Dear Yolo County Well Drillers and Interested Stakeholders:

I would like to bring your attention to a few updates to the Yolo County Well Ordinance (Ordinance) governing well permit review and issuance:

1. Agricultural (aka: Irrigation Wells) Wells: All agricultural wells will need to meet setbacks specified in Table No.4 of the Ordinance and obtain a YSGA verification letter. Please see Sections 6-8.1004, 6-8.1005, 6-8.1012, and 6-8.1013 for more details. Please note that these requirements have been implemented through Urgency Ordinances and are now being codified to bring more certainty and clarity on the well application process for All agricultural wells.
2. Permit Term: The permit term will be updated from 120 days to 2 years, aligning with current practice under the Urgency Ordinance.
3. Application Term: Adding a time period for which applications are valid. Applications will now be valid for one (1) year, with an option to extend for an additional 180 days. This change is intended to facilitate more timely review and avoid having numerous open and/or incomplete well applications years after permit applications are initially submitted.
4. Appeal Process: Changing the appeal process such that a permit appeal will first go to the Planning Commission to be heard rather than the Board of Supervisors. The Planning Commission's decision can then be appealed to the Board of Supervisors. This change aligns the process with other permitting approvals.
5. Pumping Capacity Verification: Adding a requirement that new agricultural wells must provide a written report to YCEH stating the pumping capacity of the well after the pump is installed and prior to final approval.

The Ordinance can be found via this link: https://codelibrary.amlegal.com/codes/yolocounty/latest/yolo/0-0-0-7714

Looking into the future: More changes to the well permit ordinance will be identified once the Department of Water Resources (DWR) completes its updates to Bulletin 74, which was last updated in 1991. The updated Bulletin 74 will be submitted to the State Water Resources Control Board for adoption into a Statewide Model Ordinance. The County's last communication with DWR indicates that the final standards will be published in Summer 2026. YCEH staff will be working with Luhdorff & Scalmanini Consulting Engineers (LSCE) over the next year to make these recommended changes to the ordinance.

A permit is required for the installation, modification, or abandonment of water wells, test holes, cathodic protection wells, geothermal heat exchange wells, and monitoring wells. Well final inspection is required to give approval to use the well.

Forms used for Well Permit Application: Please visit Forms & Application Page

Well Final Requirements:

• Water Well Requirements for Building Projects 
• Water Sampling Instruction
• Nitrate Acknowledgement Form (Well Owners)

• Free Private Well Testing Program is now available to private well owners in Yolo County. For detail, please see this link.
• Optimized Well Disinfection Procedure
• Basic Well Disinfection Procedures
• Sanitary Well Construction (Illustration)
• Well Defects (Illustration)
• Total Coliform Q&A
• Nitrate Fact Sheet
• Nitrate Fact Sheet in Spanish
• A Guide for Private Domestic Well Owners
• Approved Sealing Materials for Water Well Construction
• Statewide Advisory on Sealing Materials for Wells in California
• DWR Online System for Well Completion Report (OSWCR) Submittal
• Water Well Setback
• DWR Water Well Standards
• Water Well Abandonment

What do I do with an old unused well on my property?

Cover the well with a watertight, bolted-on cover. This will prevent contamination from polluting the ground water and prevent any child from becoming injured from it. A well designated as an abandoned well must be destroyed. 

Can I destroy my own well?

The owner of the well can obtain the permit to destroy or drill a well, but a C-57 State licensed well contractor must do the abandonment.

Who works on wells?

Licensed well contractors with a valid C-57 are qualified to drill and destroy wells. See our Contractors List for a listing of contractors known to do business in Yolo County.

Can you test my drinking water well for agricultural chemicals?

Yolo County Environmental Health Division (YCEH) cannot test for agricultural chemicals or other organic chemicals. Consult an Environmental Health Specialist for chemicals that may be found in the ground water of your area, then contact a state certified drinking water lab for analysis. For a fee, YCEH can test for coliform bacteria and nitrates. Contact us for more information on water testing, or to arrange to have us test your water for Coliform bacteria or nitrates. For information about the Coliform test: what it is, how to get it, what it means, and what to do if the test is positive, see our Coliform Testing Questions and Answers Page.

