Sonoma Municipal Code § 19.10.030 Overlay zoning districts and standards

This chapter establishes the zoning districts within the city, determines how the zoning districts are applied to property on the zoning map, and establishes planning permit requirements for new land uses and development. (Ord. 2003-02 § 3, 2003).

The city of Sonoma shall be divided into the zoning districts described in this section, to implement the city of Sonoma General Plan land use designations. The following zoning districts are hereby established, and are shown on the official zoning map (see SMC 19.10.040). The uses of land allowed within each zoning district and the planning permit requirements applicable to the allowable uses are determined by SMC 19.10.050, Allowable land uses and permit requirements.

Table 2-0. Zoning Districts Established

A. Residential Zoning Districts.

1. R-HS (Residential – Hillside) District. The R-HS zoning district is applied to hillside areas of the city that are suitable for very-low density single-family residential and agricultural land uses. The maximum allowable density is one dwelling unit per 10 acres. The R-HS zoning district is consistent with the hillside land use designation of the General Plan.

2. R-R (Residential – Rural) District. The R-R zoning district is applied to areas where the city intends to preserve low density, single-family neighborhoods with rural character. The maximum allowable density is two dwelling units per acre. The R-R zoning district is consistent with the Rural

Residential land use designation of the General Plan.

3. R-L (Residential – Low Density) District. The R-L zoning district is applied to areas primarily suitable for detached single-family dwellings and duplexes. Clustered housing and other types of residential development may be allowed with a planned development permit (SMC 19.54.070). The minimum density for new residential construction is two dwelling units per acre and the maximum density is five dwelling units per acre. The R-L zoning district is consistent with the low density residential land use designation of the General Plan.

4. R-S (Residential – Sonoma) District. The R-S zoning district is typically applied to parcels of three acres or more in size, and is intended to provide areas suitable for a broad range of housing types, including housing affordable to low and moderate income households. The R-S zoning district is intended to promote creativity in project design, variety in lot sizes and unit types, and development that will fit in with surrounding neighborhoods. The minimum density for new residential construction is three dwelling units per acre and the maximum density is eight dwelling units per acre. Subject to use permit review, limited neighborhood-serving commercial uses may be allowed, in accordance with SMC 19.14.030, Neighborhood commercial development. The R-S zoning district is consistent with the Sonoma residential land use designation of the General Plan.

5. R-M (Residential – Medium Density) District. The R-M zoning district is applied to areas appropriate for medium density, multifamily residential development. New single-family dwellings are prohibited as of July 1, 2023, but units in existence prior to that date can continue as a legal conforming use. New accessory dwelling units and junior accessory dwelling units are allowed. The minimum density for new residential construction is seven dwelling units per acre and the maximum density is 11 dwelling units per acre. The R-M zoning district is consistent with the medium density residential land use designation of the General Plan.

6. R-H (Residential – High Density) District. The R-H zoning district is applied to areas suitable for high density residential development, particularly in areas of transition between commercial or mixed use zoning districts. New single-family dwellings and duplexes are prohibited as of July 1, 2023, but units in existence prior to that date can continue as a legal conforming use. The minimum density for new residential construction is 11 dwelling units per acre and the maximum density is 15 dwelling units per acre. The R-H zoning district is consistent with the high density residential land use designation of the General Plan.

7. R-O (Residential – Housing Opportunity) District. The R-O zoning district is applied to areas appropriate for very high density residential development. The intent of this zoning district is to provide areas suitable for low and very low income households and for high density attached housing types. Single-family dwellings and duplexes are prohibited. The minimum density for new residential construction is 15 dwelling units per acre and the maximum density is 25 dwelling units per acre. The R-O zoning district implements the housing opportunity site land use designation of the General Plan.

8. R-P (Residential – Mobile Home Park) District. The R-P zoning district is applied to the city’s three mobile home parks. Only uses consistent with the continued operation of these sites as mobile home parks are allowed. The maximum residential density is seven dwelling units per acre. The R-P zoning district is consistent with the mobile home park land use designation of the General Plan.

B. Commercial Zoning Districts.

1. C (Commercial) District. The C zoning district is applied to areas appropriate for a range of commercial land uses including retail, tourist, office, and mixed uses. The C zoning district may accommodate multifamily dwellings but single-family dwellings and duplexes are prohibited. The maximum residential density is 20 dwelling units per acre. The C zoning district is consistent with the commercial land use designation of the General Plan.

2. C-G (Commercial-Gateway) District. The C-G zoning district is applied to the Four Corners and Verano Triangle areas, prominent commercial entrances into the city that require sensitive site design. The maximum residential density is 20 dwelling units per acre. The C-G zoning district is consistent with the gateway commercial land use designation of the General Plan.

