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File #: 2025-0859   
Type: Regular Calendar Item Status: Agenda Ready
File created: 7/23/2025 In control: Permit and Resource Management
On agenda: 8/26/2025 Final action:
Title: 1:45 P.M. - Zone Change to remove the Z (ADU Exclusion) Combining District; 3643 Middle Two Rock Road, Petaluma (Permit Sonoma File No. ZCE21-0002).
Department or Agency Name(s): Permit and Resource Management
Attachments: 1. Summary Report.pdf, 2. ZCE21-0002 Att 1 Board of Supervisors Ordinance.pdf, 3. ZCE21-0002 Board of Supervisors Ordinance Exhibit.pdf, 4. ZCE21-0002 Att 2 Planning Commission Staff Report.pdf, 5. ZCE21-0002 Att 3 Planning Commission Actions Resolution.pdf, 6. ZCE21-0002 Att 4 Site Plan.pdf, 7. ZCE21-0002 Att 5 General Plan Land Use Map.pdf, 8. ZCE21-0002 Att 6 Vicinity Map.pdf, 9. ZCE21-0002 Att 7 Zoning Map.pdf, 10. ZCE21-0002 Att 8 Powerpoint.pdf

To: The Board of Supervisors of Sonoma County

Department or Agency Name(s): Permit Sonoma

Staff Name and Phone Number: Levan King Cranston (707) 565-2592

Vote Requirement: Majority

Supervisorial District(s): Second

 

Title:

Title

1:45 P.M. - Zone Change to remove the Z (ADU Exclusion) Combining District; 3643 Middle Two Rock Road, Petaluma (Permit Sonoma File No. ZCE21-0002).

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Recommended Action:

Recommended action

Permit Sonoma recommends that the Board of Supervisors conduct a public hearing and adopt an Ordinance finding the proposed project exempt from the California Environmental Quality Act under CEQA Guidelines Section 15305 (minor alterations in land use limitations) and California Public Resources Code Section 21080.17 and approving a zone change to remove the Z (Accessory Dwelling Unit Exclusion) Combining District from the subject parcel at 3643 Middle Two Rock Road, Petaluma; APN 022-220-021 (Permit Sonoma File No. ZCE21-0002). (Second District)

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Executive Summary:

The project proposes approval of a Zone Change to remove the Z (Accessory Dwelling Unit Exclusion) Combining District on a 76.73-acre parcel zoned Land Extensive Agriculture (LEA), located at 3643 Middle Two Rock Road, Petaluma, approximately 3.5 miles west of the City of Petaluma. The subject parcel is developed with a single-family residence, with the majority of the property maintained as pastureland. The request would allow for an Accessory Dwelling Unit (ADU) to be developed on the subject property in the future.

 

The Planning Commission adopted Resolution No. 23-34 on June 29, 2023, which recommended your Board approve the Zone Change to remove the Z Combining District from the subject parcel.

 

Discussion:

The Z combining district was applied to the subject property during the implementation of the 1989 General Plan, when many properties formerly designated “AE” Agriculture Exclusive were re-designated Land Extensive Agriculture (LEA) and zoned LEA Z. The purpose of Sec. 26-76-005 of the Sonoma County Zoning Code (Z - Accessory Dwelling Unit Exclusion Combining District) is to provide for the exclusion of accessory dwelling units in specific areas of Sonoma County. This includes areas where there is an inadequate supply of water for drinking or firefighting, where there is inadequate sewer services or danger of groundwater contamination, where the addition of accessory dwelling units would contribute to existing traffic hazards or increase the burden on heavily impacted streets, roads or highways, and where, because of topography, access or vegetation, there is a significant fire hazard.

 

In 2019, the Board adopted Ordinance No. 6285, which removed the “Z” Accessory Dwelling Unit Exclusion Combining District from 1,924 specified parcels located in the LIA - Land Intensive Agriculture, LEA - Land Extensive Agriculture, and DA - Diverse Agriculture zoning districts countywide that met screening criteria related to fire hazard zones, biotic habitat, groundwater, traffic, and Land Conservation Contracts. Parcels in waiver prohibition areas were not included in the countywide legislative proposal due to the differing site-specific environmental and regulatory constraints in the various waiver prohibition areas. Parcels in waiver prohibition areas would continue to be considered on a case-by-case basis. Most waiver prohibition areas are characterized by clusters of small parcels without the ability to provide adequate setbacks for septic systems to neighboring wells.

 

The subject parcel does not meet the criteria for inclusion in the Z Accessory Dwelling Unit Exclusion District per Article 76 of the Sonoma County Code. The subject parcel is approximately 76.73-acres in size, and therefore has adequate space to provide separation between septic systems and neighboring wells.

 

The Planning Commission voted 5-0 on June 29, 2023, adopting Resolution No. 23-34 finding the project exempt from CEQA and recommending approval to the Board of Supervisors for the requested zone change to remove the Z Combining District. The project is categorically exempt under State CEQA Guidelines Section 15305 because removing the Z Combining District is a minor alteration in land use limitations in an area with an average slope of less than 20% that does not result in any changes in land use or density because under state law the addition of one accessory dwelling unit may not be considered to exceed the allowable density (Government Code § 65852.2(a)(8)). Adoption of the proposed ordinance is also exempt from CEQA pursuant to Public Resources Code section 21080.17, adoption of an ordinance by a city or county to implement the provisions of Government Code section 65852.2, regarding permitting of accessory dwelling units.

 

Strategic Plan:

Not Applicable

Racial Equity:

 

Was this item identified as an opportunity to apply the Racial Equity Toolkit?

No

 

Prior Board Actions:

Not Applicable

 

Fiscal Summary

 

Narrative Explanation of Fiscal Impacts:

This is an at-cost project for which project costs are the responsibility of the applicant.

 

Narrative Explanation of Staffing Impacts (If Required):

Not Applicable

 

Attachments:

Attachment 1 ZCE21-0002 Board of Supervisors Ordinance

Attachment 2 ZCE21-0002 Planning Commission Staff Report

Attachment 3 ZCE21-0002 Planning Commission Resolution No. 23-34

Attachment 4 ZCE21-0002 Site Plan

Attachment 5 ZCE21-0002 General Plan Land Use Map

Attachment 6 ZCE21-0002 Vicinity Map

Attachment 7 ZCE21-0002 Zoning Map

Attachment 8 ZCE21-0002 PowerPoint Presentation

 

Related Items “On File” with the Clerk of the Board:

Not Applicable