In all areas of special flood hazard, the following
provisions are required:
A. Anchoring.
(1)Â All new construction and substantial improvements
shall be anchored to prevent flotation, collapse or lateral movement
of the structure.
(2)Â All manufactured homes shall be 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.
B. Construction materials and methods.
(1)Â All new construction and substantial improvements
shall be constructed with materials and utility equipment resistant
to flood damage.
(2)Â All new construction and substantial improvements
shall be constructed using methods and practices that minimize flood
damage.
C. Utilities.
(1)Â All new and replacement water supply systems shall
be designated to minimize or eliminate infiltration of floodwaters
into the system.
(2)Â New and replacement sanitary sewage systems shall
be designed to minimize or eliminate infiltration of floodwaters into
the systems and discharge from the systems into floodwaters.
(3)Â On-site waste disposal systems shall be located to
avoid impairment to them or contamination from them during flooding.
(4)Â Electrical, heating, ventilation, plumbing and air-conditioning
equipment and other service facilities shall be designed and/or located
so as to prevent water from entering or accumulating within the components
during conditions of flooding.
D. Subdivision proposals.
(1)Â All subdivision proposals shall be consistent with
the need to minimize flood damage.
(2)Â All subdivision proposals shall have public utilities
and facilities, such as sewer, gas, electrical and water systems,
located and constructed to minimize flood damage.
(3)Â All subdivision proposals shall have adequate drainage
provided to reduce exposure to flood damage.
(4)Â Base flood elevation data shall be provided for subdivision
proposals and other proposed development which contain at least 50
lots or five acres, whichever is less.
E. Enclosure openings.
(1)Â For all new construction and substantial improvements,
fully enclosed areas below the lowest floor 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.
(2)Â Designs for meeting this requirement must either be
certified by a registered professional engineer or architect or must
meet or exceed the following minimum criteria:
(a)Â
A minimum of two openings 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.
(b)Â
The bottom of all openings shall be no higher
than one foot above grade.
(c)Â
Openings may be equipped with screens, louvers
or other coverings or devices, provided that they permit the automatic
entry and exit of floodwaters.
In all areas of special flood hazard where base flood elevation data have been provided as set forth in §Â
102-111, Basis for establishing areas of special flood hazard, or in §Â
102-118B(2), Use of other base flood data, the following standards are required:
A. Residential construction. New construction and substantial
improvement of any residential structure shall have the lowest floor,
including the basement, elevated to or above base flood elevation.
B. Nonresidential construction. New construction and
substantial improvement of any commercial, industrial or other nonresidential
structure shall either have the lowest floor, including basement,
elevated to the level of the base flood elevation or, together with
attendant utility and sanitary facilities, shall:
(1)Â Be floodproofed so that below the base flood level
the structure is watertight with walls substantially impermeable to
the passage of water;
(2)Â Have structural components capable of resisting hydrostatic
and hydrodynamic loads and effects of buoyancy; and
(3)Â Be certified by a registered professional engineer
or architect that the design and methods of construction are in accordance
with accepted standards of practice for meeting the applicable provisions
of this subsection.
C. Manufactured homes. All manufactured homes to be placed
or substantially improved within an area of special flood hazard shall
be elevated on a permanent foundation such that the top of the lowest
floor is at or above the base flood elevation.
Located within areas of special flood hazard established in §Â
102-111 are areas designated as "floodways." Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles and erosion potential, the following provisions shall apply:
A. Encroachments, including fill, new construction, substantial
improvements and other development, shall be prohibited unless a technical
evaluation demonstrates that encroachments shall not result in any
increase in flood levels during the occurrence of the base flood discharge.
B. If Subsection
A is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this article.