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PJR-078 Major Subdivision

Permit and Resource Management Department Banner 750

Revised 05/22/2010

Identifies the information and materials required for a Major Subdivision application and to provide an overview of the procedure for processing these applications. A major subdivision is a division of land into five (5) or more parcels. Major subdivisions are governed by the Subdivision Map Act. (California Government Code, Section 66410, et. seq.), the Sonoma County Subdivision Ordinance - Sonoma County Code, Chapter 25, the Sonoma County Zoning Code -(County Code, Chapter 26 and the Sonoma County General Plan.


After a complete application is submitted, a project planner in the Project Review Division of the Permit Sonoma is assigned to the project. Project applications are sent on referral to various Permit Sonoma divisions, County departments, and State agencies for review, comment and recommended conditions. Based on those responses and staff review, additional information or studies may be required. Environmental review under the California Environmental Quality Act (CEQA) is required for major subdivisions. The project planner will prepare an initial study using CEQA guidelines. This is an assessment of potential environmental impacts and identification of mitigation measures to reduce potential impacts to an insignificant level. If the project planner determines that no significant environmental impact will result from the proposed subdivision, a Negative Declaration or Mitigated Negative Declaration will be prepared.

After the environmental review is completed, the Project Review Advisory Committee (PRAC) will recommend conditions for the Planning Commission. Thereafter, the proposed major subdivision will be scheduled for a public hearing before the Planning Commission. A notice of the public hearing is published in a newspaper of general distribution, posted on the property and mailed to owners of properties within 300 feet of the site. A copy of the staff report and recommended conditions is mailed to the applicant prior to the hearing date. All interested persons are given an opportunity to comment on the proposed major subdivision at the public hearing. If the project is approved by the Planning Commission, there is a ten (10) day appeal period to the Board of Supervisors.

After final approval, the applicant has 24 months to comply with the conditions of approval and record the final map. The applicant may apply for a one (1) year extension of time prior to the expiration of this 24 month period. A maximum of five (5) one year extensions of time are allowable. The Planning Commission must approve each extension request. 

Required Application Materials

A complete application must include all of the following:

  1. Applications:Planning Application form PJR-001(PDF), signed by all property owners, Major Subdivision Supplemental Information form PJR-079 (PDF), and Indemnification Agreement form PJR-011, (PDF) signed by the applicant.
  2. Maps. Provide 15 full-sized copies of the tentative map (24 in. x 36 in. minimum) prepared by a registered civil engineer or a licensed land surveyor. This map must comply with all tentative map requirements on page two. Provide one (1) legible reduced copy of the tentative map (8 ½ in. x 11 in.).
  3. Sewage disposal. A minimum of one acceptable percolation test hole per parcel and one acceptable soil profile per five parcels is required if on-site wastewater disposal is proposed. If sanitary sewer service is available, a letter shall be submitted from the sewer provider stating the ability of the system to handle sewage from the proposed subdivision and that the development can connect to the system.
  4. Water Supply. If water is by public utility or private water company, a letter from the water provider shall be submitted stating its ability to serve the subdivision. If water is by wells or springs, sufficient evidence shall be submitted that an adequate quantity of potable water can be obtained from wells or springs for the lots in the subdivision. Special requirements apply in water scarce areas.
  5. Deeds. Provide a current copy of the recorded deed(s) to the property to be subdivided (available at the County Recorder’s Office.)
  6. Assessor’s Parcel Map. Provide a current Assessor’s Parcel Map with the subject property highlighted (available at the County Assessor's Office).
  7. USGS Map. A copy of the USGS quad map (8 ½ in. x 11 in.) with the site identified. Maps may be obtained from Permit Sonoma.
  8. Fire Safe and Vegetation Management Plan. Provide plan as described on page three.
  9. Stormwater Management Submittals. Provide description of stormwater management including runoff, treatment, drainage, and flood control. If applicable, provide location of existing wetlands and measures to avoid. An alternative analysis should be required demonstrating why the wetlands cannot be avoided.

