[Adopted 8-19-2019 by Ord. No. 19-18]
The Legislature of the State of New Jersey has, in N.J.S.A.
40:48-1 et seq., delegated the responsibility to local governmental
units to adopt regulations designed to promote the public health,
safety, and general welfare of its citizenry. Therefore, the Mayor
and Borough Council of the Borough of Tenafly do ordain as follows.
It is the purpose of this chapter to promote the public health,
safety and general welfare and to minimize public and private losses
due to flood conditions in specific areas by provisions designed:
a. To protect human life and health.
b. To minimize expenditure of public money for costly flood-control
projects.
c. To minimize the need for rescue and relief efforts associated with
flooding and generally undertaken at the expense of the general public.
d. To minimize prolonged business interruptions.
e. To minimize damage to public facilities and utilities, such as water
and gas mains, electric, telephone and sewer lines, streets and bridges,
located in areas of special flood hazard.
f. To help maintain a stable tax base by providing for the sound use
and development of areas of special flood hazard so as to minimize
future flood blight areas.
g. To ensure that potential buyers are notified that property is in
an area of special flood hazard.
h. To ensure that those who occupy the areas of special flood hazard
assume responsibility for their actions.
In order to accomplish its purposes, this chapter includes methods
and provisions for:
a. Restricting or prohibiting uses which are dangerous to health, safety
and property due to water or erosion hazards, or which result in damaging
increases in erosion or in flood heights or velocities;
b. Requiring that uses vulnerable to floods, including facilities which
serve such uses, be protected against flood damage at the time of
initial construction;
c. Controlling the alteration of natural floodplains, stream channels,
and natural protective barriers, which help accommodate or channel
floodwaters;
d. Controlling filling, grading, dredging, and other development which
may increase flood damage; and
e. Preventing or regulating the construction of flood barriers, which
will unnaturally divert floodwaters or which may increase flood hazards
in other areas.
[Adopted 8-19-2019 by Ord. No. 19-18]
Unless specifically defined below, words or phrases used in
this chapter shall be interpreted so as to give them the meanings
they have in common usage and to give this chapter its most reasonable
application. As used in this chapter, the following terms shall have
the meanings indicated:
AH ZONE
Areas subject to inundation by 1% annual chance shallow flooding
(usually areas of ponding) where average depths are between one and
three feet. Base flood elevations (BFEs) derived from detailed hydraulic
analyses are shown in this zone.
AO ZONE
Areas subject to inundation by 1% annual chance shallow flooding
(usually sheet flow on sloping terrain) where average depths are between
one and three feet.
APPEAL
A request for a review of the interpretation of any provision
of this chapter or a request for a variance.
AREA OF SHALLOW FLOODING
A designated AO Zone on the Flood Insurance Rate Map (FIRM).
The base flood depths range from one to three feet; a clearly defined
channel does not exist; the path of flooding is unpredictable and
indeterminate; and velocity flow may be evident.
AREA OF SPECIAL FLOOD HAZARD
The land in the floodplain within the Borough subject to
a 1% or greater chance of flooding in any given year. It is shown
on the FIRM as Zone V, VE, V1-30, A, AO, A1-A30, AE, A99, or AH.
BASE FLOOD
A flood having a 1% chance of being equaled or exceeded in
any given year.
BASE FLOOD ELEVATION (BFE)
The flood elevation shown on a published Flood Insurance
Study (FIS), including the Flood Insurance Rate Map (FIRM). For Zones
AE, AH, AO, and A1-30, the elevation represents the water surface
elevation resulting from a flood that has a 1% or greater chance of
being equaled or exceeded in any given year. For Zones VE and V1-30,
the elevation represents the stillwater elevation (SWEL) plus wave
effect (BFE = SWEL + wave effect) resulting from a flood that has
a 1% or greater chance of being equaled or exceeded in any given year.
BASEMENT
Any area of the building having its floor subgrade (below
ground level) on all sides.
BEST AVAILABLE FLOOD HAZARD DATA
The most-recent available flood risk guidance FEMA has provided.
The best available flood hazard data may be depicted on, but not limited
to, advisory flood hazard area maps, work maps or preliminary FIS
and FIRM.
BEST AVAILABLE FLOOD HAZARD DATA ELEVATION
The most-recent available flood elevation FEMA has provided.
The best available flood hazard data elevation may be depicted on
an advisory flood hazard area map, work map or preliminary FIS and
FIRM.
BREAKAWAY WALL
A wall that is not part of the structural support of the
building and is intended, through its design and construction, to
collapse under specific lateral loading forces without causing damage
to the elevated portion of the building or supporting foundation systems.