3. Residential Component.

a. In applications for new development on properties of one-half acre in size or larger for which a discretionary permit is required, a residential component shall be required, except in either of the following circumstances:

i. The replacement of a commercial use within an existing tenant space with another commercial use.

ii. Additions up to 30 percent of existing historic structures that are listed, or eligible to be listed, on the National Register of Historic Places, the California Register of Historical Resources and/or the city of Sonoma Inventory of Historic Sites and Structures where the addition would not impact the historic designation.

b. A residential component shall be equal to 100 percent of the floor area of the commercial component. The residential component may be wholly or partially satisfied through payment of a residential component fee, subject to approval by the planning commission. The residential component fee shall be paid per square foot of required residential component and shall be established by resolution of the city council and paid into the housing trust fund. Circumstances in which the residential component may be wholly or partially satisfied by the residential component fee include, but are not limited to, the following:

i. The presence of existing uses or conditions incompatible with residential development on or adjacent to the property for which a new development is proposed.

ii. Existing property characteristics, including size limitations and environmental characteristics, that constrain opportunities for residential development or make it infeasible.

iii. Limitations imposed by other regulatory requirements, such as the growth management ordinance.

C. Mixed Use Zoning District.

1. MX (Mixed Use) District. The MX zoning district is intended to allow for multifamily dwellings, both separately and in conjunction with commercial and office development, in order to increase housing opportunities, reduce dependence on the automobile, and provide a pedestrian presence in commercial areas. Under this designation, longstanding commercial and industrial uses in otherwise residential areas may be preserved and, subject to use permit review, modified or intensified. New single-family dwellings and duplexes are prohibited as of July 1, 2023, but units in existence prior to that date can continue as a legal conforming use. The maximum residential density is 20 dwelling units per acre. The MX zoning district is consistent with the Mixed Use land use designation of the General Plan.

2. Residential Component.

a. In applications for new development for which a discretionary permit is required, a residential component is required, unless waived by the planning commission. A residential component shall be required, except in either of the following circumstances:

i. The replacement of a commercial use within an existing tenant space with another commercial use.

ii. Additions up to 30 percent of existing historic structures that are listed, or eligible to be listed, on the National Register of Historic Places, the California Register of Historical Resources and/or the city of Sonoma Inventory of Historic Sites and Structures where the addition would not impact the historic designation.

b. A residential component shall be equal to 100 percent of the floor area of the commercial component. The residential component may be wholly or partially satisfied through payment of a residential component fee, subject to approval by the planning commission. The residential component fee shall be paid per square foot of required residential component and shall be established by resolution of the city council and paid into the housing trust fund. Circumstances in which the residential component may be wholly or partially satisfied by the residential component fee include, but are not limited to, the following:

i. The presence of existing uses or conditions incompatible with residential development on or adjacent to the property for which a new development is proposed.

ii. Existing property characteristics, including size limitations and environmental characteristics, that constrain opportunities for residential development or make it infeasible.

iii. Limitations imposed by other regulatory requirements, such as the growth management ordinance.

3. Commercial Component. In applications for new development for which a discretionary permit is required, a commercial component may be required, unless waived by the planning commission. Circumstances in which a commercial component may be waived include, but are not limited to, the following:

a. The replacement, expansion, or alteration of a residential use within an existing residential or mixed use development.

b. The presence of existing uses or conditions incompatible with commercial development on or adjacent to the property for which a new development is proposed.

c. Existing property characteristics, including size limitations and environmental characteristics, that constrain opportunities for commercial development or make it infeasible.

d. Interference with the objective of maximizing housing opportunities, especially affordable housing and other housing types that meet community needs as identified in the housing element.

e. Limitations imposed by other development regulations, including applicable requirements and guidelines of the development code.

D. Special Purpose Zoning Districts.

1. A (Agriculture) District. The A zoning district is applied to existing agricultural areas within the city. The intent of the zoning district is to protect these parcels for productive agricultural uses. The maximum residential density is one dwelling unit per 10 acres. The A zoning district is consistent with the agricultural land use designation of the General Plan.

2. Pk (Park) District. The Pk zoning district is applied to parkland of a variety of types, from intensively developed playing fields and recreational facilities (including museums and recreation centers), to natural open spaces where development is limited to trails. The Pk zoning district is consistent with the park land use designations of the General Plan.

3. P (Public Facilities) District. The P zoning district applies to areas appropriate for a variety of public and quasi-public land uses. The P zoning district is consistent with the public land use designations of the General Plan.

