Lee's Summit, MO Environmental Rules: Flood Elevation Requirements (2026)

Where base flood elevation data have been provided for a numbered or unnumbered A or AE zone, UDO Sec. 170(B)(1)(a) requires that new construction or substantial improvement of any residential structure, including a manufactured home, have the lowest floor, including basement and all mechanical, electrical, and other utility equipment, elevated to two feet above the base flood elevation. That two-foot freeboard is a foot higher than the National Flood Insurance Program's own one-foot floor, giving Lee's Summit an added buffer against wave action and mapping error.

Non-residential construction faces the identical two-foot elevation standard under Sec. 170(B)(1)(b), with an alternative: a commercial, industrial or other non-residential building may instead be floodproofed below that elevation, provided a registered professional engineer or architect certifies the structure is watertight and can resist hydrostatic and hydrodynamic loads, with certification filed with the Floodplain Administrator. Manufactured homes get their own version of the same two-foot rule in most cases (Sec. 170(C)), and fully enclosed areas below the elevated lowest floor used for parking, access or storage must have flood-vent openings totaling at least one square inch per square foot of enclosed area, with the bottom of every opening no higher than one foot above grade (Sec.

170(B)(1)(c)). Critical facilities such as hospitals, fire stations, police stations and schools are held to a higher standard still: they must be elevated above the 500-year flood level, engineer-certified as watertight below that level, and have access routes above the 500-year flood elevation (Sec. 170(A)(9)). A structure may be remodeled without meeting these elevation standards only if the cumulative value of work over five years stays under 50 percent of the structure's market value; beyond that threshold the whole structure must come up to the two-foot freeboard.