COASTAL A ZONE
The portion of the special flood hazard area (SFHA) starting
from a Velocity (V) Zone and extending up to the landward limit of
the moderate wave action delineation. Where no V Zone is mapped, the
Coastal A Zone is the portion between the open coast and the landward
limit of the moderate wave action delineation. Coastal A Zones may
be subject to wave effects, velocity flows, erosion, scour, or a combination
of these forces. Construction and development in Coastal A Zones is
to be regulated the same as V Zones/coastal high-hazard areas.
COASTAL HIGH-HAZARD AREA
An area of special flood hazard extending from offshore to
the inland limit of a primary frontal dune along an open coast and
any other area subject to high-velocity wave action from storms or
seismic sources.
DEVELOPMENT
Any man-made change to improved or unimproved real estate,
including, but not limited to, buildings or other structures, mining,
dredging, filling, grading, paving, excavation or drilling operations,
or storage of equipment or materials, located within the area of special
flood hazard.
ELEVATED BUILDING
a.
A nonbasement building:
1.
Built, in the case of a building in an area of special flood
hazard, to have the top of the elevated floor or, in the case of a
building in a coastal high-hazard area or Coastal A Zone, to have
the bottom of the lowest horizontal structural member of the elevated
floor elevated above the base flood elevation plus freeboard by means
of piling, columns (posts and piers), or shear walls parallel to the
flow of the water; and
2.
Adequately anchored so as not to impair the structural integrity
of the building during a flood of up to the magnitude of the base
flood.
b.
In an area of special flood hazard, "elevated building" also
includes a building elevated by the means of fill or solid foundation
perimeter walls with openings sufficient to facilitate the unimpeded
movement of floodwaters.
c.
In areas of coastal high hazard and Coastal A Zones, "elevated
building" also includes a building otherwise meeting the definition
of "elevated building" even though the lower area is enclosed by means
of breakaway walls.
EROSION
The process of gradual wearing away of land masses.
EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including, at a minimum, the installation of utilities,
the construction of streets, and either final site grading or the
pouring of concrete pads) is completed before the effective date of
the floodplain management regulations adopted by a community.
FLOOD INSURANCE RATE MAP or FIRM
The official map on which the Federal Insurance Administration
has delineated both the areas of special flood hazard and the risk
premium zones applicable to the community.
FLOOD INSURANCE STUDY or FIS
The official report in which the Federal Insurance Administration
has provided flood profiles, as well as the Flood Hazard Boundary-Floodway
Map and the water surface elevation of the base flood.
FLOOD or FLOODING
A general and temporary condition of partial or complete
inundation of normally dry land areas from:
a.
The overflow of inland or tidal waters.
b.
The unusual and rapid accumulation or runoff of surface waters
from any source.
FLOODPLAIN MANAGEMENT REGULATIONS
Zoning ordinances, subdivision regulations, building codes,
health regulations, special purpose ordinances (such as a floodplain
ordinance, grading ordinance and erosion control ordinance) and other
applications of police power. The term describes such state or local
regulations, in any combination thereof, which provide standards for
the purpose of flood damage prevention and reduction.
FLOODPROOFING
Any combination of structural and nonstructural additions,
changes, or adjustments to structures which reduce or eliminate flood
damage to real estate or improved real property, water and sanitary
facilities, structures and their contents.
FLOODWAY
The channel of a river or other watercourse and the adjacent
land areas that must be reserved in order to discharge the base flood
without cumulatively increasing the water surface elevation more than
0.2 foot.
FREEBOARD
A factor of safety, usually expressed in feet above a flood
level, for purposes of floodplain management. "Freeboard" tends to
compensate for the many unknown factors that could contribute to flood
heights greater than the height calculated for a selected size flood
and floodway conditions, such as wave action, bridge openings, and
the hydrological effect of urbanization of the watershed.
HIGHEST ADJACENT GRADE
The highest natural elevation of the ground surface, prior
to construction, next to the proposed walls of a structure.
HISTORIC STRUCTURE
Any structure that is:
a.
Listed individually on the National Register of Historic Places
(a listing maintained by the Department of the Interior) or preliminarily
determined by the Secretary of the Interior as meeting the requirements
for individual listing on the National Register;
b.
Certified or preliminarily determined by the Secretary of the
Interior as contributing to the historical significance of a registered
historic district or a district preliminarily determined by the Secretary
to qualify as a registered historic district;
c.
Individually listed on a state inventory of historic places
in states with historic preservation programs which have been approved
by the Secretary of the Interior; or
d.
Individually listed on a local inventory of historic places
in communities with historic preservation programs that have been
certified either:
1.
By an approved state program as determined by the Secretary
of the Interior; or
2.