4. W (Wine Production) District. The W zoning district is applied to winery facilities. Only winery-related land uses are suitable for this designation. The W zoning district is consistent with the wine production land use designation of the General Plan. (Ord. 03-2023 §§ 1(A), (B), 2023; Ord. 12-2022 § 1(A), 2022; Ord. 03-2016 § 3 (Exh. C), 2016; Ord. 03-2004 § 1, 2004; Ord. 2003-02 § 3, 2003).

A. Purpose. Overlay zoning districts regulate new and existing land uses by providing guidance for development in addition to the standards and regulations of the primary zoning district and subarea. These overlay districts apply to areas where important site, environmental, cultural, and other compatibility issues require particular sensitivity in project planning.

B. Applicability. The requirements of the overlay districts apply to proposed land uses and development in addition to all other applicable requirements of this development code. In the event of any perceived conflict between the requirements of the overlay districts and any other provision of this development code, the most restrictive shall control.

1. Mapping of Overlay Districts. The applicability of any overlay zoning district to a specific site is shown by the overlay zoning map symbol established by this section being appended as a suffix to the symbol for the primary zoning district on the zoning map (for example, R-L/H) or by the use of shading and other graphical means as depicted on the zoning map.

2. Allowed Land Uses, Permit Requirements, Development Standards. Except as may be provided by this development code for a specific overlay zoning district:

a. Any land use normally allowed in the primary zoning district by this chapter may be allowed within an overlay district, subject to any additional requirements of the overlay district;

b. Development and new land uses within an overlay district shall obtain the land use permits required by this chapter for the primary zoning district; and

c. Development and new land uses within an overlay district shall comply with all applicable development standards established by Division III, Project Design, and Division IV, General Site Planning and Development Standards.

C. Overlay Districts and Their Requirements.

1. /C (Creek Setback) District. The /C overlay district is intended to preserve the environmental integrity and riparian habitat of the city’s creeks, and to ensure that new land uses near the creeks are developed safely. Development within the /C overlay district shall be evaluated in accordance with the procedures, standards and guidelines set forth in SMC 19.40.020, Creekside development.

a. Applicability. The /C overlay district applies to areas identified on the zoning map adjacent to Sonoma, Nathanson, and Fryer Creeks.

b. Permit Requirements. Playgrounds, sports fields, erosion control projects, parking areas, and any other modifications to existing structures shall require use permit approval.

c. Special Standards. Proposed uses and structures shall be located above the adopted flood elevation standard in compliance with Chapter 14.25 SMC, Flood Damage Prevention Regulations. Disturbance of native vegetation shall be minimized and proposed development shall include a landscaping plan identifying appropriate riparian habitat enhancement measures.

2. /H (Historic) District. The /H overlay district is intended to preserve structures that are historically and/or culturally significant.

a. Applicability. The /H overlay district is applied to historic sites and areas as identified on the zoning map.

b. Permit Requirements for Increased Residential Densities and Alternative Uses. As set forth in Chapter 19.42 SMC, Historic Preservation and Infill in the Historic Zone, increased residential densities and limited office or commercial land uses may be allowed with use permit approval if found to be consistent with the intent of preserving existing historic structures and the historic context of the site.

c. Permit Requirements for New Construction, Additions, Renovations, and Relocations. Design review permit approval is required for specific types of development within the district as set forth in SMC 19.54.080, Design review.

d. Permit Requirements for Demolition. Demolitions of structures within the district require demolition permit approval as set forth in SMC 19.54.090, Demolition permit.

3. /O (Open Space) District. The /O overlay district is intended to recognize sites that are designated to remain substantially undeveloped and in a natural condition. This designation is only applicable to properties that are publicly owned or for which open space or development easements have been obtained.

a. Applicability. The /O overlay district is applied to sites and areas as identified on the zoning map.

b. Permit Requirements. The development of any new building or parking area shall require use permit approval.

c. Special Standards. New construction within the /O overlay district shall only be allowed if it is found that the natural character of the site and its value as open space will not be diminished. This designation is not intended to preclude environmental enhancement and restoration projects or the provision of public access, such as trails.

