Lee's Summit, MO Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Minimum lowest-floor height
- At least 2 feet above base flood elevation
- Where it applies
- Numbered and unnumbered A zones and AE zones with base flood data
- Non-residential alternative
- Floodproofing certified by a registered engineer or architect
- Enclosure openings
- Two openings, 1 square inch per square foot, bottoms within 1 foot of grade
- Administrator
- City Engineer, serving as Floodplain Administrator
- Maximum fine
- $500 per offense, each day a separate offense
- Improvement trigger
- Work over 50 percent of market value within five calendar years
Summary
In Lee's Summit, new homes and substantial improvements in a mapped A or AE flood zone must have the lowest floor, basement and utility equipment included, at least two feet above the base flood elevation. Commercial buildings meet the same two-foot mark or are floodproofed watertight below it with an engineer's certification. The City Engineer administers the rule, and violations are misdemeanors fined up to $500.
In all areas identified as numbered and unnumbered A zones and AE zones, where base flood elevation data have been provided, as set forth in Section 5.170.A.2., the following provisions are required: a. Residential construction: New construction or substantial-improvement of any residential structures, including manufactured homes, shall have the lowest floor, including basement and all mechanical, electrical, and/or other utility equipment, elevated to at least two feet above the base flood elevation. b. Non-residential construction: New construction or substantial-improvement of any commercial, industrial, or other non-residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated to at least two feet above the base flood elevation or, together with attendant utility and sanitary facilities, be floodproofed so that below the base flood elevation the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 55 | Unified Development Ordinance: Supplement 15).
Full Breakdown
Section 5.170(B)(1) of the Unified Development Ordinance sets the elevation standard for Lee's Summit's floodplain overlay. It covers land in numbered and unnumbered A zones and AE zones on the Jackson County flood insurance rate map dated January 20, 2017, as amended (Section 5.140.A), and it applies where base flood elevation data have been provided. The base flood is the flood with a one percent chance of being equaled or exceeded in any given year.
For residential construction, the lowest floor must sit at least two feet above the base flood elevation. The ordinance defines the lowest floor as the lowest floor of the lowest enclosed area, basement included, and it reaches past the floor itself: all mechanical, electrical, and other utility equipment must be raised to the same height. Manufactured homes carry the same two-foot mark. Under Section 5.170.C, a home in an existing manufactured home park can alternatively sit on a chassis supported by reinforced piers at least 24 inches above grade, anchored against flotation, collapse, and lateral movement.
Commercial, industrial, and other non-residential buildings choose between that two-foot elevation and floodproofing, which means the structure is watertight below the base flood elevation, with a registered professional engineer or architect certifying the design to the Floodplain Administrator. Section 5.200.B bars floodproofing of residential structures unless the Federal Insurance Administration grants an exception.
Fully enclosed areas below the lowest floor that are used solely for parking, building access, or storage must have at least two openings totaling not less than one square inch of net area per square foot of enclosed space, with the bottom of every opening no higher than one foot above grade (Section 5.170.B.1.c).
A floodplain development permit is required for each structure (Section 5.150.A). The application must give the lowest-floor elevation in relation to mean sea level, and the City Engineer, who serves as Floodplain Administrator, records the actual elevation of every new or substantially improved structure. An existing structure can be remodeled or enlarged without meeting the elevation standard only while all work in the last five calendar years stays within 50 percent of its current market value (Section 5.170.A.8).
Violations & Fines
Violating Article 5, Division II, including any condition attached to a variance, is a misdemeanor under Section 5.250. A conviction carries a fine of not more than $500.00 plus all costs and expenses of the case, and each day the violation continues counts as a separate offense. The City can also seek injunctive relief through civil remedies against development in the FW and FF overlay districts done without approved permits.
Frequently Asked Questions
How high must a new house in a Lee's Summit flood zone be built?
Can a commercial building be floodproofed instead of elevated?
Do additions and remodels have to meet the elevation rule?
What are the rules for a garage or storage area below the lowest floor?
How does a property owner ask for a variance or appeal a denial?
Sources & Official References
Other rules in Lee's Summit
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Flood Elevation Requirements in Nearby Cities
How other cities in Jackson County handle flood elevation requirements.