Garden Grove, CA Environmental Rules: Flood Zones (2026)

040 is Garden Grove's floodplain management ordinance, adopted under the authority the state Legislature granted cities in Government Code Sections 65302, 65560, and 65800. It applies to every area of special flood hazard within city limits, using FEMA's February 18, 2004 Flood Insurance Study, Flood Insurance Rate Maps, and Flood Boundary and Floodway Maps, plus any later amendments, as the map that defines where the overlay applies; those documents are kept on file at 11222 Acacia Parkway. 040(B) requires a development permit from the Floodplain Administrator, a role the City Manager or a designee fills.

An application has to include a site plan with spot ground elevations at building corners, the proposed location of water supply and sewer connections, the base flood elevation if known, foundation design details showing the lowest floor elevation relative to mean sea level, and, for a crawl-space foundation, the size of any flood vents required under FEMA Technical Bulletins 1-93 and 7-93. Fill placed under a foundation must be compacted to 95% under the Standard Proctor Test method. 040(A)(7) makes clear that wherever this overlay conflicts with another ordinance, easement, or deed restriction, whichever rule is more restrictive controls.

Because the Flood Hazard Overlay applies across every base zone, from R-1 single-family lots to the Mixed Use corridor along Garden Grove Boulevard, a property owner has to check the FIRM designation for a specific parcel before assuming standard zone setbacks and standards are the only thing that applies to a proposed project.