Simi Valley, CA Environmental Rules: Flood Elevation Requirements (2026)

201 as the water surface elevation on the Flood Insurance Rate Map for Zones AE, AH, A1-30, VE and V1-V30 corresponding to a flood with a one percent or greater annual chance of occurring, the standard 100-year flood. The chapter also defines Freeboard as a margin of safety added on top of the BFE to cover waves, debris, measurement error, missing data, or a changing climate. 603(d)(2) requires new construction and substantial improvements of residential structures to have their lowest floor elevated at least one foot above the BFE in AE and AH zones.

In an AO zone, the lowest floor must sit at least one foot above the depth number printed on the FIRM, or two feet above the highest adjacent grade if no depth number is shown. 402(c). 603 must either meet the same elevation standard or be floodproofed and certified watertight by a registered engineer or architect. Enclosed areas below the lowest floor, such as an attached garage built below the BFE, must use flood-resistant materials and automatic flood-equalizing openings, and any enclosure over five feet high requires a recorded non-conversion agreement barring its use as living space. The Floodplain Administrator enforces these standards and reviews building permit applications for compliance before construction begins.