In all areas of special flood hazards, compliance with the applicable
requirements of the Uniform Construction Code (N.J.A.C. 5:23) and
the following standards, whichever is more restrictive, is required.
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 in at least two exterior walls of each enclosed
area, 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 §
270-12, Basis for establishing areas of special flood hazard, or in § 270-25, Use of other base flood data, the following standards are required.
New construction and substantial improvement of any residential
structure located in an A, AE, AO or AH zone shall have the lowest
floor, including basement, together with the attendant utilities (including
all electrical, heating, ventilating, air-conditioning and other service
equipment) and sanitary facilities, elevated at or above the more
restrictive of the following:
A. For A or AE zones:
(1) Base flood elevation (published FIS/FIRM) plus one foot;
(2) The best available flood hazard data elevation plus one foot;
(3) As required by ASCE/SEI 24-14, Table 2-1; or
(4) As required by N.J.A.C. 7:13-3.
B. For AO or AH zones on the municipality's FIRM to elevate above the
depth number specified in feet plus one foot, above the highest adjacent
grade (at least three 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.
C. Record the method and elevation used above and the best available
flood hazard design data elevation, date, and revision in the local
development permit.
In an area of special flood hazard, all new construction and
substantial improvement of any commercial, industrial or other nonresidential
structure located in an A, AE, AO or AH zone shall have the lowest
floor, including basement together with the attendant utilities and
sanitary facilities, as well as all electrical, heating, ventilating,
air-conditioning and other service equipment shall either:
A. Be elevated at or above the more restrictive of the following:
(1) For A or AE zones:
(a)
Base flood elevation (published FIS/FIRM) plus one foot;
(b)
The best available flood hazard data elevation plus one foot;
(c)
As required by ASCE/SEI 24-14, Table 2-1; or
(d)
As required by N.J.A.C 7:13-3.
(2) For AO or AH zones on the municipality's FIRM to elevate above the
depth number specified in feet plus one foot, above the highest adjacent
grade (at least three 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;
(3) Record the method and elevation used above and, the best available
flood hazard design data elevation, date and revision in the local
development permit.
B. Or, be floodproofed so that below the more restrictive of the following:
(1) For A or AE Zones:
(a)
Base flood elevation (published FIS/FIRM) plus one foot;
(b)
The best available flood hazard data elevation plus one foot;
(c)
As required by ASCE/SEI 24-14, Table 6-1;
(d)
As required by N.J.A.C 7:13-3; or
(e)
AO or AH zone elevation based upon the highest adjacent grade,
plus the depth number specified in feet, plus one foot (at least three
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) The structure is watertight with walls substantially impermeable
to the passage of water;
(3) Have structural components capable of resisting hydrostatic and hydrodynamic
loads and effects of buoyancy;
(4) 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 §
270-23C(2)(b); and
(5) Record the method and elevation used above and, the best available
flood hazard design data elevation, date and revision in the local
development permit.
Located within areas of special flood hazard established in §
270-12 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. 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 §
270-51A is satisfied, all new construction and substantial improvements must comply with Article
V of this chapter.
C. In all areas of special flood hazard in which base flood elevation
data has been provided and no floodway has been designated, no new
construction, substantial improvements, fill, or other development
shall be permitted, unless it is demonstrated that the accumulative
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 2/10 foot at any point.