In all areas of special flood hazards, the following provisions
are required for all new construction and substantial improvements:
A.
All new construction or 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 or substantial improvements shall be constructed
by methods and practices that minimize flood damage;
C.
All new construction or substantial improvements shall be constructed
with materials resistant to flood damage;
D.
All new construction or substantial improvements shall be constructed
with electrical, heating, ventilation, 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 shall 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 floodwaters into the system
and discharge from the systems into floodwaters; and
G.
On-site waste disposal systems shall be located to avoid impairment
to them or contamination from them during flooding.
In all areas of special flood hazards where base flood elevation data has been provided as set forth in Article III, § 151-7, Article IV, § 151-14H, or Article V, § 151-19C, the following provisions are required:
A.
Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement), elevated to or above the base flood elevation. A registered professional engineer, architect, or land surveyor shall submit a certification to the Floodplain Administrator that the standard of this subsection as proposed in Article IV, § 151-15A(1), is satisfied.
B.
Nonresidential construction. New construction and substantial improvements
of any commercial, industrial or other nonresidential structure shall
either have the lowest floor (including basement) elevated to or above
the base flood level or together with attendant utility and sanitary
facilities, be designed so that below the base flood level 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 registered
professional engineer or architect shall develop and/or review structural
design, specifications, and plans for the construction, and shall
certify that the design and methods of construction are in accordance
with accepted standards of practice as outlined in this subsection.
A record of such certification which includes the specific elevation
(in relation to mean sea level) to which such structures are floodproofed
shall be maintained by the Floodplain Administrator.
C.
Enclosures. New construction and substantial improvements, with 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
the entry and exit of floodwaters. Designs for meeting this requirement
must either be certified by a registered professional engineer or
architect or meet or exceed the following minimum criteria:
(1)
A minimum of two openings on separate walls having a total net area
of not less than one square inch for every square foot of enclosed
area subject to flooding shall be provided.
(2)
The bottom of all openings shall be no higher than one foot above
grade.
(3)
Openings may be equipped with screens, louvers, valves, or other
coverings or devices, provided that they permit the automatic entry
and exit of floodwaters.
D.
Manufactured homes.
(1)
Require that all manufactured homes to be placed within Zone A on
a community's FHBM or FIRM shall be installed using methods and
practices which 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.
This requirement is in addition to applicable state and local anchoring
requirements for resisting wind forces.
(2)
Require that manufactured homes that are placed or substantially
improved within Zones A1-30, AH, and AE on the community's FIRM
on sites outside of a 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 a result of a flood, be elevated on a permanent
foundation such that the lowest floor of the manufactured home is
elevated to or above the base flood elevation and be securely anchored
to an adequately anchored foundation system to resist flotation, collapse,
and lateral movement.
(3)
Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision with Zones A1-30, AH and AE on the community's FIRM that are not subject to the provisions of Subsection D of this section be elevated so that either:
(a)
The lowest floor of the manufactured home is at or above the
base flood elevation; or
(b)
The manufactured home chassis is supported by reinforced piers
or other foundation elements of at least equivalent strength that
are no less than 36 inches in height above grade and be securely anchored
to an adequately anchored foundation system to resist flotation, collapse,
and lateral movement.
E.
Recreational vehicles. Require that recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community's FIRM either be on the site for fewer than 180 consecutive days, or be fully licensed and ready for highway use, or meet the permit requirements of Article IV, § 151-15A, and the elevation and anchoring requirements for manufactured homes in Subsection D of this section. 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.
C.
Base flood elevation data shall be generated for subdivision proposals and other proposed development including the placement of manufactured home parks and subdivisions which is greater than 50 lots or five acres, whichever is lesser, if not otherwise provided pursuant to Article III, § 151-7 or Article IV, § 151-14H, of this chapter.
D.
All subdivision proposals including the placement of manufactured
home parks and subdivisions shall have adequate drainage provided
to reduce exposure to flood hazards.
E.
All subdivision proposals including the placement of manufactured
home parks and subdivisions shall have public utilities and facilities
such as sewer, gas, electrical and water systems located and constructed
to minimize or eliminate flood damage.
Located within the areas of special flood hazard established in Article III, § 151-7, Section B, are areas designated as shallow flooding. These areas have special flood hazards associated with flood depths of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:
A.
All new construction and substantial improvements of residential
structures have the lowest floor (including basement) elevated to
or above the base flood elevation or the highest adjacent grade at
least as high as the depth number specified in feet on the community's
FIRM (at least two feet if no depth number is specified); or
B.
All new construction and substantial improvements of nonresidential
structures:
(1)
Have the lowest floor (including basement) elevated to or above the
base flood elevation or the highest adjacent grade at least as high
as the depth number specified in feet on the community's FIRM
(at least two feet if no depth number is specified); or
(2)
Together with attendant utility and sanitary facilities be designed
so that below the base specified flood depth in an AO Zone, or below
the base flood elevation in an AH Zone, 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 of effects of buoyancy.
D.
Require within Zones AH or AO adequate drainage paths around structures
on slopes, to guide floodwaters around and away from proposed structures.
