Anaheim, CA Environmental Rules: Flood Zones (2026)

28 of the Anaheim Municipal Code governs flood hazard reduction citywide. 050, which draws on FEMA's Flood Insurance Rate Map (FIRM). The permit application must include duplicate scaled plans showing elevation, drainage facilities, and existing or proposed structures, and the applicant must submit engineer- or architect-certified data: proposed lowest-floor elevation relative to mean sea level, floodproofing elevation for nonresidential structures, drainage studies, and grading plans with finished-grade elevations. 090. 120, reviewing every permit for compliance. 130 require new construction and substantial improvements to be anchored against flotation and lateral movement, built with flood-resistant materials, and to have the lowest floor (including any basement) elevated at least one foot above the base flood elevation, certified by a registered engineer or surveyor before final inspection.

In Zone AO, the lowest floor must clear the highest adjacent grade by the FIRM depth number plus one foot, or three feet if no depth number is listed. Nonresidential buildings may floodproof instead, with watertight walls and structural components rated for hydrostatic and hydrodynamic loads, certified by a licensed engineer or architect. Enclosed areas below the lowest floor used only for parking, access, or storage must have flood-vent openings totaling at least one square inch per square foot of enclosed area, with openings no higher than one foot above grade. 140.