How long is my well permit good for?

Yolo County Code section 6-8.804 (b) states that well permits expire and become null and void if the work is not commenced within 120 days (4 months) after the date of permit issuance or if the work is suspended or abandoned for a period of 120 days any time after the work is commenced.

Under Yolo County Urgency Ordinance 1569 the well permit term has been temporarily extended to two years from the date of issuance.

Renewal of a permit may be granted for a period of two additional years provided no changes have been made or will be made to the original plans and specification for such work. The fee to renew the permit shall be one half of the current permit fee provided the renewal request is made prior to the expiration of the permit. The permit can be renewed one time.

All well permit renewals are subject to the compliance with the County’s well permitting procedures that may be in effect at the time the renewal is approved.

On March 28, 2022, Governor Newsom issued Executive Order (EO) N-7-22, which was replaced later by Executive Order (EO) N-3-23 on February 13, 2023. This order required additional review and analysis of applications for new groundwater wells. The EO was effective immediately and, among other things, created a new review process for issuance of permits for wells in medium and high priority groundwater basins. Yolo County is a high priority basin.

In response to EO N-7-22 (and EO N-3-23) Yolo County Environmental Health (YCEH) worked with a hydrogeologist from Luhdorff & Scalmanini, Consulting Engineers (LCSE) to develop a Technical Memo (TM), which contained temporary well permitting procedures for agricultural wells.  The YCEH TM was most recently approved by the Board on April 9, 2024.

On September 5, 2024, Governor Newsom issued a new EO N-3-24 that rescinded certain provisions of prior EOs related to the drought, included the well permitting procedures required by EO N-3-23. 

On October 22, 2024, the Yolo County Board of Supervisors adopted an urgency ordinance which temporarily extends the majority of the well permitting procedures which were enacted in compliance with EO N-7-22 and EO N-3-23. 

All new agricultural well permit applications must include a site map and table of all know active wells within a radial distance equal to the minimum separation required for the well, as present in Table 1 below, plus 500 feet.  Click here for a handout that has an example of what is required.

All replacement wells must be accompanied by a well abandonment permit application.

If a permit application is not able to be approved due to the inability to meet the minimum well separation distances, the applicant has the option to submit a report by a professional geologist or hydrogeologist (licensed in the State of California) including associated information concluding that the proposed well will not interfere with the function and operation of nearby wells.

Table 1. Minimum Well Separation Distances

Dear Yolo County Well Drillers and interested stakeholders:

On August 26, 2025, Yolo County Board of Supervisors adopted an Interim Ordinance for a 45-day Moratorium on the approval of new agricultural water well permits in the Focus Areas, including parcels that may be partially included in the Focus Areas (reference to the Focus Areas Map below). The Moratorium will allow the county to conduct study; and develop policies and regulations to implement recommended actions for new agricultural well permits for the Focus Areas. This Moratorium only applies to new and pending well permits applications for the Focus Areas, and shall not apply to well permits already issued by the county.

You are welcome to submit the new well application for the Focus Areas during the Moratorium is in place. However, no permit will be issued until the Moratorium is lifted.

There is a list of wells that are exempt from this Moratorium. This list can be found starting on page 7 of the Ordinance No 1576. The list of exempt wells includes domestic wells producing less than 2 acre-feet per year, public water system wells, and monitoring wells.  

In addition, there is a provision for hardship exemption as prescribed on page 8 of the Ordinance No 1576.

Exempt wells and wells outside the Focus Areas will continue being processed per Urgency Ordinance No. 1569 adopted last year on October 22, 2024.

