Buying Farm Land in California

Three different water-rights systems can serve the same stretch of the Central Valley

California is unusual in running a dual water-rights system where riparian rights and appropriative (prior-appropriation) rights coexist, layered under two large public water-delivery systems in much of the Central Valley. A riparian right belongs to land that physically borders a natural watercourse and generally requires no permit, but it only allows reasonable use on that adjoining parcel -- riparian water can't be diverted and piped or canaled to a non-adjacent tract, and in a shortage, riparian users generally share the cutback proportionally among themselves rather than by seniority. An appropriative right, by contrast, is a permitted right (administered by the State Water Resources Control Board) governed by strict seniority -- 'first in time, first in right' -- and unlike a riparian right, it can be exercised on land away from the watercourse and can be senior or junior to other appropriative rights regardless of where the land sits.

On top of both of those, a large share of Central Valley farmland doesn't rely on a direct riparian or appropriative right at all -- it receives water under a long-term delivery contract with the federal Central Valley Project (CVP, run by the Bureau of Reclamation) or the State Water Project (SWP, run by the California Department of Water Resources), both of which capture water behind northern dams and move it south through hundreds of miles of canals. The CVP alone delivers water to roughly 3 million acres of California farmland under these contracts. Critically, a CVP or SWP contract is not the same legal instrument as a riparian or appropriative right held directly by the landowner -- it's an allocation from the project's own water rights, administered by the district or agency that holds the actual contract, and annual allocation percentages can and do vary year to year with hydrology, regulatory constraints, and (as the Friant Division example on our Fresno County page shows) settlement or litigation history specific to that project.

Why this matters before you value a specific tract

For a buyer, the practical consequence is that 'this land has water' is not a single, checkable fact in the Central Valley -- it can mean a riparian right (reliable in most years, but legally limited to on-parcel use and not transferable), an appropriative right with a specific priority date (which determines how early it gets cut in a shortage), or CVP/SWP contract water delivered through a local irrigation or water district (reliable only to the extent that year's project-wide allocation is reliable, and subject to the delivering district's own rules, not the landowner's own priority). These aren't interchangeable, and a parcel's water reliability in a drought year depends enormously on which category applies. Ask the seller, the county, and (where relevant) the delivering irrigation district directly which category of right serves the specific parcel, its priority date if appropriative, and its recent actual delivery history if it's project contract water -- a real estate listing describing land as simply 'irrigated' rarely spells this out on its own.

The Williamson Act: California's statewide agricultural-preservation tax contract

Separate from water rights, California runs a genuinely distinctive statewide program affecting farmland taxation: the California Land Conservation Act of 1965, universally known as the Williamson Act. Under it, a county enters into a contract with a landowner that restricts the enrolled parcel to agricultural or compatible open-space use, and in exchange the county assessor values the land based on its restricted agricultural use rather than its full market value -- often a substantial property tax reduction relative to unrestricted market-value assessment. A Williamson Act contract runs on an automatic annual renewal structure: it starts with an initial term (commonly ten years) and renews for another year automatically each year unless either party files a formal notice of non-renewal, so absent action the contract effectively always has close to its full initial term still remaining.

This is directly relevant to a buyer in two opposite ways. If a parcel you're considering is already under contract, you're generally bound by its restrictions and its tax treatment as the new owner -- the contract runs with the land, not the seller, and getting out of it before the term naturally lapses through non-renewal generally means either a multi-year non-renewal wind-down or a contract cancellation, the latter of which can trigger a substantial cancellation fee designed to recapture some of the tax benefit received. Recent state legislative activity has also continued to expand what enrolled land can be used for without breaking the contract -- including proposals to broaden solar-use easements (a related mechanism allowing certain renewable energy uses on Williamson Act land) to cover energy storage and related facilities -- so the program is still actively evolving rather than frozen as originally written in 1965. If a parcel you're considering is not currently enrolled, ask the county agricultural commissioner or assessor whether it's eligible and what enrolling it would do to both the property tax bill and your future flexibility to convert the land to a non-agricultural use.

What to verify before buying California farmland

• Which category of water right (riparian, appropriative, or CVP/SWP contract) serves the specific parcel, its priority date if appropriative, and its recent delivery reliability if it is project contract water.
• Whether the parcel is currently under a Williamson Act contract with the county, and if so, its term, renewal status, and any restrictions on non-agricultural use.
• If not currently enrolled, whether the parcel is eligible for Williamson Act enrollment and what that would mean for the tax bill and future use flexibility.
• The parcel's Groundwater Sustainability Agency status under SGMA (see our California state hub) as a separate, additional check on the parcel's overall water picture.