4. /P (Plaza Retail) District. The /P overlay district is intended to preserve the vitality of Sonoma’s historic downtown area as a predominantly retail center.

a. Applicability. The /P overlay district is applied to sites and areas as identified on the zoning map.

b. Permit Requirements for Office Uses. Use permit approval is required for the establishment or expansion of any office use, where not already allowed by use permit, within any new or existing ground-floor tenant space having frontage along a public street or a major pedestrian arcade (defined as the Mercato, the Place des Pyrenees, and the El Paso).

c. Findings for Office Uses. In order to approve a use permit as required under subsection (C)(4)(b) of this section, the planning commission must find, in addition to the basic use permit findings set forth in SMC 19.54.040(E), that the proposed use due to specific circumstances related to its size, nature or location will not detract from the retail and pedestrian character of its immediate environs or the plaza generally, or that the office use is necessary for the economic viability of the site or its surroundings.

d. Prohibition on Formula Restaurants, Large. Formula restaurants, large are prohibited within the plaza retail district. (Ord. 10-2025 § 2 (Exh. A), 2025; Ord. 06-2013 § 3, 2013; Ord. 03-2012 § 1(A), 2012; Ord. 08-2005 § 1, 2005; Ord. 2003-02 § 3, 2003).

The council hereby adopts the city of Sonoma Zoning Map (incorporated herein by reference). The boundaries of the zoning districts and overlay zoning districts established by SMC 19.10.020 and 19.10.030 shall be shown upon the zoning map. The zoning map shall be interpreted in compliance with SMC 19.02.020(C), Zoning Map Boundaries. (Ord. 2003-02 § 3, 2003).

A. Purpose. This section determines which land uses are allowed in each zoning district established by SMC 19.10.020, Zoning districts established, and the land use permit required to establish each use.

B. Allowed Land Uses. The uses of land allowed by this development code in each zoning district are identified in Tables 2-1, 2-2, 2-3 and 2-4, along with the type of planning permit required for each use. These tables provide for land uses that are:

1. Permitted subject to compliance with all applicable provisions of this development code, subject to first obtaining a zoning clearance (SMC 19.54.020), and any building permit or other administrative permit required by the municipal code. These are shown as “P” uses in the tables;

2. Allowed subject to the approval of a use permit (SMC 19.54.040), and shown as “UP” uses in the tables.

Note: where the last column in the tables (“Specific Use Standards”) includes a section number, the regulations in the referenced section apply to the use; however, provisions in other sections of this development code may also apply.

C. Uses Not Listed. Land uses that are not listed in the tables or are not shown in a particular zoning district are not allowed, except as otherwise provided by SMC 19.02.020(D), Rules of interpretation – Allowable Uses of Land), or SMC 19.03.030, Exemptions from Land Use Permit Requirements.

D. Standards for Parcels with Multiple Zoning Districts. Where an existing parcel is zoned in two or more zoning districts, each portion of the parcel in a separate district shall be developed/used in compliance with the requirements of the applicable district. (Ord. 07-2003 § 1, 2003; Ord. 2003-02 § 3, 2003).

Table 2-1. Residential Uses and Permit Requirements

Notes:

1.See SMC 19.10.050(C) regarding uses not listed. See Division VIII for definitions of the listed land uses.

2.New residential developments subject to the city’s growth management ordinance (Chapter 19.94 SMC).

3.Supportive and transitional housing shall be subject to those restrictions that apply to other residential dwellings of the same type in the same zone. For example, such housing structured as single-family is permitted in the R-HS, R-R, R-L and R-S residential zones, whereas supportive and transitional housing structured as multifamily is limited to the R-M and R-H residential zones and the mixed use zone.

4.Personal cultivation of cannabis (indoor and outdoor) only allowable in conjunction with residential use subject to SMC 19.50.032.

(Ord. 01-2023 § 1(B), 2023; Ord. 12-2022 § 1(B) (Exh. A(A)), 2022; Ord. 07-2022 § 3(A) (Exh. A(A)), 2022; Ord. 04-2019 § 4 (Exh. A(A)), 2019; Ord. 01-2019 (Exh. A), 2019; Ord. 08-2018 § 2 (Exh. A), 2018; Ord. 07-2018 § 3, 2018; Ord. 05-2018 § 3 (Exh. A), 2018; Ord. 01-2017 § 1 (Exh. A), 2017; Ord. 02-2014 § 2(A), 2014; Ord. 06-2010 § 1, 2010).

Table 2-2. Commercial Uses and Permit Requirements

Notes:

1.See SMC 19.10.050(C) regarding uses not listed. See Division VIII for definitions of the listed land uses.

2.New residential developments subject to the city’s growth management ordinance (Chapter 19.94 SMC).

3.Supportive and transitional housing shall be subject to those restrictions that apply to other residential dwellings of the same type in the same zone. For example, such housing structured as single-family is permitted in the R-HS, R-R, R-L and R-S residential zones, whereas supportive and transitional housing structured as multifamily is limited to the R-M and R-H residential zones and the mixed use zone.

