Sonoma County Land for Sale

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

Land for sale in Sonoma County runs from small infill lots inside cities to rural residential parcels, agricultural acreage and large resource-zoned ranch land in the unincorporated county. Outside city limits, Permit Sonoma’s zoning code tells you how many homes a parcel can hold, and water and septic decide whether you can actually build one. Check those three things, plus Fire Safe road access, before you price the land.

At a glance

Where to look in Sonoma County

Land listings follow the county’s mix of city, rural residential and agricultural zoning. A few ways to think about the search:

• Inside city limits. Lots in Santa Rosa real estate, Petaluma real estate, Healdsburg real estate and Sebastopol real estate follow each city’s zoning code, not the county’s, and usually connect to city water and sewer. Confirm the jurisdiction first; the Parcel Search tool tells you whether a parcel is in a city or the unincorporated county.
• West County. Rural parcels around Occidental real estate, Forestville real estate and Cazadero real estate are generally county-zoned, often on private wells and septic, and often reached by private roads.
• Along the coast. Near Bodega real estate, Jenner real estate and The Sea Ranch real estate, check whether the zoning carries "CC". Coastal Zone parcels have their own zoning chapter and coastal permit regulations.
• Valleys and wine country. Acreage near Glen Ellen real estate and Kenwood real estate is frequently in agricultural zones (LIA, LEA, DA) or AR. If you are buying for grapes, start with our Sonoma County agricultural zoning guide.

For a broader look at towns and housing types, see the Sonoma County where-to-live guide.

What to check before you buy

Zoning and density

Permit Sonoma lists the county’s base districts outside the Coastal Zone, including three agricultural districts (Land Intensive Agriculture, Land Extensive Agriculture and Diverse Agriculture), Agriculture and Residential (AR), Rural Residential (RR), Resources and Rural Development (RRD) and Timberland Production (TP), plus combining districts layered on top (Permit Sonoma county zones).

The numbers after the letters matter as much as the letters. In rural areas the number is acres per dwelling unit, so "RRD 60" allows one unit per 60 acres. A second number sets the minimum lot size for a subdivision: "AR B6 10/3" allows one unit per 10 acres with a 3-acre minimum, and "RRD CC B6 160/240" allows one unit per 160 acres with a 240-acre minimum (Permit Sonoma). Read the district’s rules in Chapter 26 (or 26C on the coast) before assuming you can split a parcel or add homes. Our guide to subdividing land in Sonoma and Napa goes further.

Williamson Act contracts

The Parcel Search tool shows whether a parcel is under a Williamson Act contract. The state Department of Conservation says a contract is binding on all later purchasers, renews automatically every year unless nonrenewed, and runs a minimum of 9 years (18 for a Farmland Security Zone). Cancellation carries a fee of 12.5% of current fair market value for a standard contract (DOC Williamson Act FAQ). Contracted land must stay in agricultural use, so it is not a shortcut to a residential lot. More in our Williamson Act guide.

Wells and groundwater

You need a Permit Sonoma permit to drill, deepen or abandon a well. The county’s amended well rules took effect May 18, 2023. All new wells must meet basic water-conservation conditions, including a 2,500-square-foot limit on existing lawn. Wells in the Public Trust Review Area that raise total site groundwater use above 2 acre-feet per year require a county finding that they won’t harm public trust resources (Permit Sonoma well ordinance).

There is also litigation. Permit Sonoma reports that a December 2024 court order required the county to suspend non-emergency well permits, and that the Court of Appeal granted a temporary stay in March 2025. Check the county page for the current status before you count on drilling a new well. The Parcel Search tool shows a groundwater availability classification, and the Santa Rosa Plain, Petaluma Valley and Sonoma Valley each have a groundwater sustainability agency. See Sonoma County groundwater rules and wells, septic and rural utilities in Sonoma County.

Septic feasibility

Most rural land depends on an onsite wastewater treatment system (OWTS). The county’s OWTS Manual requires evaluation of soil depth and type, percolation rate and groundwater elevation. Under the revised manual, a design professional does this work and submits the results in the OWTS design report with the permit application. Each test has an effective radius (50 feet for soil and groundwater, 25 feet for percolation), and together they define where the system can go. The North Coast Regional Water Board approved the county’s Local Area Management Program and manual in June 2026 (Permit Sonoma OWTS Manual). On raw land, make septic testing a contingency.

