Chula Vista, CA Environmental Rules: Flood Elevation Requirements (2026)

100 as the water surface level of a watercourse or waterbody, referenced to an established datum, corresponding to a flood with a one percent chance of being equaled or exceeded in any given year (the 100-year flood). 150 requires the lowest floor elevation, including any basement, of new residential construction and substantial improvements to be elevated a minimum of one foot above the regulatory flood elevation, except that in Zone AO the lowest floor must be as high as the depth number shown on the effective FIRM above the highest adjacent grade, or two feet if no depth number is specified.

160 applies the same one-foot standard to nonresidential structures, with an alternative: instead of elevating, a nonresidential building may be completely floodproofed to or above the regulatory flood elevation so that any space below is watertight, with walls substantially impermeable to water and structural components able to resist hydrostatic and hydrodynamic loads. 120(A)(2) requires the permit application to include the lowest-floor elevation (or floodproofed elevation) and certification from a licensed civil engineer, structural engineer, or architect that the plans comply with National Flood Insurance Program floodproofing requirements.

170: their floor may sit below the BFE only if built with flood-resistant materials below that line, anchored against flotation, and fitted with openings sized to let floodwater automatically enter and exit.