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 that contains 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 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.
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:
(1) 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;
(2) The bottom of all openings shall be no higher than one foot above
grade; and
(3) 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 §
219-7, Basis for establishing areas of special flood hazard, or in §
219-14B, 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 a basement, together with the
attendant utilities and sanitary facilities, elevated to at least
one foot above the base flood elevation;
(2) Within any AO Zone on the municipality's DFIRM, all new construction
and substantial improvement of any residential structure shall have
the lowest floor, including a basement, elevated above the highest
adjacent grade, at least as high as the depth number specified in
feet, or at least two feet if no depth number is specified; and
(3) Adequate drainage paths are required 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:
(1) Have the lowest floor, including a basement, elevated to the level
of the base flood elevation; and
(2) Within any AO Zone on the municipality's DFIRM, all new construction
and substantial improvement of any commercial, industrial, or other
nonresidential structure shall have:
(a)
The lowest floor, including a basement, elevated above the highest
adjacent grade at least as high as the depth number specified in feet,
or at least two feet if no depth number is specified, with required
adequate drainage paths around structures on slopes to guide floodwaters
around and away from proposed structures; or
[1]
Be floodproofed so that below the base flood level, the structure
is watertight with walls substantially impermeable to the passage
of water; and
[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 section. Such certification shall be provided to the official as set forth in §
219-14C(2)(b).
C. Manufactured homes.
(1) Manufactured homes shall be anchored in accordance with §
219-16A(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 least one foot above the
base flood elevation.
Located within areas of special flood hazard established in §
219-7 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris, potential projectiles, and erosion potential, the following provisions apply:
A. Prohibit encroachments, including fill, new construction, substantial
improvements, and other development, unless a technical evaluation
demonstrates that encroachment 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 must comply with Article
V, Flood Hazard Reduction.
C. In all areas of special flood hazard that 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.