health

Del Norte County
Del Norte County Health & Human Services

El Dorado County
El Dorado County Environmental Management

Fresno County (Unincorporated areas)
Department of Public Health Environmental Health Division

Glenn County
Glenn County Environmental Health Department

Humboldt County (except tribal land for well drilling)
Humboldt County  Divison of Environmental Health

Imperial County
Imperial County Planning and Development Services

Inyo County
Inyo County Department of Environmental Health Services

Kern County
Kern County Department of Environmental Health Services

Kings County (Except City of Hanford, City of Lemoore, City of Avenal, and NAS Lemoore)
Community Development Agency

Lake County
Lake County Environmental Health

Lassen County
Lassen County Environmental Health Department

Los Angeles County (all areas in Los Angeles County except for areas within the Cities of Long Beach, Pasadena, and Vernon.)
Department of Health Services

Madera County
Madera County Environmental Health Department

Marin County
Marin County Environmental Health Services

Mariposa County
Mariposa County Environmental Health

Mendocino County (Includes all unincorporated areas of the county)
Division of Environmental Health

Merced County (Except cities of Atwater, Dos Palos, Gustine, Livingston, Los Banos, and Merced, and on any federal or state land.)
Merced County Department of Public Health, Division of Environmental Health

Modoc County
Modoc County Environmental Health Department

Mono County
Mono County Environmental Health Department

Monterey County
Monterey County Health Department, Environmental Health Bureau

Napa County
Napa County Environmental Health Division

Nevada County
Nevada County Environmental Health Department

Orange County (Except Cities of Anaheim, Buena Park, Fountain Valley, Orange, and San Clemente.)
Department of Public Health, Division of Environmental Health

Placer County
Placer County Environmental Health Department

Plumas County (Except City of Portola)
Plumas County Environmental Health

Riverside County
Riverside County Department of Environmental Health

Sacramento County (Includes cities of Sacramento, Folsom, Isleton, Galt, Rancho Cordova, Citrus Heights, and Elk Grove)
Sacramento County Environmental Management Department

San Benito County
San Benito County Water District

San Bernardino County
San Bernadiono County Environmental Health Services

San Diego County
San Diego County Department of Environmental Health

San Joaquin County (Except Stockton, Ripon, and Tracy)
San Joaquin County Environmental Health Department

San Luis Obispo County
San Luis Obispo County Public Health Department, Environmental Health Services Division

San Mateo County
San Mateo County Environmental Health Services Division

Santa Barbara County (Unincorporated)
Santa Barbara County Environmental Health Services

Santa Cruz County
Environmental Health Services of Santa Cruz County

Santa Clara County
Santa Clara Valley Water District

Santa Clara County Environmental Health Department

Shasta County
Shasta County Environmental Health Department

Sierra County Health Department
Sierra County Environmental Health

Siskiyou County
Siskiyou County Environmental Health Department

Solano County
Solano County Environmental Health

Sonoma County
Sonoma County Permit and Resources Management Agency

Monitoring well permits
Environmental Health Division

Stanislaus County (Unincorporated areas)
Stanislaus County Department of Environmental Resources

Sutter County
Sutter County Environmental Health Services

Tehama County
Tehama County Environmental Health Department

Trinity County
Trinity County Environmental Health Department

Tulare County
Tulare County Environmental Health Services Division

Tuolumne County
Tuolumne County Environmental Health

Ventura County (except City of Oxnard)
County of Ventura Watershed Protection District

Yolo County
Yolo County Environmental Health Division

Yuba County
Yuba County Environmental Health

Well Construction

Figure 1. Three well construction methods: dug, driven, and drilled.
Construction of a water well begins with making a hole, using 1 of the 3 methods shown in Figure 1. As the hole is excavated, the licensed well driller logs the depths at which water is produced. This information is used to design the well. Read about each method and view the most common drilling methods at WellOwner.org. 








Figure 2. An example of typical well construction.
Source: State Water Resources Control Board,
March 2015

Figure 2 is an example of typical water well construction.The well "casing" is a metal or plastic pipe that is centered in the hole. The "well screen" is the perforated section of casing next to the aquifer. The remainder of the casing is "blank" with no perforations. Once the casing is inserted, a "filter pack" of sand and/or gravel is placed around the well screen to filter fine soils from water entering the well. The rest of the space between the hole and the blank casing (annular space), is sealed with highly waterproof materials to prevent contaminants from flowing through the space. Finally, the well is completed when the pump is placed and the wellhead features are constructed, including a concrete pad which slopes away from the well.

Protect Your Water Well

Proper design and construction are key to a well's success. The well should be carefully located away from septic systems and other pollutant sources to minimize potential for contamination. The annular space should be sealed with materials that meet statewide minimum well standards and local well ordinance requirements.

Simple preventative measures can ensure your well water stays clean:

Properly Seal Abandoned Wells

Abandoned wells can be pathways for pollutants to enter the groundwater. They also pose a threat to public health and safety –  children, animals, or even adults can fall into abandoned wells, causing injury or death.  Well Decommissioning...There's a Plan for That (video, 3:18 minutes) by the Natural Resources Conservation Service of California provides important information for all landowners to recognize and address abandoned wells with footage from an actual well destruction in Sacramento County in this brief video, Well Decommissioning...There's a Plan for That . If you know  or suspect of an abandoned well, contact your local enforcing agency.

Related Pages


Northern Region
April Scholzen
Water Resources Tech. II
2440 Main Street
Red Bluff, CA 96080
530-529-7368 (office)
530-529-7322 (fax)


North Central Region
Walter Mobley
Water Resources Engineer
Groundwater Supply Assessment & Special Studies Section
3500 Industrial Blvd
West Sacramento, CA 95691
916-376-9610 (office)
916-376-9676 (fax)

South Central Region
Chris Guevara
Water Resources Tech. II
3374 East Shields Avenue
Fresno, CA 93726
559-230-3356 (office)
559-230-3301 (fax)

Southern Region
Michael Van Raalte
Groundwater Section
770 Fairmont Avenue, #102
Glendale, CA 91203
818-549-2307 (office)

DWR Headquarters

Well Completion Reports/OSWCR

Ben Brezing
Engineering Geologist
901 P Street
P.O. Box 942836
Sacramento, CA 94236

Eric Senter
Senior Engineering Geologist
901 P Street
P.O. Box 942836
Sacramento, CA 94236