City of Sikeston, MO Article V Provisions For Flood Hazard Reduction

Section 410.160 General Standards.

[Ord. No. 6322, 11-27-2023]

A. No permit for floodplain development shall be granted for new construction, substantial improvements, and other improvements, including the placement of manufactured homes, within any numbered or unnumbered A Zones, AE, AO, and AH Zones, unless the conditions of this Section are satisfied.

1. All new construction, subdivision proposals, substantial improvements, prefabricated structures, placement of manufactured homes, and other developments shall require:

a. All new construction, including manufactured homes and substantial improvements, shall be designed (or modified) and adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

b. All new construction and substantial improvements shall be constructed with materials resistant to flood damage.

c. All new construction and substantial improvements shall be constructed by methods and practices that minimize flood damages.

d. All new construction and substantial improvements shall be constructed with electrical, heating, ventilating, plumbing and air-conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

e. All new and replacement water supply systems be designed to minimize or eliminate infiltration of floodwaters into the system.

f. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwater into the systems and discharges from the systems into floodwaters. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

g. All areas identified as unnumbered A Zones on the FIRM are subject to inundation of the one percent (1%) annual chance (aka "100-year") flood; however, the base flood elevation is not provided. Development within unnumbered A Zones is subject to all provisions of this Chapter. If Flood Insurance Study data is not available, the community shall obtain, review, and reasonably utilize any base flood elevation or floodway data currently available from Federal, State, or other sources.

h. Until a floodway has been designated, no new construction, substantial improvements, including fill, may be permitted within any unnumbered or numbered A Zones, or AE Zones on the City's FIRM unless the applicant for the land use has demonstrated that the proposed use, when combined with all other existing and reasonably anticipated development, will not increase the water surface elevation of the 100-year flood more than one (1) foot on the average cross section of the reach in which the development or landfill is located as shown on the Flood Insurance Rate Study.

2. Storage, Material, And Equipment.

a. The storage or processing of materials that are, in time of flooding, buoyant, flammable, explosive or could be injurious to human, animal or plant life is prohibited.

b. Storage of other material or equipment may be allowed if not subject to major damage by floods and firmly anchored to prevent flotation or if readily removable from the area within the time available after flood warning.

3. Accessory Structures.

a. Structures used solely for parking and limited storage purposes, not attached to any other structure on the site, of limited investment value, and not larger than four hundred (400) square feet, may be constructed at-grade and wet-floodproofed, provided there is no human habitation or occupancy of the structure; the structure is of single-wall design; the accessory structure meets the following floodplain management requirements; and a floodplain development permit has been issued. Wet-floodproofing is only allowed for small low-cost structures.

4. Agricultural Structures.

a. Structures used solely for agricultural purposes in connection with the production, harvesting, storage, drying, or raising of agricultural commodities, including the raising of livestock, may be constructed at-grade and wet-floodproofed, provided there is no human habitation or occupancy of the structure; the structure is of single-wall design; there is no permanent retail, wholesale, or manufacturing use included in the structure; the structure meets the following floodplain management requirements; and a floodplain development permit has been issued.

Section 410.170 Standards For Subdivision Proposals.

[Ord. No. 6322, 11-27-2023]

A. All subdivision proposals and other proposed new developments, including manufactured home parks or subdivisions, shall be consistent with the need to minimize flood damage.

B. All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.

C. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood hazards.

D. All proposals for development, including proposals for manufactured home park and subdivisions greater than either fifty (50) lots or five (5) acres, whichever is lesser, include within such proposals base flood elevation data.

Section 410.180 Specific Standards.

[Ord. No. 6322, 11-27-2023]

A. In all areas identified as numbered and unnumbered A Zones, AE, and AH Zones, where base flood elevation data has been provided as set forth in Article IV, Section 410.140, the following provisions are required:

1. Residential Construction. New construction or substantial improvement of any residential structure, including manufactured homes, shall have the lowest floor, including basement, elevated one (1) foot above the base flood elevation. The elevation of the lowest floor shall be certified by a Missouri licensed land surveyor, engineer, or architect.

2. Non-Residential Construction. New construction or substantial improvement of any commercial, industrial or other non-residential structure, including manufactured homes, shall either have the lowest floor, including basement, elevated to at least one (1) foot above the level of the base flood elevation or, together with attendant utility and sanitary facilities, be floodproofed so that below such a level the structure is water-tight 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. A Missouri registered professional engineer or architect shall certify that the standards of this Subsection are satisfied. Such certification shall be provided to the official as set forth in Article IV, Section 410.140(A)(6).

3. Enclosures Below Lowest Floor. Require for all new construction and substantial improvement that fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a Missouri registered professional engineer or architect or meet or exceed the flowing minimum criteria:

a. A minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding shall be provided.

b. The bottom of all openings shall be no higher than one (1) foot above grade. Openings may be equipped with screens, louvers, valves or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

Section 410.190 Manufactured Homes.

