[Ord. No. 1099 § 5.1]
In all areas of special flood hazards the following standards
are required:
A.
Anchoring.
(1)
All new construction and substantial improvements shall be anchored
to prevent flotation, collapse, or lateral improvement of the structure.
(2)
All manufactured homes shall be anchored to resist flotation, collapse
or lateral movement. Methods of anchoring may include, but are not
to be 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.
C.
Utilities.
(1)
All new and replacement water supply systems shall be designed to
minimize or eliminate infiltration of flood waters into the system.
(2)
New and replacement sanitary sewage systems shall be designed to
minimize or eliminate infiltration of flood waters into the systems
and discharge from the systems into flood waters.
(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.
(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,
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 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 or 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 covering or devices provided that they
permit the automatic entry and exit of floodwaters.
[Ord. No. 1099 § 5.2]
In all areas of special flood hazards where base flood elevation data have been provided as set forth in Section 195-7, Basis for establishing the areas of special flood hazard or in Section 195-14B, 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
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
(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.
(3)
Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards or practice for meeting the applicable provisions of this subsection. Such certification shall be provided to the official as set forth in Section 195-14C(2).
C.
Manufactured homes.
(1)
Manufactured homes shall be anchored in accordance with Section 195-16A(2).
(2)
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.
[Ord. No. 10-99 § 5.3]
Coastal high hazard areas (V Zones) are located within the areas of special flood hazard established in Section 195-7. These areas have special flood hazards associated with high velocity waters from tidal surges and hurricane wave wash; therefore, the following provisions shall apply:
B.
Construction methods.
(1)
Elevation. All new construction and substantial improvements shall be elevated on pilings or columns so that the bottom of the lowest horizontal structural member of the lowest floor (excluding the piling or columns) is elevated to or above the base flood level, as not to impede the flow of water, except for breakaway walls as provided for in Subsection B(4) below.
(2)
Structural support.
(a)
All new construction and substantial improvements shall be securely
anchored on piling or columns.
(b)
The pile or column foundation and structure attached thereto
shall be anchored to resist flotation, collapse or lateral movement
due to the effects of wind and water loading values each of which
shall have a 1% chance of being equaled or exceeded in any given year
(one-hundred-year mean recurrence interval).
(c)
There shall be no fill used for structural support.
(3)
Certification. A registered professional engineer or architect shall
develop or review the structural design specifications and plans for
the construction and shall certify that the design and methods of
construction to be used are in accordance with accepted standards
of practice for compliance with the provisions of paragraphs B(1)
and B(2)(a) and (b) above.
(4)
Space below the lowest floor.
(a)
Any alteration, repair, reconstruction or improvement to a structure
started after the enactment of the ordinance codified in this chapter
shall not enclose the space below the lowest floor unless breakaway
walls, open wood lattice-work or insect screening are used as provided
for in this section.
(b)
Breakaway walls, open wood lattice-work or insect screening
shall be allowed below the base flood elevation provided that they
are intended to collapse under wind and water loads without causing
collapse, displacement or other structural damage to the elevated
portion of the building or supporting foundation system. Breakaway
walls shall be designed for a safe loading resistance of not less
than 10 and no more than 20 pounds per square foot. Use of breakaway
walls which exceed a design safe loading of 20 pounds per square foot
(either by design or when so required by local or State codes) may
be permitted only if a registered professional engineer or architect
certifies that the designs proposed meet the following conditions:
[1]
Breakaway wall collapse shall result from a water load less
than that which would occur during the base flood.
[2]
The elevated portion of the building and supporting foundation
system shall not be subject to collapse, displacement or other structural
damage due to the effects of wind and water load acting simultaneously
on all building components (structural and nonstructural). Water loading
values used shall be those associated with the base flood. Wind loading
values used shall be those required by applicable State or local building
standards.
(c)
If breakaway walls are utilized, such enclosed space shall be
used solely for parking of vehicles, building access, or storage and
not for human habitation.
(d)
Prior to construction, plans for any breakaway wall must be
submitted to the local administrator for approval.
C.
Sand dunes. There shall be no alteration of sand dunes which would
increase potential flood damage.
