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 movement 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.
(1) All new construction and substantial improvements shall be constructed
with materials and utility equipment resistant to flood damage.
(2) All new construction and substantial improvements shall be constructed
using methods and practices that minimize flood damage.
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;
(3) On-site waste disposal systems shall be located to avoid impairment
to them or contamination from them during flooding; and
(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. 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 covering 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 §
270-7, Basis for establishing areas of special flood hazard, or in §
270-14B, 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
(3) Require
adequate drainage paths around structures on slopes to guide floodwaters
around and away from proposed structures.
B. Nonresidential construction. In an area of special flood hazard,
all new construction and substantial improvement of any commercial,
industrial or other nonresidential structure shall have the lowest
floor, including basement together with the attendant utilities and
sanitary facilities, either:
(1) Elevation.
(a) Elevated to the level of the base flood elevation; and
(b) Within any AO zone on the municipality's DFIRM that all new
construction and substantial improvement of any commercial, industrial
or other nonresidential 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;
or
(2) Floodproofing.
(a) Be floodproofed so that below the base flood level the structure
is watertight with walls substantially impermeable to the passage
of water;
(b)
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 certification shall be provided to the official as set forth in §
270-14C(2)(b).
C. Manufactured homes.
(1) Manufactured homes shall be anchored in accordance with §
270-16A(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.