Commercial Real Estate in Larkfield-Wikiup: Old Redwood Highway Zoning, Sewer Service and Post-Fire Land Use

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

Larkfield-Wikiup is an unincorporated community north of Santa Rosa, between the city and the Sonoma County Airport area. Its commercial property is concentrated along Old Redwood Highway and near Mark West Springs Road, with neighborhood retail, offices and service businesses in a community that has been rebuilding since the October 2017 fires. Although many parcels carry Santa Rosa mailing addresses, the land is under Sonoma County, so confirm jurisdiction and zoning with Permit Sonoma before relying on this page.

Who controls the parcel

Permit Sonoma applies the county zoning code here, and county records describe the area as the Larkfield urban service area, meaning it is planned for urban-level sewer and water rather than septic-and-well development. Sewer service comes from the Airport/Larkfield/Wikiup Sanitation Zone, run by Sonoma Water. Just north and west, the county’s Airport Industrial Area Specific Plan governs the business park land near the airport, and the county is updating that plan. Because "Santa Rosa, CA 95403" addresses straddle the city line, check the county parcel record before assuming city rules or the Santa Rosa transfer tax apply. For countywide context see our Sonoma County commercial guide.

Larkfield-Wikiup zoning for commercial and visitor uses

These districts appear on recent Larkfield-Wikiup county files; the county’s zoning district list places commercial zones in Article 10 of Chapter 26.

District	Intended uses	Larkfield-Wikiup notes
C2 Retail Business and Service	Retail stores, personal and business services, offices	Mapped on Old Redwood Highway frontage in the urban service area
C3 General Commercial	Broader commercial and service uses than C2	A 1.69-acre Old Redwood Highway parcel sought rezoning from C2 to C3 in 2022
VOH Valley Oak Habitat (combining)	Protection and replacement of valley oaks	Shown with C2 on Old Redwood Highway; affects site planning
K Recreation and Visitor-Serving Commercial	Recreation, lodging and visitor services	Formerly covered the Wikiup Golf Course site
R1 and DA (in the Wikiup Commons proposal)	Homes and open space or park	Proposed replacements for K on the former golf course
Airport Industrial Area Specific Plan	Business park and industrial uses near the airport	Plan area adjacent to the community; update under way

Old Redwood Highway and the Larkfield urban service area

A recent rezoning. In May 2022 the Board of Zoning Adjustments acted 5-0 (Resolution 22-006) on a request to rezone 5390 Old Redwood Highway, a 1.69-acre parcel zoned C2 with a Valley Oak Habitat overlay, to C3 General Commercial to allow future development. A rezoning usually needs final Board of Supervisors action, so confirm the current zoning on the parcel record rather than relying on the 2022 request.

What the corridor means for buyers. Commercial parcels here are in an urban service area with public sewer, which lets them support restaurants and other higher-water uses that a septic site in rural Sonoma County could not. The Valley Oak Habitat overlay can still shape a redevelopment, since mature oaks may need to be preserved or replaced.

Fire rebuild. The 2017 Sonoma Complex fires heavily damaged the Larkfield Estates neighborhood, as Sonoma Water notes on its sanitation zone page. During the rebuild, the county adopted a temporary fire recovery ordinance that included limits on new vacation rentals; per Permit Sonoma’s list, that section was adopted December 14, 2021 and expired December 31, 2022.

The Wikiup Golf Course site

The former Wikiup Golf Course, which closed in 2015, is the area’s largest visitor-serving commercial site. Under the county’s Wikiup Commons application, about 30.3 acres would move from K zoning and a Recreation and Visitor Serving Commercial plan designation to R1 for 29 single-family lots on about 4.74 acres, with about 25.55 acres in Diverse Agriculture as open space or park. The application needs a General Plan amendment, zone change, subdivision, use permit and design review, staff has determined an environmental impact report is required, and the Board of Supervisors must approve. It shows that K-zoned recreation land in Larkfield-Wikiup may be more likely to change use through rezoning than to stay as a commercial recreation site.

Sewer service and consolidation

Capacity. The Airport/Larkfield/Wikiup zone began operating in 1983, covers about 2,100 acres and has a tertiary plant with a design capacity of 900,000 gallons per day; all its recycled water goes to irrigation.
Larkfield Estates. That neighborhood lies inside the zone boundary and is eligible to connect, and Sonoma Water runs a voluntary sewer extension program there.
Consolidation. Sonoma Water describes a proposed consolidation that would transfer some or all of the zone to the Windsor Water District, whose reclamation facility would then treat the wastewater. Ask who will issue sewer capacity and connection fees for your project if that change proceeds.

Transfer tax, business tax and property tax

The Sonoma County Clerk-Recorder charges $0.55 per $500 of value, after deducting assumed loans. Santa Rosa adds $2.00 per $1,000 inside its limits, but an unincorporated Larkfield-Wikiup parcel should declare "unincorporated" and pay only the county tax. A purchase is generally a change in ownership under Proposition 13, so budget reassessment to the price. We did not verify county business license requirements.

Due diligence that matters in Larkfield-Wikiup

Start with our commercial due diligence checklist, then add:

Confirm the parcel is unincorporated and not inside Santa Rosa.
Pull the zoning string, including any VOH overlay, and the final outcome of any recent rezoning.
Get a sewer capacity letter from Sonoma Water and ask about the Windsor consolidation.
Review fire-rebuild permits and final inspections for any structure rebuilt after 2017.
Near the airport, check the airport land use plan and the specific plan update.
Check FEMA flood mapping along Mark West Creek and its tributaries.

Questions people ask

Is Larkfield-Wikiup part of Santa Rosa?

No. It is unincorporated Sonoma County, even though many addresses read Santa Rosa.

What zoning is on Old Redwood Highway in Larkfield?

County files show C2 Retail Business and Service, in one case with a Valley Oak Habitat overlay, and a 2022 request to rezone a parcel to C3.

Does Larkfield-Wikiup have sewer?

Yes, through the Airport/Larkfield/Wikiup Sanitation Zone, which has a 900,000-gallon-per-day tertiary plant.

What is happening with the Wikiup Golf Course?

An application would rezone it from K to R1 for 29 lots and DA for open space, pending an EIR and Board of Supervisors approval.

Do I pay Santa Rosa transfer tax in Larkfield?

Not on an unincorporated parcel; only the county’s $0.55 per $500 applies.

Will the sewer provider change?

Possibly. Sonoma Water describes a proposed transfer of some or all of the zone to the Windsor Water District.

Does Diamond handle commercial property in Larkfield-Wikiup?

Contact Matthew Martinez to discuss buying, selling or leasing commercial property in Larkfield-Wikiup.

Sources & notes

Note: We did not confirm whether the 2022 C3 rezoning or the Wikiup Commons application received final approval, and we did not read the county code text for C2, C3 or K. Mark West Creek flood mapping, water provider and airport plan boundaries were not verified. Corridor descriptions are general.

This page is general information, not legal or tax advice. Last reviewed October 2026 by Matthew Martinez.

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