Chino Hills, CA Environmental Rules: Flood Elevation Requirements (2026)

170 of the Floodplain Damage Prevention and Floodplain Management chapter sets the construction standards that apply to every new building and substantial improvement inside a mapped special flood hazard area in Chino Hills. 1 requires the lowest floor, including any basement, to be elevated to at least one foot above the base flood elevation, the 100-year flood level shown on the FEMA Flood Insurance Rate Map; that one-foot freeboard sits on top of FEMA's federal minimum. Once the structure is complete, a registered civil engineer or surveyor must certify the as-built lowest-floor elevation, or the city's Building Official must verify it, and that certification goes to the Floodplain Administrator, the City Engineer, before the project can close out.

3 instead of elevating. The same section requires flood-resistant construction materials, utility equipment located to keep water out during flooding, and, for any enclosed area below the lowest floor used only for parking or storage, engineered flood openings sized to at least one square inch of net open area per square foot of enclosed space so hydrostatic pressure can equalize automatically. 200.