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Ag Processing on the Farm


Covered on this page are the county land use requirements for permitting on-farm ag processing operations. Permit Sonoma regulates land use in the unincorporated areas of the county.

See Value Add Products for specifics about state and other permit requirements.

Cost: The zoning permit for a Small Scale Ag Processing operation (defined below) will cost around $600 in fees at Permit Sonoma, plus other associated costs. A use permit for an ag processing operation larger than small scale will cost $15,000 or more.

Land Zoning Districts

Every parcel in the county is defined by a Zoning Code District which is used to categorize how lands are intended to be used such as residential, commercial, resources, etc. To learn more about them, visit Permit Sonoma's Zoning & Parcel Reports.

The zoning districts allowed for Small Scale Ag Processing are:

  • LIA Land Intensive Agriculture 
  • LEA Land Extensive Agriculture 
  • DA Diverse Agriculture
  • RRD Rural & Resource Development (ag, mining, forestry)

NOT included are: 

  • AR Agriculture & Rural
  • RR Rural Residential



Ag Processing: taking the raw product and transforming it into another product such as taking milk and making cheese.  
Processing does not include: Incidental cleaning, grading, packing, polishing, sizing and similar preparation of crops which are grown on the site as these activities are “allowed uses” incidental to the agricultural production. 


Cheese in process

Small-Scale Agricultural Processing

As the name implies, this is for small-scale start-up sized facilities. The intent being that if an operation decides to grow beyond the scope of the zoning permit allowance, they will have an income stream to help offset the cost of the use permit. A few key criteria are:

  • Zoning: LIA, LEA, DA and RRD
  • Minimum parcel size: 2 acres.
  • Maximum building size:
    • Lots of 2 acres to less than 5 acres: 3,000 square feet.
    • Lots 5 acres or greater: 5,000 square feet.
  • Production: At least 70% of the agricultural commodities used in the processing must be grown on-site or on lands owned or leased by the farm operator.
  • This zoning permit does not allow the processing of alcoholic beverages, animal slaughter, meat processing or cannabis (processing with hemp is allowed). A use permit is required for those activities.
  • A Waste Management Plan for storing, handling and disposing of any waste by-products is required. Above ground (pond) discharges must be permitted and comply with applicable regulations of the Regional Water Quality Control Board.
  • Groundwater: The County utilizes a mapping and classification system to indicate general areas of groundwater availability in the County as follows:
    • Class 1 areas are Major Groundwater Basins
    • Class 2 areas are Major Natural Recharge Areas
    • Class 3 areas are Marginal Groundwater Availability Areas 
    • Class 4 areas with Low, or Highly Variable, Water Yield

The review requirements for proving adequate groundwater vary by these classes and more thorough analysis, including possible test wells may be required in the marginal groundwater availability areas. 

For small-scale agricultural processing facilities, the water supply serving a criteria are:

Groundwater Availability Area Criteria
No net increase in water usage Allowed if analysis verifies
Class 1 and 2 groundwater availability areas and outside adopted groundwater management plan areas Allowed
Class 3 (marginal groundwater areas) or in an adopted groundwater management or in plan Allowed with groundwater study*
Class 4 (low or highly variable groundwater yields) Use Permit required with groundwater study

Find your groundwater class on on Permit Sonoma’s ActiveMap.
*Guidelines for Preparing Groundwater Studies for Small-Scale Ag Processing Facilities for projects with Class 3 groundwater availability.

Required Forms

The following are the required forms and detailed guidelines on the Permit Sonoma website:

Email Planner@sonoma-county.org with specific questions about the forms, but the AgOmbuds is available to assist as well.

With much emphasis on local products, this is a great time to venture into the value added business with delicious artisan foods and products that build on your family’s legacy!