[Ord. No. 6322, 11-27-2023]

A. All manufactured homes to be placed within all unnumbered and numbered A Zones, AE, and AH Zones, on the community's FIRM shall be required to be installed using methods and practices that minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse or lateral movement. Manufactured homes must be anchored in accordance with State and local building codes and FEMA guidelines. In the event that over-the-top frame ties to ground anchors are used, the following specific requirements (or their equivalent) shall be met:

1. Over-the-top ties shall be provided at each of the four (4) corners of the manufactured home with two (2) additional ties per side at intermediate locations and manufactured homes less than fifty (50) feet long requiring only one (1) additional tie per side;

2. Frame ties shall be provided at each corner of the manufactured home with five (5) additional ties per side at intermediate points and manufactured homes less than fifty (50) feet long requiring only four (4) additional ties per side;

3. All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds; and

4. Any additions to the manufactured home be similarly anchored.

B. Require that all manufactured homes to be placed within or substantially improved within unnumbered or numbered A Zones, AE, and AH Zones, on the community's FIRM on-site:

1. Outside of manufactured home park or subdivision;

2. In a new manufactured home park or subdivision;

3. In an expansion to and existing manufactured home park or subdivision; or

4. In an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as the result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is one (1) foot above the base flood elevations and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement in accordance with the provisions of this Section. The elevation of the lowest floor shall be certified by a Missouri licensed land surveyor, engineer, or architect.

C. Require that manufactured homes to be placed or substantially improve on sites in an existing manufactured home park or subdivision within all unnumbered and numbered A Zones, AE and AH Zones, on the community's FIRM, that are not subject to the provisions of Article V, Section 410.190(B) of this Chapter, be elevated so that either:

1. The lowest floor of the manufactured home is at one (1) foot above the base flood level; or

2. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade, and be securely attached to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

D. Require that recreational vehicles placed on sites within all unnumbered and numbered A Zones, AO, AE and AH Zones on the community's FIRM either:

1. Be on a site for fewer than one hundred eighty (180) consecutive days; or

2. Be fully licensed and ready for highway use;* or

3. Meet the permitting, elevation and anchoring requirements for manufactured homes of this Chapter.

*A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect-type utilities and security devices and has no permanently attached additions.

Section 410.200 Areas Of Shallow Flooding (AO And AH Zones).

[Ord. No. 6322, 11-27-2023]

A. Located within the areas of special flood hazard established in Article III, Section 410.060, are areas designated as AO Zones. These areas have special flood hazards associated with base flood depths of one (1) foot to three (3) feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and intermediate; therefore, the following provisions apply:

1. AO Zones.

a. All new construction and substantial improvements of residential structures, including manufactured homes, shall have the lowest floor (including basement) elevated above the highest adjacent grade at least one (1) foot above depth number specified in feet on the community's FIRM [at least two (2) feet plus one (1) foot of freeboard if no depth number is specified].

b. All new construction and substantial improvements of non-residential structures, including manufactured homes, shall:

(1) Have the lowest floor (including basement) elevated above the highest adjacent grade at least one (1) foot above feet above the depth number specified in feet on the community's FIRM [at least two (2) feet plus one (1) foot of freeboard if no number is specified]; or

(2) Together with attendant utility and sanitary facilities be completely floodproofed to or above the level so that any space below that level is water-tight 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.

c. Adequate drainage paths around structures on slopes shall be required in order to guide floodwaters around and away from proposed structures.

d. The anchoring requirements for manufactured homes established in Article V, Section 410.190, shall be required.

2. AH Zones.

a. The specific standards for all areas of special flood hazard where base flood elevation data has been provided shall be required as set forth in Article V, Section 410.180.

b. Adequate drainage paths around structures on slopes shall be required in order to guide floodwaters around and away from proposed structures.

3. Floodway. Located within areas of special flood hazard established in Article III, Section 410.060, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris and potential projectiles, the following provisions shall apply:

a. The community shall select and adopt a regulatory floodway based on the principle that the area chosen for the regulatory floodway must be designed to carry the waters of the base flood without increasing the water surface elevation of that flood more than one (1) foot at any point.

b. The community shall prohibit any encroachments, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.

c. A community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the community first applies for a conditional FIRM and floodway revision, fulfills the requirements of such revisions as established under the provisions of 44 CFR 65.12, and receives the approval of FEMA.

d. If Article V, Section 410.200(A)(3)(b), is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Article V.

e. In unnumbered A Zones, the community shall obtain, review, and reasonably utilize any base flood elevation or floodway data currently available from Federal, State, or other sources as set forth in Article V, Section 410.160(A)(1)(g).