Casa Grande, AZ Environmental Rules: Flood Zones (2026)

The City of Casa Grande designates special flood hazard areas (SFHAs) under Section 15.40.580 of the Municipal Code, and Section 15.40.730 makes it unlawful to engage in any development within an SFHA without first securing a SFHA development permit from the floodplain administrator. The permit must be obtained before construction or development begins, including placement of manufactured homes. Applications go on forms furnished by the floodplain administrator and must show, at minimum: the proposed elevation of the lowest floor in relation to mean sea level (and, in Zone AO, the existing highest adjacent natural grade); the elevation to which any nonresidential structure will be floodproofed; engineer or architect certification that floodproofing methods meet the chapter's criteria; base flood elevation data; and a description of any watercourse alteration or relocation.

Design procedures and criteria must follow those prepared and published by the City of Casa Grande. If the floodplain administrator cannot resolve a violation through standard enforcement, Section 15.40.710 requires a report to the floodplain board, which within thirty days must either order abatement, refer the matter to the floodplain review board for a variance determination under Article VII, or order the property owner to supply additional information. The board can also, where applicable, ask FEMA to deny flood insurance on a noncompliant property under Section 1316 of the National Flood Insurance Act. Violating the permit requirement itself is a Class 2 misdemeanor under Section 15.40.705.B, with each day of continuing violation treated as a separate offense.