Solano County Unincorporated Zoning Intelligence

Exclusive Agricultural (A-160 through A-20) zoning strongly discourages conversion. These districts carry minimum parcel sizes tied to the zone number (e.g., A-160 implies 160-acre minimums) and are subject to Williamson Act contracts on many parcels, which provide property tax reductions in exchange for 10-year rolling agricultural commitments. Conversion requires a general plan amendment, zone change, and often a Williamson Act cancellation - a lengthy and uncertain process.

The MGV Specific Plan covers portions of the Suisun Valley wine-growing region and breaks land into sub-districts including Agriculture Preserve, Rural Farm, Rural Meadow, Rural Neighborhood, Rural Mixed-Use Center, and Open Lands designations. Each sub-district has a distinct permitted-use table and development standard. Landowners within the plan area should consult the specific plan document before assuming standard county zoning rules apply.

The largest industrial concentration is in General Manufacturing (MG-3 at nearly 1,893 acres), used for heavier manufacturing and processing. Industrial-Agricultural Service (I-AS, 504 acres) is oriented toward farm-support businesses. Water Dependent Industrial (IWD, 278 acres) is reserved for port and water-access operations. These districts are geographically limited and surrounded by agricultural land, so access and infrastructure should be confirmed early in feasibility.

The Suisun Marsh Agricultural and Suisun Valley Agriculture zones (roughly 25,000 acres combined) are subject to both the county zoning code and the Suisun Marsh Preservation Act, a state-level program requiring coordinated permits. Wetland mitigation, water quality, and hunting-club uses are common policy concerns. Any development or land-use change in these areas typically requires coordination with the Bay Conservation and Development Commission.

Residential uses are limited outside of the Middle Green Valley Specific Plan and a small number of rural residential parcels. The General Agriculture districts do allow one dwelling per existing parcel as an accessory use to farming, and state ADU law provides some additional flexibility. Large-scale residential subdivision would require a general plan amendment and is unlikely to gain approval given the county's long-standing agricultural preservation policies.