Williamson Act

The California Land Conservation Act, usually referred to as the Williamson Act after the state legislator who introduced the act, is the state's agricultural land protection program.

Intent of the Act

Enacted in 1965, the Williamson Act protects approximately 16 million acres of farm and ranch land across the state. The intent was to preserve agricultural and open space lands by discouraging premature and unnecessary conversion to urban uses. The act creates arrangement whereby private property owners contract with counties or cities to voluntarily restrict land to agricultural and open space uses.

The vehicle for these agreements is a rolling 10 year contract (i.e. unless either party files a notice of non-renewal, the contract is automatically renewed on December 31 for an additional year). In return, contracted parcels of land are assessed for property tax purposes at a rate consistent with their actual use, rather than potential market value.

Tax Savings & Incentives

Having a parcel under contract saves the rural landowner from 20 - 75% in property tax liability each year. In August of 1998, the legislature enhanced the Williamson Act with the farmland security zone (FSZ) provisions. The FSZ provisions offer landowners greater property tax reduction in return for a minimum rolling contract term of 20 years.


In order for a property to be eligible for a Williamson Act contract, the land must be within an agricultural preserve. The boundaries of an agricultural preserve, which can encompass more than one owner's holdings, are defined by a resolution of the Board of Supervisors and determine the areas where the county can enter into Williamson Act contracts with landowners.

As of January 1, 2016, there were a total of 120,635 acres under Williamson Act contracts in Tuolumne County, including 13,734 acres under non-renewal. County rules for participating in the Williamson Act are contained in resolution 106-04.

Associated Fees

New land conservation contracts for the Williamson Act require application fees relating to the contract itself and for the addition of a zone change to add the agricultural preserve combining (AP) district to the primary zoning of the land under the contract.

Applications for new land conservation contracts must have parcels that meet the minimum parcel size for the commercial agricultural use, per rule four of resolution 106-04. For the latest fee information, contact the Community Resources Agency. To assist in the application process, view instructions for submitting an application.

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