Filing Fee

See the current Permit Sonoma Project Review Fee Schedule.

Tentative Map Requirements

Every tentative map shall be clearly and legibly drawn to scale and shall contain the following information:

  1. A site location map indicating the location of the proposed subdivision in relation to the surrounding area or region.
  2. The tract name, if any, date, north point, scale, and sufficient description to define the location and boundaries of the proposed tract.
  3. Names and addresses of applicant, property owner of record, and engineer or surveyor.
  4. Location, names and present width of adjacent or abutting roads, streets, highways and ways, and their status as public or private roads.
  5. The locations, names, widths and approximate gradient of all roads, streets, highways, and ways in or adjacent to the proposed subdivision or to be offered for dedication.
  6. The location and width of all proposed or existing easements for drainage, sewerage, public utilities and roads.
  7. Sufficient contours to determine the general slope of the land and the high and low points thereof.
  8. The approximate dimensions of all lots and radii of all curves.
  9. Total acreage of site (gross and net), total number of lots, minimum lot size, average lot size, lot numbers.
  10. The location and identification of all existing structures on the property, including distances to existing and proposed property lines. 

Fire Safe & Vegetation Management Planning Guidelines

A Fire Safe & Vegetation Management Plan, acceptable to the Sonoma County Department of Emergency Services (DES), is required with every application for a subdivision. To assist in the preparation of the Fire Safe & Vegetation Management Plan, one can refer to the Fire Safe Standards and Vegetation Management Planning Requirements from the DES website at

The purpose of the Fire Safe & Vegetation Management Plan is to recognize potential fire hazards and to establish mitigation to minimize those hazards. The Fire Safe & Vegetation Management Plan may be prepared by the applicant and/or a qualified professional depending on the complexity of the project. DES can be contacted to coordinate requirements.

The Fire Safe & Vegetation Management Plan must address the following items of concern:

  1. Terrain: Are there steep slopes, deep canyons, loose soil, rugged terrain, or other physical obstacles that may impact wild land fire safety?
  2. Vegetation: Describe the vegetation in the vicinity of the building site and also the area. Is it primarily grass, chaparral, heavy/tall brush, sparse trees, and/or heavily wooded? In extreme urban-wild land interface or other high wild land fire hazard area, measures in addition to vegetation management may be required to reduce fire hazards.
  3. Access to Property: Do the ingress/egress roads meet minimum Fire Safe Standards for grade, width, and turnouts? Is the access road wide enough for a fire apparatus and other emergency equipment? Are there at least two different ingress-egress routes to the building sites?
  4. Building Sites: Are building sites situated so as to provide adequate space for the establishment of required defensible space without property line conflicts? In high fire hazard areas, 150 feet of defensible space may be required or prudent. Will proposed structures or building site be located in areas less affected by wild land fire (i.e. away from mid-slope locations, ridgetops, etc.)?
  5. Fire Services: Who will provide fire services? What is the travel/response time and distance from the proposed subdivision from this service or from other fire services in the area?
  6. Fire Protection Water Supply: Is there a public water supply system? Does it provide minimum required fire flow? What is the maximum permitted fire hydrant spacing and location? If water tanks are used, can they be cited for gravity flow rather than requiring power for operation? What is the proposed water source
    (e.g. municipal system, well, spring, creek pond, etc?) Is it on or close to the site? What is the estimated water volume? Is the water supply source reliable year round?
  7. Building Construction: Will structural “fire hardening” techniques be utilized in the design of the proposed building?

The items of concern above should be viewed as the minimum that need to be addressed for Fire Safe & Vegetation Management Plans. The Sonoma County Fire Marshal acknowledges that some of these items of concern may not apply to a given proposed subdivision. Conversely, many high fire hazard areas may have high to extreme wild land fire hazards such that additional measures may be necessary to reduce fire hazards. DES may be contacted for questions regarding the preparation of the Fire Safe & Vegetation Management Plan. On-site fire hazard assessments can be scheduled with the Sonoma County Fire Marshal at  (707) 565-2361.