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Well Permit Verification

Under Executive Orders N-7-22 and N-3-23, the YSGA must review all new well permits while California's drought emergency is in effect. This review does not apply to domestic wells extracting less than 2 acre-feet per year, or wells used for public water systems.

Yolo County Division of Environmental Health (DEH) is the permitting agency for groundwater wells, and applications should be submitted to DEH as normal. Yolo County Environmental Health Water Well Program

In order for DEH to issue a well permit, the YSGA must send written verification that groundwater extraction by the proposed well:

  • would not be inconsistent with any sustainable groundwater management program established in the Yolo Subbasin Groundwater Sustainability Plan AND
  •  would not decrease the likelihood of achieving a sustainability goal for the Yolo Subbasin.

YSGA Permit Review Procedures

To provide this verification, YSGA has updated procedures and criteria for use in reviewing well permits. Below is a flowchart outlining the process.

focus areas

The Focus Areas are areas in the Yolo Subbasin in which well permit applicants that are not exempt from the Executive Orders will be required to submit additional information for the YSGA to review.  Well permits submitted within a Focus Area will go through the Tiered Review Process described below. 

The Focus Areas map was prepared using various hydrologic data, reported citizen concerns, and professional judgement to delineate areas in the Yolo Subbasin that may be sensitive to groundwater pumping and warrant additional information and analysis. 

Interact with the Focus Areas map below, or Click here for the full version

tiered review process

This process applies to well permit applications inside the Focus Areas only

Tier 1 – YSGA completes a hydrogeologic evaluation and impact assessment of the well design and details provided by the well applicant in the Tier 1 Analysis Form.  This will include extracting aquifer properties from the YSGA’s Groundwater Model unique to the location and depth of the proposed well, and an assessment of groundwater level impacts using analytical methods.

  • If there are no sustainability concerns identified in respect to impacts on groundwater levels at nearby monitoring wells, water quality, interconnected surface waters, and land subsidence, then the YSGA will provide Yolo County Division of Environmental Health with written verification for the well permit application.
  • If there are sustainability concerns identified by any of the above indicators, then the YSGA will request that the applicant advance to Tier 2 and complete a Hydrogeology Report.

 Tier 2 – YSGA will request the applicant focus the Hydrogeology Report on the sustainability indicators of concern and relate the analysis to the Yolo Subbasin GSP sustainable management criteria and minimum thresholds.  Additionally, a Professional Geologist or Certified Hydrogeologist will certify that the proposed well complies with the Executive Order. 

  • If the prepared report provides evidence that alleviates the concerns around groundwater levels, water quality, and/or subsidence that arose in Tier 1, the YSGA will issue written verification of the well application.
  • If one or more indicators remain a concern to the YSGA, the YSGA will document these concerns and request a meeting with the well applicant to discuss options to bring the well into compliance with the EO.

The Full Technical Memo outlines the requirements and components of YSGA permit review within the Focus Areas. 

Resources and Documents

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