Directly by the Secretary of the Interior in states without
approved programs.
LIMIT OF MODERATE WAVE ACTION (LiMWA)
The inland limit of the area affected by waves greater than
1.5 feet during the base flood. Base flood conditions between the
V Zone and the LiMWA will be similar to, but less severe than, those
in the V Zone.
LOWEST FLOOR
The lowest floor of the lowest enclosed area (including basement).
An unfinished or flood-resistant enclosure, usable solely for the
parking of vehicles, building access or storage in an area other than
a basement, is not considered a building's lowest floor, provided
that such enclosure is not built so to render the structure in violation
of other applicable nonelevation design requirements of 44 CFR 60.3.
MANUFACTURED HOME
A structure, transportable in one or more sections, which
is built on a permanent chassis and is designed for use with or without
a permanent foundation when attached to the required utilities. The
term "manufactured home" does not include a "recreational vehicle."
NEW CONSTRUCTION
Structures for which the "start of construction" commenced
on or after the effective date of a floodplain regulation adopted
by a community, and includes any subsequent improvements to such structures.
NEW MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including, at a minimum, the installation of utilities,
the construction of streets, and either final site grading or the
pouring of concrete pads) is completed on or after the effective date
of the floodplain management regulations adopted by the municipality.
PRIMARY FRONTAL DUNE
A continuous or nearly continuous mound or ridge of sand
with relatively steep seaward and landward slopes immediately landward
and adjacent to the beach and subject to erosion and overtopping from
high tides and waves from coastal storms. The inland limit of the
primary frontal dune occurs at the point where there is a distinct
change from the relatively steep slope to a relatively mild slope.
RECREATIONAL VEHICLE
A vehicle which is:
a.
Built on a single chassis;
b.
Four hundred square feet or less when measured at the longest
horizontal projections;
c.
Designed to be self-propelled or permanently towable by a light-duty
truck; and
d.
Designed primarily not for use as a permanent dwelling but as
temporary living quarters for recreational, camping, travel, or seasonal
use.
SAND DUNES
Naturally occurring or man-made accumulations of sand in
ridges or mounds landward of the beach.
START OF CONSTRUCTION
[For other than new construction or substantial improvements
under the Coastal Barrier Resources Act (P.L. No. 97-348)], includes
substantial improvements and means the date the building permit was
issued, provided the actual start of construction, repair, reconstruction,
rehabilitation, addition, placement, or other improvement was within
180 days of the permit date. The "actual start" means either the first
placement of permanent construction of a structure on a site, such
as the pouring of a slab or footings, the installation of pilings,
the construction of columns, or any work beyond the stage of excavation,
or the placement of a manufactured home on a foundation. Permanent
construction does not include land preparation, such as clearing,
grading and filling; nor does it include the installation of streets
and/or walkways; nor does it include excavation for basement footings,
piers or foundations or the erection of temporary forms; nor does
it include the installation on the property of accessory buildings,
such as garages or sheds not occupied as dwelling units or not part
of the main structure. For a substantial improvement, the "actual
start of construction" means the first alteration of any wall, ceiling,
floor, or other structural part of a building, whether or not that
alteration affects the external dimensions of the building.
STRUCTURE
A walled and roofed building, a mobile home, or a gas or
liquid storage tank that is principally above ground.
SUBSTANTIAL DAMAGE
Damage of any origin sustained by a structure whereby the
cost of restoring the structure to its before-damaged condition would
equal or exceed 50% of the market value of the structure before the
damage occurred.
SUBSTANTIAL IMPROVEMENT
Any reconstruction, rehabilitation, addition, or other improvement
of a structure, the cost of which equals or exceeds 50% of the market
value of the structure before the "start of construction" of the improvement.
This term includes structures which have incurred "substantial damage,"
regardless of the actual repair work performed. The term does not,
however, include either:
a.
Any project for improvement of a structure to correct existing
violations of state or local health, sanitary or safety code specifications
which have been identified by the local code enforcement officer and
which are the minimum necessary to assure safe living conditions;
or
b.
Any alteration of an "historic structure," provided that the
alteration will not preclude the structure's continued designation
as an "historic structure."
VARIANCE
A grant of relief from the requirements of this chapter which
permits construction in a manner that would otherwise be prohibited
by this chapter.
VIOLATION
The failure of a structure or other development to be fully
compliant with this chapter. A new or substantially improved structure
or other development without the elevation certificate, other certifications,
or other evidence of compliance required in 44 CFR 60.3(b)(5), (c)(4),
(c)(10), (e)(2), (e)(4), or (e)(5) is presumed to be in violation
until such time as that documentation is provided.
