A.Â
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.
B.Â
All areas identified as unnumbered A Zones on the FIRM are subject
to inundation of the one-percent-chance (aka one-hundred-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.
C.Â
Until a floodway is designated, no new construction, substantial
improvements or other development, including fill, shall be permitted
within any unnumbered or numbered A Zones or AE Zones on the community's
FIRM, unless it is demonstrated that the cumulative effect of the
proposed development, when combined with all other existing and anticipated
development, will not increase the water surface elevation of the
base flood more than one (1) foot at any point within the community.
D.Â
All new construction, subdivision proposals, substantial improvements,
prefabricated structures, placement of manufactured homes and other
developments shall require:
1.Â
Design or adequate anchorage to prevent flotation, collapse
or lateral movement of the structure resulting from hydrodynamic and
hydrostatic loads, including the effects of buoyancy;
2.Â
Construction with materials resistant to flood damage;
3.Â
Utilization of methods and practices that minimize flood damages;
4.Â
All electrical, heating, ventilation, plumbing, air-conditioning
equipment and other service facilities be designed and/or located
so as to prevent water from entering or accumulating within the components
during conditions of flooding;
5.Â
New or replacement water supply systems and/or sanitary sewage
systems be designed to minimize or eliminate infiltration of floodwaters
into the systems and discharges from the systems into floodwaters
and on-site waste disposal systems be located so as to avoid impairment
or contamination; and
6.Â
Subdivision proposals and other proposed new development, including
manufactured home parks or subdivisions, located within special flood
hazard areas are required to assure that:
a.Â
All such proposals are consistent with the need to minimize
flood damage;
b.Â
All public utilities and facilities, such as sewer, gas, electrical
and water systems, are located and constructed to minimize or eliminate
flood damage;
c.Â
Adequate drainage is provided so as to reduce exposure to flood
hazards; and
d.Â
All proposals for development, including proposals for manufactured
home parks and subdivisions, greater than fifty (50) lots or five
(5) acres, whichever is lesser, include within such proposals base
flood elevation data.
E.Â
Storage, Material And Equipment.
1.Â
The storage or processing of materials within the special flood
hazard area that are in time of flooding buoyant, flammable, explosive
or could be injurious to human, animal or plant life is prohibited.
2.Â
Storage of other material or equipment may be allowed if not
subject to major damage by floods, if firmly anchored to prevent flotation
or if readily removable from the area within the time available after
a flood warning.
A.Â
In all areas identified as numbered and unnumbered A Zones, AE and AH Zones, where base flood elevation data have been provided, as set forth in Article IV, Section 415.150(B), the following provisions are required:
1.Â
Residential Construction. New construction or substantial improvement
of any residential structures, including manufactured homes, shall
have the lowest floor, including basement, elevated to one (1) foot
above base flood elevation. The elevation of the lowest floor shall
be certified by a Missouri-licensed land surveyor, engineer, or architect.
2.Â
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 one (1) foot 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. A Missouri-registered professional engineer or architect shall certify that the standards of this Subsection are satisfied. Such certification shall be provided to the Floodplain Administrator as set forth in Article III, Section 415.130(A)(7), (8) and (9).
3.Â
Enclosures Below Lowest Floor. Require, for all new construction
and substantial improvements, that fully enclosed areas below the
lowest floor used solely for parking of vehicles, building access
or storage in an area other than a basement and that are subject to
flooding shall be designed to automatically equalize hydrostatic flood
forces on exterior walls by allowing for the 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 following minimum criteria:
a.Â
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; and
b.Â
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.
A.Â
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. Methods
of anchoring may include, but are not limited to, use of over-the-top
or frame ties to ground anchors.
B.Â
Require manufactured homes that are placed or substantially improved
within unnumbered or numbered A Zones, AE and AH Zones on the community's
FIRM on sites outside of manufactured home park or subdivision; in
a new manufactured home park or subdivision; in an expansion to an
existing manufactured home park or subdivision; or 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 elevated to one (1) foot above the base flood elevation and
be securely attached to an adequately anchored foundation system to
resist flotation, collapse and lateral movement. The elevation of
the lowest floor shall be certified by a Missouri-licensed land surveyor,
engineer, or architect.
C.Â
Require that manufactured homes to be placed or substantially improved 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 IV, Section 415.170, of this Chapter, be elevated so that either:
1.Â
The lowest floor of the manufactured home is at one (1) foot
above the base flood level; or
2.Â
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, plus
one (1) foot of freeboard, and be securely attached to an adequately
anchored foundation system to resist flotation, collapse and lateral
movement.
A.Â
Located within the areas of special flood hazard as described in Article II, Section 415.040, 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 indeterminate. The following provisions apply:
1.Â
AO Zones.
a.Â
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 the depth number specified in feet on the community's
FIRM [at least two (2) feet plus feet/foot of freeboard if no depth
number is specified].
b.Â
All new construction and substantial improvements of any commercial,
industrial or other non-residential structures, including manufactured
homes, shall have the lowest floor, including basement, elevated above
the highest adjacent grade at least at least one (1) foot above the
depth number specified in feet on the community's FIRM [at least
two (2) feet plus feet/foot of freeboard if no depth number is specified]
or together with attendant utilities and sanitary facilities be completely
floodproofed to that so that 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.
c.Â
Adequate drainage paths shall be required around structures
on slopes in order to guide floodwaters around and away from proposed
structures.
A.Â
Located within areas of special flood hazard established in Article II, Section 415.040, 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:
1.Â
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.
2.Â
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.
a.Â
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.
3.Â
If Article IV, Section 415.190(A)(2), is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Article IV.
4.Â
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 IV, Section 415.150(B).
A.Â
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.Â
Be on the site for fewer than one hundred eighty (180) consecutive
days;
2.Â
Be fully licensed and ready for highway use (Note: 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.);
or
3.Â
Meet the permitting, elevating and the anchoring requirements
for manufactured homes of this Chapter.