4.Defined as new commercial construction or an addition to an existing commercial building, having an area of 1,000 square feet or greater.

5.Use permit required within the historic overlay zone.

6.Prohibited in /P plaza retail district. See SMC 19.50.035.

7.Personal cultivation of cannabis (indoor and outdoor) only allowable in conjunction with residential use subject to SMC 19.50.032.

8.No commercial cannabis activity may occur in these zoning districts unless and until a commercial cannabis business permit has been issued for that activity under Chapter 5.36 SMC.

(Ord. 12-2022 § 1(B) (Exh. A(B)), 2022; Ord. 07-2022 § 3(A) (Exh. A(B)), 2022; Ord. 01-2021 § 1(2), 2021; Ord. 04-2019 § 4 (Exh. A(B)), 2019; Ord. 01-2019 § 1 (Exh. A), 2019; Ord. 08-2018 § 2 (Exh. A), 2018; Ord. 07-2018 § 3, 2018; Ord. 05-2018 § 3 (Exh. A), 2018; Ord. 11-2017 § 1, 2017; Ord. 03-2014 § 2(A), 2014; Ord. 02-2014 § 2(B), 2014; Ord. 03-2012 § 1(B), 2012; Ord. 02-2012 § 2(A), 2012).

Table 2-3. Mixed Uses and Permit Requirements

Notes:

1.See SMC 19.10.050(C) regarding uses not listed. See Division VIII for definitions of the listed land uses.

2.New development in the mixed use zone shall include a residential component unless waived by the planning commission through use permit review (see SMC 19.10.020(C)).

3.Uses within these categories are allowed only if the planning commission finds that the use will not result in the encroachment of incompatible commercial uses within an established residential area.

4.New residential developments subject to the city’s growth management ordinance.

5.Single-family dwellings on an existing lot of record that predate July 1, 2023, are legal conforming uses.

6.On sites of one acre in size or larger.

7.Personal cultivation of cannabis (indoor and outdoor) only allowable in conjunction with residential use subject to SMC 19.50.032.

8.No commercial cannabis activity may occur in these zoning districts unless and until a commercial cannabis business permit has been issued for that activity under Chapter 5.36 SMC.

(Ord. 01-2023 § 1(B), 2023; Ord. 12-2022 § 1(B) (Exh. A(C)), 2022; Ord. 07-2022 § 3(A) (Exh. A(C)), 2022; Ord. 01-2021 § 1(2), 2021; Ord. 04-2019 § 4 (Exh. A(C)), 2019; Ord. 01-2019 § 1 (Exh. A), 2019; Ord. 08-2018 § 2 (Exh. A), 2018; Ord. 07-2018 § 3, 2018; Ord. 05-2018 § 3 (Exh. A), 2018; Ord. 11-2017 § 2, 2017; Ord. 01-2017 § 1 (Exh. A), 2017; Ord. 03-2014 § 2(B), 2014; Ord. 02-2014 § 2(C), 2014; Ord. 03-2012 § 1(C), 2012; Ord. 02-2012 § 2(B), 2012).

Table 2-4. Special Purpose Uses and Permit Requirements

Notes:

1.See SMC 19.10.050(C) regarding uses not listed. See Division VIII for definitions of the listed land uses.

2.New residential developments subject to the city’s growth management ordinance (Chapter 19.94 SMC).

3.Personal cultivation of cannabis (indoor and outdoor) only allowable in conjunction with residential use subject to SMC 19.50.032.

4.Supportive and transitional housing shall be subject to those restrictions that apply to other residential dwellings of the same type in the same zone.

(Ord. 01-2023 § 1(B), 2023; Ord. 07-2022 § 3(A) (Exh. A(D)), 2022; Ord. 01-2021 § 1(2), 2021; Ord. 04-2019 § 4 (Exh. A(D)), 2019; Ord. 01-2019 § 1 (Exh. A), 2019; Ord. 08-2018 § 2 (Exh. A), 2018; Ord. 07-2018 § 3, 2018; Ord. 05-2018 § 3 (Exh. A), 2018; Ord. 08-2015 § 1, 2015; Ord. 03-2015 § 1, 2015; Ord. 02-2014 § 2(D), 2014).

Commercial cannabis businesses are required to locate outside of the areas delineated with and encompassed by the dash lines in Figures 1 through 4 below:

FIGURE – 1

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FIGURE – 2

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FIGURE – 3

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FIGURE – 4

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(Ord. 04-2019 § 5, 2019).

1Code reviser’s note: The development code document adopted by Ordinance 2003-02 contains a color, foldout map zoning map of the city of Sonoma that is not included in this title. Copies are on file in the office of the city clerk.