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Assessor
County Of Sonoma › Administrative Support & Fiscal Services › Clerk-Recorder-Assessor-Registrar of Voters › Assessor › Real Property › Agricultural Real Property Assessments
Assessor

Agricultural Real Property Assessments

Permanent plantings such as vineyards or orchards are assessable as Real Property under Proposition 13 along with any fixture that supports the improvement such as drip, trellis, stakes, etc. Newly planted vineyards will be exempt from taxation for the first 3 years and new orchards will be exempt for 4 years. After the exemption period, the growing improvement will be assessed at market value and increase no more than 2% under Prop 13. Grafting a vine or tree is considered a new planting and will reset the exemption period.  

Planting Records

The Sonoma County Assessor’s Office strives to annually review plantings on vineyard/orchard properties. The online portal file is now closed. Please contact our office at 707-565-1888 or 1-800-244-1034 to discuss your reporting options.

Williamson Act Assessment

Agricultural land and growing assessments on parcels under a Williamson Act contract receive a restricted assessment. A restricted assessment is an annual restricted income approach for Ag land and growing while residences, other structural improvements, land supporting residential uses and growing fixtures are assessed under Prop 13 to create a blended total assessment.  

 Williamson Act Example Valuation

*Please note that this is not a representation of an actual valuation and is only for demonstration purposes.  

Supplemental Assessments for Real Property Fixed Equipment

Starting in the 2025/2026 tax year, the Assessor’s office will be issuing supplemental assessments for changes in fixed equipment that support vineyards and orchards as recommended by the State Board of Equalization. Changes in equipment such as drip, trellis, stakes, etc. will now be captured as a supplemental assessment as of 12/30. These changes will be reported online annually via the Annual Planting Record during the filing period.  Our staff has diligently processed the backlog of unworked Planting Records and notices of change will be going out as we approach the closing of the 2025 tax roll. Please contact our office if you have questions.