Contra Costa County, CA Cannabis Regulations: Buffer Zones (2026)

Section 88-28.410(b)(3) sets two buffer standards that apply on top of the chapter's zoning-district and urban-limit-line rules. First, no commercial cannabis business, whether a retailer, cultivator, manufacturer, tester, or distributor, may locate within one thousand feet of a school providing kindergarten through twelfth-grade instruction, a day care center, a youth center, or a drug treatment center, whether that use sits in the unincorporated county or inside one of Contra Costa's nineteen cities. Second, a storefront retailer must stay at least five hundred feet from any other storefront retailer, again counting facilities located in a city as well as the unincorporated area.

The code is specific about how those distances are measured: the horizontal distance measured in a straight line from nearest property line to nearest property line, not driving distance or distance between building entrances. That measurement rule applies to both the one-thousand-foot buffer and the five-hundred-foot retailer-to-retailer buffer.

These buffers exist alongside, not instead of, the chapter's other siting rules: a cannabis business also cannot sit in a cannabis exclusion (-CE) combining district, and it must generally locate inside the county's urban limit line. A site that clears the buffer distances can still fail on those separate grounds, and a permit applicant must satisfy all of them before the Department of Conservation and Development will approve a Chapter 88-28 land use permit.