Commercial Real Estate in Upper Lake: Historic Main Street, Area Plan Policies and Sewer Limits

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

Upper Lake is an unincorporated town at the north end of Clear Lake, on Highway 20 at the gateway to the Mendocino National Forest. Its commercial property is a compact historic Main Street of storefronts, restaurants, inns and antique shops, plus highway-facing service sites and agricultural and winery land in the surrounding valleys. Lake County zoning and the area plan’s downtown policies decide what a building can be used for, and sewer capacity has long limited growth. Confirm district, combining districts and utility service for every parcel.

Who controls the parcel

There is no city government. Lake County’s Community Development Department applies the county zoning ordinance. The Upper Lake–Nice Area Plan, listed on the county’s plans page, treats the Upper Lake community area as Special Study Area No. 1. The posted copy is marked draft and does not show an adoption date, so ask the county which version governs. Other agencies:

• Water: the Upper Lake County Water District, which the plan says draws from two wells (p. 3-5).
• Sewer: the plan says cease-and-desist orders on the Northwest Treatment Facility limit further development (p. 2-10). Confirm current capacity with Lake County Special Districts.
• Fire: the plan notes the Upper Lake Fire District collects development fees under county Ordinance 2114 of October 1992.

Tribal governments in the area, including the Habematolel Pomo of Upper Lake and the Upper Lake Pomo named in the county Housing Element, have their own jurisdiction over trust land, which county zoning does not cover. See our Lake County commercial guide for countywide context.

Upper Lake zoning for commercial and mixed use

The area plan says Upper Lake’s community area was designated Commercial (CM and CH) and Urban or Suburban Residential over the prior two decades (p. 2-10). The surrounding reclamation lands are designated Agriculture. It also eliminated the "U" Unclassified and "MH" Mobilehome districts in the planning area (p. 1-1). The county districts that implement those designations:

The plan also recommends a professional overlay along Washington Street south of First Street and along Sabini Street, which would allow offices on residential-scale lots there. Confirm whether that overlay was mapped.

Main Street: design review and historic character

Upper Lake’s downtown is its main commercial asset, and the area plan protects it closely:

• Downtown first. The plan aims to keep the historic downtown economically viable, and to diversify commercial growth without hurting it.
• Western town theme. Policy 3.5.2d requires Main Street commercial development to follow the plan’s design review guidelines, which call for a "western town" theme. A Design Review combining district is recommended, with guidelines in Appendix A.
• Streetscape. The plan supports street trees, sign size limits, covered storm drains and undergrounding utilities along the whole length of Main Street (Policies 3.5.2b and 3.5.2c).
• Historic preservation. Policy 3.5.1a calls for historic preservation designations and HP combining zoning where appropriate. Under the county’s Article 38, alterations, demolition, signs and new structures on HP-zoned property need a major use permit after Cultural Resource Commission review, which takes up to 40 days. Registered sites may use the State Historic Building Code.
• History. The first business, a blacksmith shop, opened in 1856. The town site was laid out in 1866, and a 1924 fire destroyed much of downtown (pp. 2-8 to 2-9). Many current buildings date from the rebuilding.
• Service uses screened. Industrial and service commercial uses need screening and roadway setbacks under Policy 3.5.2e.

Flood, sewer, scenic and lodging issues

• Drainage. The plan reports localized flooding in Upper Lake from inadequate drainage and calls for a Master Drainage Plan and limits on new development in flood-prone areas (Section 4.2). Check the FEMA zone and site drainage.
• Sewer limits. Because of the treatment facility orders noted above, a change to a restaurant or brewpub can depend on sewer capacity. Get written capacity confirmation before closing.
• Scenic Highway 20. The plan identifies Highway 20 and county roads near Upper Lake as potential scenic routes and calls for protecting viewsheds (Policy 3.5.2a). Signs and frontage design may be reviewed more closely.
• Creeks. The Waterway combining district bars development within 30 feet of perennial streams and 20 feet of intermittent streams without an exception.
• Lodging and forest visitors. Upper Lake is the main access to the southern Mendocino National Forest, about 3.5 miles north (p. 2-9), and the plan names agriculture and tourism as the area’s leading economic forces. Stays of 30 days or less owe the county’s 9% transient occupancy tax.

Transfer tax, business tax and property tax

The Lake County Assessor-Recorder fee schedule lists the documentary transfer tax at $1.10 per $1,000. Upper Lake is unincorporated, so no city tax applies. We did not verify a county business license tax. A sale generally triggers Proposition 13 reassessment, and farmland may be under a Williamson Act contract.

Due diligence that matters in Upper Lake

Start with our commercial due diligence checklist, then add:

• Confirm sewer capacity and connection rights, and Upper Lake County Water District service.
• Ask whether the parcel carries HP or design review combining zoning, and get the Appendix A design guidelines.
• Check the tenant’s floor area and hours against the C1 or C2 by-right limits.
• Review the FEMA flood zone and on-site drainage.
• Confirm the parcel is under county jurisdiction, not tribal trust land.
• For lodging, confirm TOT registration and permitted room count.

Questions people ask

Sources & notes

1. Upper Lake–Nice Area Plan (posted draft) and Lake County Plans page
2. Lake County Zoning Ordinance: index, 16 CH, 17 CR, 18 C1, 19 C2, 37 Waterway, 38 HP
3. Lake County Assessor-Recorder Schedule of Fees
4. Lake County TOT Ordinance

Note: The area plan copy we read is labeled draft with no adoption date. Its sewer description predates current conditions, so confirm present sewer capacity and the status of the professional overlay and Design Review district with the county.

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

Related: Upper Lake real estate guide · Multifamily property in Upper Lake · Commercial real estate services