Fire Safe roads, driveways and water

The State Minimum Fire Safe Regulations (14 CCR 1270 et seq.) apply to new residential, commercial and industrial buildings in the State Responsibility Area approved after January 1, 1991, and in Very High Fire Hazard Severity Zones approved after July 1, 2021. They also apply to new parcels, use permits and new roads, and to building permits on older parcels where access conditions were never imposed (14 CCR 1270.03). Sonoma County enforces them along with its own Fire Safety Ordinance (Chapter 13) and defensible-space rules (Chapter 13A). When a project can’t meet every technical standard, the county reviews the whole project, offsite roads included, for equivalent fire safety (Permit Sonoma Fire Safe Regulations). A narrow shared road can be the costliest surprise on a rural lot. See fire hazard severity zones in the North Bay.

Road access and shared roads

Many rural Sonoma parcels sit on private roads or easements. Under Civil Code 845, easement owners must keep a private right-of-way in repair, and absent a written agreement they share the cost in proportion to use (text via california.public.law). Ask the title company for recorded easements and any road maintenance agreement, and walk the route with your contractor. Our guide to private road maintenance agreements in California covers what a good agreement includes.

How we approach a land purchase

1. Pull the Parcel Search report and read the full zoning designation.
2. Get the preliminary title report and recorded easements.
3. Write septic feasibility, well (or water-service) and Fire Safe access review into your contingencies.
4. Talk with Permit Sonoma planning before you remove contingencies if you plan to subdivide, add units or build on a constrained site.

Our step-by-step guide to buying land in California and building lots and ADUs in Sonoma County walk through the sequence. When you’re ready, start on our buyer services page.

Questions people ask

How do I find out what a Sonoma County parcel is zoned?

Use Permit Sonoma’s Parcel Search. For unincorporated parcels it shows zoning and land use codes, groundwater availability and Williamson Act status. If the parcel is inside a city, the city’s planning department sets the zoning.

What does a zoning code like "RRD 60" mean?

In rural areas the number is acres per dwelling unit, so RRD 60 allows one unit per 60 acres. A second number, as in "AR B6 10/3", sets the minimum lot size for a subdivision.

Can I drill a new well on land I buy?

You need a Permit Sonoma well permit, and wells in the Public Trust Review Area face more review if they push site use above 2 acre-feet a year. Non-emergency well permitting has also been affected by litigation since late 2024, so check the county’s well ordinance page for the current status first.

How do I know if a lot will pass a septic test?

Only testing tells you. A design professional evaluates soil depth, percolation rate and groundwater elevation and submits the results with the septic application under the county’s OWTS Manual.

Do Fire Safe regulations apply to my parcel?

They apply to new construction in the State Responsibility Area, and to construction approved after July 1, 2021 in Very High Fire Hazard Severity Zones. Contact Permit Sonoma’s Fire Prevention division to confirm requirements for a specific parcel.

What if the land is under a Williamson Act contract?

The contract stays with the land when it sells and keeps it in agricultural use. Ending one takes either nonrenewal, a period of years, or cancellation with a fee of 12.5% of fair market value for a standard contract.

Is a parcel near the coast harder to build on?

Coastal Zone parcels carry "CC" zoning under Chapter 26C and the county’s coastal permit regulations. Expect an extra layer of review and talk with planning early.

Who maintains a private road to the property?

Unless a recorded agreement says otherwise, Civil Code 845 has easement users share maintenance in proportion to use. Ask for the road agreement during escrow.

Sources & notes

1. Permit Sonoma, Zoning codes and density numbers and Parcel Search.
2. Permit Sonoma, County zones (non-Coastal Zone).
3. Permit Sonoma, Coastal Zone (CC) zoning.
4. Permit Sonoma, Well ordinance update. Includes litigation status as of the page’s last update.
5. Permit Sonoma, OWTS Manual and LAMP.
6. Permit Sonoma, Fire Safe Regulations.
7. California Code of Regulations, Title 14, § 1270.03, scope (Board of Forestry and Fire Protection).
8. California Department of Conservation, Williamson Act FAQ (2024).
9. California Civil Code § 845 (text via california.public.law).

Notes: Rules for land inside incorporated cities come from each city, not Permit Sonoma. This page has no prices or market figures. Well permitting status can change with the court case, so check the county page.

General information, not legal, tax or lending advice. Updated November 2026. Primary sources are linked in this guide.

Related: Sonoma County real estate · Where to live in Sonoma County · Buying land in California · Private road maintenance agreements · Sonoma County agricultural zoning