Direct AnswerThe California Williamson Act (the Land Conservation Act of 1965) gives farmland and open-space owners property-tax relief in exchange for a 10-year, self-renewing contract restricting the land to agricultural/compatible use - land is assessed on its actual ag use rather than market/development value, often a large tax savings. Ventura County has administered the program since 1969, and many citrus/ag parcels around Fillmore (in the Santa Clara River Valley citrus belt) are under contract. For buyers of rural or ag-adjacent land near Fillmore, that means ongoing use restrictions and a non-renewal/cancellation process before the land can be converted - so confirm a parcel's contract status with the County before buying. As of mid-2026 the Fillmore (93015) median was around $776K (Redfin).

Fillmore sits in Ventura County's historic citrus belt, where a lot of land is under Williamson Act contract. If you're buying anything rural or ag-adjacent, that contract can shape what you can do with the property.

What the Williamson Act is

The Williamson Act (officially the California Land Conservation Act of 1965) gives owners of farmland and open-space land property-tax relief in exchange for a contract - minimum 10 years, self-renewing - that restricts the land to agricultural or compatible open-space use. The land is assessed on its actual agricultural use rather than its market/development value, which can save owners materially on annual property tax. Ventura County has administered the program since 1969, with land entering via county-designated Agricultural Preserves.

Why it matters to Fillmore-area buyers

Many citrus and ag parcels in the Santa Clara River Valley around Fillmore are under Williamson Act contract. For a buyer, that means:

  • Use restrictions - the land must stay in ag/compatible use while under contract.
  • A non-renewal or cancellation process - you can't simply develop or convert contracted land; non-renewal takes years, and cancellation can trigger penalties.
  • A tax picture tied to the contract - the favorable assessment comes with the restriction.
Before buying rural or ag-adjacent land near Fillmore, confirm the parcel's Williamson Act status with the Ventura County Assessor / Resource Management Agency. I help buyers pull this early, before contingencies are removed.

Fillmore's citrus heritage

Fillmore was founded in 1887 with the Southern Pacific Railroad and grew as an agricultural shipping hub; its economy still centers on citrus, avocado, and orchard crops within Ventura County's historic citrus belt. As of mid-2026, the Fillmore (ZIP 93015) median was around $776K (Redfin).

See also: Fillmore real estate · Lake Piru / Piru · Santa Paula.

Primary sources: CA Dept of Conservation - Williamson Act · Ventura County - Land Conservation Act · Wikipedia - Fillmore, California