In all areas of special flood hazard, including X Zones, 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, temporary and accessory structures, decks
and patios 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 floodwaters into the system;
(2)
New and replacement sanitary sewage systems and waste lines shall
be designed to minimize or eliminate infiltration of floodwaters into
the systems and discharge from the systems into floodwaters, either
or by elevation or by installation of check valves and backflow preventers;
(3)
On-site waste disposal systems shall be located to avoid impairment
to them or contamination from them during flooding; and
(4)
For all new construction and substantial improvements, 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 and new development proposals.
(1)
All subdivision proposals and other proposed new development shall
be consistent with the need to minimize flood damage;
(2)
All subdivision proposals and other proposed new development 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 and other proposed new development shall
have adequate drainage provided to reduce exposure to flood damage;
and
(4)
Base flood elevation data shall be provided for subdivision proposals
and any other proposed new development.
E.
Freeboard. All new construction and substantially improved residential and nonresidential structures located in an area of special flood hazard shall have the lowest floor elevated to the base flood elevation or advisory base flood elevation, whichever is applicable, plus freeboard as specified in Table I below. Enclosed areas that are used solely for parking, building access, or storage are not the lowest floor and shall be allowed below the BFE/ABFE, provided the enclosed areas meet the requirement set forth in § 104-16E above. For all zones within the City of Hoboken, freeboard shall be measured from the bottom of the lowest horizontal structural member.
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Table I
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Freeboard Requirements for Areas of Special Flood Hazard
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Building Type
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Zones
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X
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A
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Coastal A
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V
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Residential structures
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+1 foot
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+1 foot
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+1 foot
|
+2 feet
| |
|
Building and other structures with school or day-care facilities;
and other nonresidential structures not itemized below
|
+1 foot
|
+1 foot
|
+2 feet
|
+2 feet
| |
|
Essential facilities, including, but not limited to; fire, rescue,
ambulance, and police stations and emergency vehicle garages; buildings
designated as emergency shelters; other facilities required for emergency
response; hospitals and other health care facilities having surgery
or emergency treatment facilities; power-generating stations and other
public utility facilities
|
+1 foot
|
+2 feet
|
+2 feet
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+3 feet
| |
|
Buildings and other facilities that manufacture, process, handle,
store, use, or dispose of hazardous materials
|
+1 foot
|
+2 feet
|
+2 feet
|
+3 feet
| |
|
Temporary structures
|
N/A
|
+1 foot
|
+2 feet
|
N/A
| |
F.
Fill. Fill shall not be used to elevate structures or for structural
support.
In all areas of special flood hazard including all A Zones and areas subject to moderate wave action, where base flood elevation data have been provided as set forth in § 104-7, Basis for establishing the areas of special flood hazard, or in § 104-14B, Use of other base flood and floodway 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, together with the
attendant utilities and sanitary facilities, elevated to or above
the base flood elevation or advisory base flood elevation, whichever
is more restrictive, plus freeboard; or
(2)
Require within any A 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) or at
or above the advisory base flood elevation, whichever is more restrictive,
plus freeboard; and require adequate drainage paths around structures
on slopes to guide floodwaters around and away from proposed structures.
(3)
Fully enclosed areas above grade but below the lowest floor are usable
only for parking of vehicles (where permitted), building access and/or
storage and not for human habitation. Fully enclosed areas subject
to flooding shall be designed to automatically equalize hydrostafic
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 and must
meet or exceed the following minimum criteria:
(a)
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;
(b)
The bottom of all openings shall be no higher than one foot
above grade; and
(c)
Openings may be equipped with screens, louvers, or other coverings
or devices, provided that they permit the automatic entry and exit
of floodwaters.
B.
Nonresidential and mixed-use construction. In an area of special
flood hazard, all new construction and substantial improvement of
any commercial, industrial or other nonresidential structure, or any
mixed-use structure where residential uses exist above commercial
uses on lower floors, shall have the lowest floor, including basement,
together with the attendant utilities and sanitary facilities, either:
(1)
Elevated to or above the level of the base flood elevation or advisory
base flood elevation, whichever is more restrictive, plus freeboard;
(2)
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) or at or above the advisory base flood elevation, whichever
is more restrictive, plus freeboard; and require adequate drainage
paths around structures on slopes to guide floodwaters around and
away from proposed structures; or
(3)
Be floodproofed so that below the base flood elevation or advisory
base flood elevation (whichever is more restrictive), plus freeboard,
the structure is watertight with walls substantially impermeable to
the passage of water;
(4)
Have structural components capable of resisting hydrostatic and hydrodynamic
loads and effects of buoyancy; and
(5)
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 Administrator as set forth in § 104-14C(2).
(6)
In areas of moderate wave action where floodproofing is not feasible
or desirable, fully enclosed areas below the lowest floor used for
nonresidential uses, parking, building access or storage 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 and must meet or exceed the following
minimum criteria:
(a)
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.
(b)
The bottom of all openings shall be no higher than one foot
above grade.
(c)
Openings may be equipped with screens, louvers, or other coverings
or devices, provided that they permit the automatic entry and exit
of floodwaters; and
(7)
Only flood-damage-resistant materials, so classified by the National
Flood Insurance Program (NFIP), shall be used. Areas shall be constructed
to withstand direct and prolonged contact with floodwaters without
sustaining significant damage.
Located within areas of special flood hazard established in § 104-7 may be 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 encroachment shall not result in any increase in
flood levels during the occurrence of the base flood discharge.
C.
In all areas of special flood hazard in which base flood elevation
data have 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 two-tenths of a foot at any
point.
Costal high-hazard areas (V Zones) are located within the areas of special flood hazard established in § 104-7. These areas have special flood hazards associated with high-velocity waters from tidal surges and hurricane wave wash; therefore, the following provisions shall apply:
A.
Location of structures.
(1)
All construction shall be landward of the mean high tide established
and updated from time to time by the appropriate governmental agency
with jurisdiction over same. Functionally dependent uses, open space
and outdoor passive and active recreational uses may be permitted
seaward of the mean high tide, provided that such use creates no additional
threat to public safety and complies with the applicable requirement
of this chapter.
B.
Construction methods.
(1)
Elevation. All new construction and substantial improvements shall
be elevated on piling 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 elevation or advisory
base flood elevation, whichever is more restrictive, plus freeboard.
(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 one-percent chance of being equaled or exceeded in any
given year (one-hundred-year mean recurrence interval).
(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 § 104-19B(1) and (2)(a) and (b).
C.
Space below the lowest floor.
(1)
Floodproofing methods shall not be used in the V Zone for space below
the lowest floor.
(2)
Only flood-damage-resistant materials, so classified by the National
Flood Insurance Program (NFIP), shall be used in construction of areas
below the lowest floor. Areas shall be constructed to withstand direct
and prolonged contact with floodwaters without sustaining significant
damage.
(3)
Any alteration, repair, reconstruction or improvement to a structure
started after the enactment of this amendment shall not enclose the
space below the lowest floor unless with breakaway walls, or other
screening 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:
(a)
Breakaway wall collapse shall result from a water load less
than that which would occur during the base flood; and
(b)
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 shall be those associated with the base flood. Wind loading
values shall be those required by applicable state and local building
standards.
(c)
Where 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 Floodplain Administrator for approval.
