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Land Conservation (Williamson) Act

Questions & Answers

The California Land Conservation Act, better known as the Williamson Act, has been the state’s premier agricultural land protection program since its enactment in 1965. More than 16 million of the state’s 30 million acres of farm and ranch land are currently protected under the Williamson Act.
  • What is the California Land Conservation (Williamson) Act?

  • What benefits do Williamson Act contracts offer to landowners?

  • What is an agricultural preserve?

  • How many acres are required for an agricultural preserve?

  • What is a Williamson Act Contract?

  • How does a landowner initiate a Williamson Act Contract?

  • How long must land be maintained under a Williamson Act contract?

  • What is the nonrenewal process?

  • What is a cancellation?

  • Must a landowner comply with the terms and conditions of a contract?

  • What happens to a Williamson Act contract upon sale of the property?

  • What are the land uses permitted within an agricultural preserve and contracted land?

  • What happens if an owner fails to comply with the terms and conditions of a contract?

  • Does my county participate?

    What is the State’s role?


      What is the California Land Conservation (Williamson) Act?

      The California Legislature passed the Williamson Act in 1965 to preserve agricultural and open space lands by discouraging premature and unnecessary conversion to urban uses. The Act creates an arrangement whereby private landowners contract with counties and cities to voluntarily restrict their land to agricultural and compatible open-space uses. The vehicle for these agreements is a rolling term 10-year contract (i.e., unless either party files a "notice of nonrenewal," the contract is automatically renewed for an additional year.). In return, restricted parcels are assessed for property tax purposes at a rate consistent with their actual use, rather then potential market value.  Please see the Williamson Act Overview page for more historic information about the Program. 

      Contract provision basics are contained in Government Code Section 51243.

      What Benefits do Williamson Act Contracts Offer to Landowners?



      The Williamson Act is estimated to save agricultural landowners from 20 percent to 75 percent in property tax liability each year. Many counties offer a Williamson Act calculator to determine the value of a contract. 

      A recent survey found that as of 2009, 71% of Williamson Act–enrolled ranchers reported a net annual profit equal to or less than their Williamson Act property tax savings.  Williamson Act tax reductions made the difference between profit and loss for the majority of California ranchers in the Central Valley and surrounding foothills (California Agriculture, Fall 2012).

      Prior studies found that one in three Williamson Act farmers and ranchers said that without the Act they would no longer own their parcel (Land in the Balance, University of California: December 1989).

      What is an Agricultural Preserve?

      An agricultural preserve defines the boundary of an area within which a city or county will enter into contracts with landowners. The boundary is designated by resolution of the board of supervisors (board) or city council (council) having jurisdiction. Only land located within an agricultural preserve is eligible for a Williamson Act contract. Preserves are regulated by rules and restrictions designated in the resolution to ensure that the land within the preserve is maintained for agricultural or open space use.

      How Many Acres Are Required for an Agricultural Preserve?

      An agricultural preserve must consist of no less than 100 acres. However, in order to meet this requirement two or more parcels may be combined if they are contiguous, or if they are in common ownership. Smaller agricultural preserves may be established if a board or council determines that the unique characteristic of the agricultural enterprise in the area calls for smaller agricultural units, and if the establishment of the preserve is consistent with the General Plan. Preserves may be made up of land in one or more ownerships.

      What is a Williamson Act Contract?

      A Williamson Act Contract is the legal document that obligates the property owner, and any successors of interest, to the contract's enforceable restrictions.

      How Does a Landowner Initiate a Williamson Act Contract?

      A landowner interested in enrolling land in a contract should contact the local planning department of the county in which the land is located to obtain information and instructions.

      How Long Must Land be Maintained Under a Williamson Act Contract?

      The minimum term for a contract is 10 years.  However, some jurisdictions exercise the option of making the term longer, up to twenty years.  Contracts renew automatically every year unless the nonrenewal process is initiated.  In 2011, in response to the elimination of the Open Space Subvention funds, Assembly Bill (AB) 1265 was approved allowing eligible counties to re-capture 10 percent of the property tax benefits by implementing reduced term contracts (see AB 1265 Advisory Statement for additional information).  Implementing these provisions is at the discretion of the individual county; therefore, you should contact your county in order to determine if reduced term contracts have been implemented. 

      What is the Nonrenewal Process?

      Either the local government, or landowner, can initiate the nonrenewal process. A "notice of nonrenewal" starts the 9-year nonrenewal period. During the nonrenewal process, the annual tax assessment gradually increases. At the end of the 9-year nonrenewal period, the contract is terminated.

      What is a Cancellation?

      Only the landowner can petition to cancel a contract. To approve a tentative contract cancellation, a county or city must make specific findings that are supported by substantial evidence. The existence of an opportunity for another use of the property is not sufficient reason for cancellation. In addition, the uneconomic character of an existing agricultural use shall not, by itself, be a sufficient reason to cancel a contract. The landowner must pay a cancellation fee equal to 12 1/2 percent of the cancellation valuation of the property.  More details on the cancellation process are outlined on this page.

      Must a Landowner Comply with the Terms and Conditions of a Contract?

      Yes. A Williamson Act contract secures an enforceable restriction. Failure to meet the conditions of the contract may be considered a breach of the contract. 

      What Happens to a Williamson Act Contract Upon Sale of the Property?


      A Williamson Act contract runs with the land and is binding on all successors in interest of the landowner.

      What are the Land Uses Permitted within an Agricultural Preserve and Contracted Land?

      The Williamson Act states that a board or council by resolution shall adopt rules governing the administration of agricultural preserves. The rules of each agricultural preserve specify the uses allowed. Generally, any commercial agricultural use will be permitted within any agricultural preserve. In addition, local governments may identify compatible uses permitted with a use permit.

      What Happens if an Owner Fails to Comply with the Terms and Conditions of a Contract?

      In the case of a breach of a contract, the local government may seek a court injunction to enforce the terms of the contract. Structures permitted or built after January 1, 2004, exceeding 2,500 square feet that are not permitted under the Williamson Act or contract, local uniform rules or ordinances and exceed 2,500 square feet are material breaches of contract and may be subject to penalties of 25% of the value of the affected land and 25% of the value of any improvements.  Please read more about the material breach provisions of Government Code Section 51250.

      Does my County Participate?

      As of 2013, all counties except Del Norte, San Francisco, Inyo, and Yuba offer Williamson Act contracts.  Imperial County filed non-renewal on all Williamson Act contracts, effective January 2011, covering 117,246 acres; however, pursuant to GC Section 51246 the contracts remain in full force and effect until the contracts terminate. 

      What is the State’s Role?

      The Department of Conservation is responsible for interpretation of the Williamson Act, research of related issues and policies and technical assistance in implementing the Act.