DATE: November 17, 2026
TO: Board of Supervisors
SUBMITTED BY: Supervisor Buddy Mendes, District 4
Paul Dictos, CPA, Assessor-Recorder
SUBJECT: Adopt Resolution Electing to Assess Williamson Act Contract Lands Under State Revenue and Taxation Code Section 423.3
RECOMMENDED ACTION(S):
TITLE
1. Adopt Resolution electing for the County to assess land under Williamson Act contracts pursuant to State Revenue and Taxation Code section 423.3, allowing contracted land to be assessed at the value determined under section 423, but not to exceed ninety percent (90%) of factored base-year value; and
2. Designate the County Assessor-Recorder as the County officer authorized to request the demonstration of eligibility pursuant to State Revenue and Taxation Code section 423.3(b).
REPORT
There is no increase to Net County Cost associated with the recommended actions for FY 2026-27; however, the proposed assessment methodology is estimated to reduce property tax revenues by approximately $1 million to $2 million annually, of which approximately 13 percent ($130,000 to $260,000) would impact the County’s General Fund. This item requests your Board adopt a Resolution authorizing the County to use optional assessment provisions under State Revenue and Taxation Code section 423.3 for Williamson Act contracted lands. This action may provide additional property tax relief to qualifying contracted parcels by applying capped percentages to factored base-year values, consistent with State law. The Resolution sets the applicable maximum percentage limits and designates the Assessor-Recorder to request the showing required of prime commercial rangeland under section 423.3(b). This item is countywide.
ALTERNATIVE ACTION(S):
If your Board does not approve the recommended actions, properties under Williamson Act contracts that currently receive little or no tax benefit will continue to be assessed under existing rules, and the County will not implement the optional method intended to improve tax equity and achieve the statutory purposes of the Williamson Act.
FISCAL IMPACT:
There is no increase in Net County Cost associated with the recommended actions for FY 2026-27. Based on the 90 percent cap (10 percent valuation reduction), adoption of the Resolution is estimated to result in an annual reduction of approximately $1 million to $2 million in property tax revenues across all affected taxing entities, beginning in FY 2027-28. Based on the County’s estimated 13 percent share of property tax revenues, the corresponding reduction in County revenues is estimated at approximately $130,000 to $260,000 annually.
DISCUSSION:
The Williamson Act, formally known as the California Land Conservation Act of 1965, allows counties to enter into contracts with landowners to preserve agricultural and open-space land. In exchange for agreeing to maintain their land in agricultural use for at least ten years, participating landowners receive reduced property-tax assessments based on the land’s agricultural income rather than its market value. The Act is intended to support agricultural viability, prevent premature conversion of farmland, and promote long-term land conservation.
Revenue and Taxation Code section 423.3 allows a county to cap the assessed value of Williamson Act land at a uniformly applied percentage of its factored base-year value. The statute sets a minimum percentage for each category: 70 percent for prime agricultural land; 80 percent for prime commercial rangeland; 90 percent for other land devoted to open-space uses of statewide significance; and 90 percent for migratory waterfowl habitat. A county may choose any percentage at or above these minimums. The first three categories apply to Williamson Act land; the fourth applies only to land under migratory waterfowl habitat contracts and is not affected by this action. The proposed Resolution applies a single 90 percent cap, a 10 percent reduction, to all three Williamson Act categories.
Because some Williamson Act contracted properties have factored base-year values established under Proposition 13 that are lower than their restricted values calculated pursuant to Revenue and Taxation Code Section 423, these properties may receive little or no additional assessment benefit from their Williamson Act contracts. The optional assessment methodology under Section 423.3 may provide additional assessment reductions for qualifying contracted lands.
The proposed Resolution addresses this issue by:
• Electing the optional valuation method in section 423.3;
• Capping assessed value at 90 percent of factored base-year value (a 10 percent reduction) for all land types;
• Providing additional property tax relief to qualifying contracted parcels, where applicable; and
• Designating the Assessor-Recorder to request eligibility documentation when needed.
The Resolution applies to all existing and future Williamson Act contracts in the County.
ATTACHMENTS INCLUDED AND/OR ON FILE:
On file with Clerk - Resolution
CAO ANALYST:
Mary Lu Valencia