In all areas of special flood hazards, the following
standards 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 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.
[Amended 3-5-1987 by Ord. No. 87-11]
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 designed 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.
[Added 3-5-1987 by Ord. No. 87-11]
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. 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. Designs for meeting this requirement must either be
certified by a registered professional engineer or architect or 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.
[Added 3-5-1987 by Ord. No. 87-11]
[Amended 3-5-1987 by Ord. No. 87-11; 6-11-2009 by Ord. No.
2009-06; 9-24-2009 by Ord. No. 2009-06A]
In all areas of special flood hazards where base flood elevation data has been provided as set forth in §Â
199-8 or
199-15B, the following standards are required:
A. Residential construction.
(1)Â New construction and substantial improvement of any residential structure
shall have the lowest floor, including basement, together with the
attendant utilities and sanitary facilities, elevated to or above
base flood elevation.
(2)Â 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 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:
(1)Â Either:
(a)Â
Have the lowest floor, including basement, together with the
attendant utilities and sanitary facilities, elevated to the level
of the base flood elevation; and
(b)Â
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 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.
(2) Or, together with the attendant utilities and sanitary facilities, 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 effect of buoyancy; c) be certified by a registered professional engineer or architect as meets the accepted design and methods of construction standards of the applicable provisions of this subsection. Such certification shall be provided to the official as set forth in §Â
199-15C(2)(b).
C. Manufactured homes.
(1)Â Manufactured homes, if permitted in Chapter
220, Land Use, shall be anchored in accordance with §Â
199-17A(2).
(2)Â 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
199-8 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, including fill, new construction, substantial
improvements and other development, are 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. 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 pilings or columns) is elevated to or above the base flood level, with all space below the lowest floor's supporting member open so as not to impede the flow of water, except for breakaway walls as provided for in Subsection
E.
C. Structural support.
(1)Â All new construction and substantial improvements
shall be securely anchored on pilings or columns.
(2)Â 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 one-percent chance of being equaled or exceeded
in any given year (one-hundred-year mean recurrence interval).
(3)Â There shall be no fill used for structural support.
D. 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 Subsections
B and
C(1) and
(2).
E. Space below the lowest floor.
(1)Â Any alteration, repair, reconstruction or improvement
to a structure started after the enactment of this chapter shall not
enclose the space below the lowest floor unless breakaway walls, open
wood latticework or insect screening are used as provided for in this
subsection.
(2)Â Breakaway walls, open wood latticework 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 design proposed meets the following conditions:
(a)Â
Breakaway wall collapse shall result from a
water load less than that which would occur during the base flood.
(b)Â
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).
(3)Â 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.
(4)Â Prior to construction, plans for any breakaway wall
must be submitted to the Township Engineer for approval.