In all areas of special flood hazards, the following standards are required:
B.
Construction materials and methods.
C.
Utilities.
(1)
All new and replacement water supply systems shall be
designed to minimize or eliminate infiltration of floodwaters into the system;
(2)
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; and
(3)
On-site waste disposal systems shall be located to avoid
impairment to them or contamination from them during flooding.
(4)
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)
All subdivision proposals shall be consistent with the
need to minimize flood damage;
(2)
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)
All subdivision proposals shall have adequate drainage
provided to reduce exposure to flood damage; and
(4)
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. For all new construction and substantial
improvements having 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 must meet
or exceed the following minimum criteria: 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. The bottom of all openings
shall be no higher than one foot above grade. 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 hazards where base flood elevation data have been provided as set forth in § 121-7, Basis for establishing areas of special flood hazard, or in § 121-16B, Use of other base flood data, the following standards are required:
A.
Residential construction.
(1)
New construction and substantial improvement of any residential
structure shall have the lowest floor, including basement, elevated to or
above base flood elevation;
(2)
Require within any AO Zone on the municipality's FIRM
that all new construction and substantial improvement of any residential structure
shall have the lowest floor, including basement, elevated above the highest
adjacent grade at least as high as the depth number specified in feet (at
least two feet if no depth number is specified); and, require adequate drainage
paths around structures on slopes to guide floodwaters around and away from
proposed structures.
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 require within any AO Zone on the municipality's
FIRM that all new construction and substantial improvement of any commercial,
industrial or other nonresidential structure shall either have the lowest
floor, including basement, elevated above the highest adjacent grade at least
as high as the depth number specified in feet (at least two feet if no depth
number is specified); and require adequate drainage paths around structures
on slopes to guide floodwaters around and away from proposed structures; or,
together with the attendant utilities and sanitary facilities, shall:
(1)
Be floodproofed so that below the base flood level the
structure is watertight with walls substantially impermeable to the passage
of water;
(2)
Have structural components capable of resisting hydrostatic
and hydrodynamic loads and effects of buoyancy; and
(3)
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. Such certifications shall be provided to the official as set forth in § 121-16C(2).
Located within areas of special flood hazard established in § 121-7 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 apply:
A.
Encroachments are prohibited, including fill, new construction,
substantial improvements, and other development, unless a technical evaluation
demonstrates that encroachments shall not result in any increase in flood
levels during the occurrence of base flood discharge.
C.
In all areas of special flood hazard in which base flood
elevation data has been provided and no floodway has been designated, the
cumulative effect of any proposed development, when combined with all other
existing and anticipated development, shall not increase the water surface
elevation of the base flood more than 0.2 foot at any point.