Dear Yolo County Well Drillers and interested stakeholders:

On October 7, 2025, Yolo County Board of Supervisors approved the extension of a 45-day Moratorium on the approval of new agricultural water well permits in the Focus Areas imposed by the Urgency Ordinance No. 1576 for a period not to exceed an additional 10 months and 15 days. Two changes were made along with the extension. (1): The Moratorium will be narrowed to just new agricultural well permits located within the Focus Area boundaries established by YSGA. (2): Clarify that the hardship exemption may include an economic or health and safety hardship and does not need to meet a higher “taking” threshold.  

You are welcome to submit the new well application for the Focus Areas during the Moratorium is in place. However, no permit will be issued until the Moratorium is lifted.

There is a list of wells that are exempt from this Moratorium. This list can be found starting on page 8 of the Ordinance No 1577. The list of exempt wells includes domestic wells producing less than 2 acre-feet per year, public water system wells, and monitoring wells.  

In addition, there is a provision for hardship exemption as prescribed on page 8 of the Ordinance No 1577.

Exempt wells and wells outside the Focus Areas will continue processed per Urgency Ordinance No. 1569 adopted last year on October 22, 2024.

Focus Areas Map: https://portal.giscloud.com/map/2496272/ysga-draft-focus-areas

Dear Yolo County Well Drillers and interested stakeholders:

On November 4, 2025, the Yolo County Board of Supervisors amended the temporary moratorium on the approval of new agricultural well permits in the YSGA Focus Areas to add an additional exemption for certain replacement wells under the Urgency Ordinance 1580. To be considered a replacement well for purposes of the moratorium exemption, the well will need to meet all of the following conditions:

• The replacement well has the same or smaller casing diameter and substantially similar or deeper casing depth, pump size/pump horsepower, and screen interval(s) to the existing well;
• The replacement well has a substantially similar or lower pumping capacity (gallons per minute or GPM) in comparison to the existing well;
• If records of the construction details, such as well depth and screen intervals are not available for a well being replaced, the applicant should make reasonable efforts to obtain the information through downhole investigative methods including tagging the total completed depth of the well or other methods.
• The existing well being replaced is destroyed or abandoned under permit as set forth in Section 6-8.1011 of the Yolo County Code of Ordinances;
• The replacement well will be located on the same legal parcel(s) irrigated by the existing well being replaced (i.e., the replacement well will be used to irrigate the same farmed area as the well being replaced); and
• The replacement well permit shall include the following conditions: (1) while the moratorium is in effect, prohibiting certain crop conversions, as described below, within the area irrigated by the replacement well on or after the date Ordinance No. 1577 was adopted (October 7, 2025); and (2) requiring the applicant and property owner to comply with any post-issuance conditions that may be imposed to align the permit with requirements included in any ordinance adopted by the Board of Supervisors in connection with the moratorium review process, e.g., potential requirement to install a meter. The procedure for imposing post-issuance conditions shall be included in any such ordinance. For purposes of the prohibition on crop conversions, the intent is to maintain the status quo with respect to groundwater consumption while the moratorium is in place and to protect against changes in classifications of agricultural crops that may increase or harden groundwater demands in the Focus Areas before completion of the studies contemplated in Ordinance No. 1577. Accordingly, the prohibition on crop conversions applies to changes in classifications of crops (dry-farmed, annual, or perennial) cultivated on lands served by the replacement well that would result in planting of a higher water demand type of crop. For instance, converting dry farmed land to irrigated row or perennial crops or converting annual crops (e.g., tomatoes or corn) to perennial crops (e.g., almonds, walnuts, olives, pistachios, and grapes) would be prohibited while the moratorium is in place. However, conversion of a crop to lower water demand crop classification, e.g., conversion from a perennial crop to an annual row crop would be permitted.

To assist staff in the review of permit applications for replacement wells, the attached replacement well in focus areas supplemental questionnaire and acknowledgement must be submitted with replacement well applications IF the well is located within the Focus Areas.

 Urgency Ordinance 1580 can be accessed via this link.

 Focus Areas Map: https://portal.giscloud.com/map/2496272/ysga-draft-focus-areas

Please contact our office at 530-666-8646 or ehealth@yolocounty.gov if you have any questions regarding well permit applications.