Commercial Real Estate in The Springs: Highway 12 Corridor Zoning and the Springs Specific Plan

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

The Springs is the string of unincorporated communities just north of the City of Sonoma, including Boyes Hot Springs, Fetters Hot Springs and Agua Caliente, tied together by the Highway 12 commercial corridor. Its commercial property is mostly older storefronts, taquerias and markets, auto and service businesses, small offices and a resort heritage that dates to the hot springs era. Because it sits outside city limits, the County of Sonoma decides what each parcel can do. Confirm zoning and services for any parcel with Permit Sonoma before relying on this page.

Who controls the parcel

• Zoning and building: Permit Sonoma, under County Chapter 26. The Official Zoning Database shows each parcel’s base zone and combining districts.
• The city line: South of Verano Avenue, parcels may be inside the City of Sonoma, which has its own code and growth boundary. See our Sonoma commercial guide.
• Water: Permit Sonoma’s water and sewer referral list names the Valley of the Moon Water District, whose area includes Boyes Hot Springs and El Verano.
• Sewer: Sonoma Water runs the Sonoma Valley County Sanitation District, which covers a 4,500-acre area, has operated since 1953 and holds a 3-million-gallon-per-day permitted capacity. Confirm that a given Springs parcel is connected.

The Springs zoning for commercial and mixed use

Corridor parcels use the County’s Article 10 commercial zones, adopted by Ordinance 6335 in February 2021 and last amended by Ordinance 6532 in October 2025.

Height and bulk. Table 10-2 caps height at 35 feet in every County commercial zone. A use permit can allow more, but the building cannot exceed the zone’s maximum building intensity, which is height multiplied by allowed lot coverage.

Design review and music. Design review applies to every allowed use outside the AS zone. Amplified live music needs a use permit in C2, LC and K, which matters for bars and event spaces.

The Springs Specific Plan

Permit Sonoma’s Springs Specific Plan page describes a plan area of about 178 acres between Agua Caliente Road and Verano Avenue, split by the Highway 12 corridor. The draft plan would:

• Rezone for a mix of homes and neighborhood-oriented commercial uses, with Highway 12 as a "main street."
• Create room for more than 700 housing units.
• Add commercial, office and recreation space and identify a community plaza site.
• Improve sidewalks, bike lanes and crosswalks.

The state CEQAnet record describes the plan area as an L-shaped area with a 1.6-mile Highway 12 mixed-use spine and a base along Donald and Harley streets. Full buildout is about 706 homes, 120 hotel rooms and up to 276,903 square feet of nonresidential space.

Status. The draft EIR circulated from May 18 to July 19, 2022, and the County page says it is being revised to expand analysis of wildfire evacuation and wastewater. CEQAnet lists no notice of determination. As of October 2026, treat the plan as proposed, not adopted. Current Article 10 zoning governs until the Board acts.

Highway 12 design guidelines

Corridor frontage already has its own design rules. Under Section 26-90-110, adopted by Ordinance 6057 in 2014, parcels fronting Highway 12 from Verano Avenue north to Agua Caliente Road carry an LG/SPR suffix. They follow the Springs Highway 12 Design Guidelines.

• Unlike the Russian River corridor, the section lists no exemption for small projects.
• Design review applies to ministerial work that changes exteriors or adds structures, to discretionary projects and to public projects.
• Signs, exterior lighting and work in the street right-of-way must also comply.

A facade refresh or new sign on the corridor is a design review item, not just a building permit.

Lodging, vacation rentals and visitor uses

• Hotels and resorts. These need a use permit in C2 or K, plus water and sewer capacity. The draft plan’s 120 hotel rooms are a planning estimate, not an entitlement.
• Vacation rentals. Permit Sonoma’s vacation rental page bars them in R1, R2 and R3 and in ADUs. In commercial zones, the County allows them only in existing single-family homes in C2, LC and K. Each needs a certified property manager, zoning permit, TOT number and license.
• Mixed-use buildings. Section 26-08-050 bars vacation rentals and other transient stays in multifamily projects of four or more units, so upstairs apartments cannot be run as nightly rentals.

Transfer tax, business tax and property tax

The County Recorder charges $0.55 per $500, less assumed loans. No city tax applies in the unincorporated Springs. Lodging operators collect County transient occupancy tax; we did not verify the rate. A change of ownership generally triggers Proposition 13 reassessment.

Due diligence that matters in The Springs

Start with our commercial due diligence checklist, then add:

• Confirm whether the parcel is unincorporated or inside the City of Sonoma.
• Pull the parcel’s base zone, any combining districts and the LG/SPR suffix from the zoning database.
• Read the draft Springs Specific Plan for the parcel, but underwrite on current zoning.
• Confirm sewer connection and capacity with Sonoma Water and water service with Valley of the Moon Water District.
• For a restaurant or bar, ask whether the use is permitted outright or needs a use permit, and whether live music is planned.
• For a resort or inn, read existing use permit conditions and TOT records.

Questions people ask

Sources & notes

1. County Code Article 10, Commercial Zones and Article 90, Local Area Development Guidelines
2. County Code Article 08, Residential Zones
3. Permit Sonoma, Springs Specific Plan
4. CEQAnet, SCH 2018062068
5. Permit Sonoma, vacation rentals
6. Permit Sonoma water and sewer referral list
7. Sonoma Valley County Sanitation District newsletter, 2026
8. Sonoma County Recorder, documentary transfer tax

Note: We did not read the Springs Highway 12 Design Guidelines document, map which corridor parcels carry which zone, read the draft plan’s development standards, confirm the sanitation district’s boundary for each Springs parcel, or verify TOT and connection fees. The description of local businesses is a general observation. See also our Sonoma County commercial guide and Sonoma County multifamily guide.

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

Related: The Springs real estate guide · Multifamily property in The Springs · Commercial real estate services