Paramount, CA Environmental Rules: Flood Elevation Requirements (2026)

Section 15.32.170(C) of the Paramount Municipal Code sets the elevation rule for all areas of special flood hazards. In an A zone, a structure must be elevated to or above the base flood elevation as determined by the community, and the same standard applies in all other zones. When the structure is complete, the elevation of the lowest floor including basement must be certified by a registered professional engineer or surveyor and verified by the community building inspector. That certification and verification go to the Floodplain Administrator, who is the City Manager under Section 15.32.140. The base flood is the flood with a one percent chance of being equaled or exceeded in any given year.

Nonresidential new construction or substantial improvement must either be elevated the same way or be floodproofed to the recommended elevation so the structure is watertight with walls substantially impermeable to water, with structural components able to resist hydrostatic and hydrodynamic loads and buoyancy, and with a certification by a registered professional engineer or architect. Fully enclosed areas below the lowest floor used solely for parking, building access, or storage must equalize flood forces, either with an engineer's or architect's certification or with a minimum of two openings totaling not less than one square inch for every square foot of enclosed area, with the bottom of all openings no higher than one foot above grade.

AR zones work differently. Because Section 15.32.220 treats the entire incorporated City of Paramount as a developed area, all new construction in AR designated areas must meet the Section 15.32.170 through 15.32.220 standards using the lower of either the AR base flood elevation or the elevation that is three feet above the highest adjacent grade. Improvements, including substantial improvements, to existing structures carry no elevation requirement there. A substantial improvement is work whose cost equals or exceeds 50% of the market value of the structure before construction starts.

The sections read print no separate freeboard figure above the base flood elevation. Section 15.32.130 requires the permit application to show the proposed lowest floor elevation, and Section 15.32.200(B) requires manufactured home chassis in Zone A to be supported at no less than 36 inches above grade if the lowest floor is not at or above the base flood.