[Adopted 8-19-2019 by Ord. No. 19-18]
This chapter shall apply to all areas of special flood hazard
within the jurisdiction of the Borough of Tenafly, Bergen County,
New Jersey.
No structure or land shall hereafter be constructed, relocated
to, extended, converted, or altered without full compliance with the
terms of this chapter and other applicable regulations. Violation
of the provisions of this chapter by failure to comply with any of
its requirements (including violations of conditions and safeguards
established in connection with conditions) shall constitute a misdemeanor.
Any person who violates this chapter or fails to comply with any of
its requirements shall, upon conviction thereof, be fined not more
than $200, imprisoned for not more than 90 days, or both, for each
violation, and in addition shall pay all costs and expenses involved
in the case. Nothing herein contained shall prevent the Borough from
taking such other lawful action as is necessary to prevent or remedy
any violation.
This chapter is not intended to repeal, abrogate, or impair
any existing easements, covenants, or deed restrictions. However,
where this chapter and other ordinance, easement, covenant, or deed
restriction conflict or overlap, whichever imposes the more-stringent
restrictions shall prevail.
In the interpretation and application of this chapter, all provisions
shall be:
a. Considered as minimum requirements.
b. Liberally construed in favor of the Borough Council.
c. Deemed neither to limit nor repeal any other powers granted under
state statutes.
The degree of flood protection required by this chapter is considered
reasonable for regulatory purposes and is based on scientific and
engineering considerations. Larger floods can and will occur on rare
occasions. Flood heights may be increased by man-made or natural causes.
This chapter does not imply that land outside the areas of special
flood hazard or uses permitted within such areas will be free from
flooding or flood damages. This chapter shall not create liability
on the part of the Borough or any officer or employee thereof or the
Federal Insurance Administration for any flood damages that result
from reliance on this chapter or any administrative decision lawfully
made thereunder.
[Adopted 8-19-2019 by Ord. No. 19-18]
A development permit shall be obtained before construction or development begins, including placement of manufactured homes, within any area of special flood hazard established in Subsection
24-3.2. Application for a development permit shall be made on forms furnished by the Planning Board and may include, but not be limited to, plans, in duplicate, drawn to scale, showing the nature, location, dimensions, and elevations of the area in question; existing or proposed structures; fill; storage of materials; drainage facilities; and the location of the foregoing. Specifically, the following information is required:
a. Elevation, in relation to mean sea level, of the lowest floor (including
basement) of all structures;
b. Elevation, in relation to mean sea level, to which any structure
has been floodproofed;
c. Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in Subsection
24-5.2b; and
d. A description of the extent to which any watercourse will be altered
or relocated as a result of proposed development.
The Construction Official/Zoning Official is hereby appointed
to administer and implement this chapter by granting or denying development
permit applications in accordance with its provisions.
Duties of the Construction Official/Zoning Official shall include,
but not be limited to:
a. Permit review:
1. Review all development permits to determine that the permit requirements
of this chapter have been satisfied.
2. Review all development permits to determine that all necessary permits
have been obtained from those federal, state or local governmental
agencies from which prior approval is required.
3. Review all development permits to determine if the proposed development is located within the floodway. If it is located in the floodway, assure that the encroachment provisions of Subsection
24-5.3 are met.
4. Review all development permits in the coastal high-hazard and Coastal
A Zone area to determine if the proposed development alters sand dunes
or other natural coastal protections so as to increase potential flood
damage.
5. Review plans for walls to be used to enclose space below the base
flood level in accordance with Subsection 24-5.4.b4.
b. Use of other base flood data: When base flood elevation and floodway data has not been provided in accordance with Subsection
24-3.2, Basis for Establishing Areas of Special Flood Hazard, the Construction Official/Zoning Official shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer Subsection
24-5.2a, Specific Standards, Residential construction, and Subsection
24-5.2b, Specific Standards, Nonresidential construction.
c. Information to be obtained and maintained:
1. Obtain and record the actual elevation (in relation to mean sea level)
of the lowest floor (including basement) of all new or substantially
improved structures, and whether or not the structure contains a basement.
2. For all new substantially improved floodproofed structures: verify and record the actual elevation (in relation to mean sea level); and maintain the floodproofing certifications required in Subsection
24-4.1c.
3. In coastal high-hazard and Coastal A Zone areas, certification shall be obtained from a registered professional engineer or architect that the provisions of Subsections
24-5.4b1 and
24-5.4b2(a) and
(b) are met.
4. Maintain for public inspection all records pertaining to the provisions
of this chapter.
d. Alteration of watercourses:
1. Notify adjacent communities and the State Department of Environmental
Protection, Bureau of Flood Control, and the Land Use Regulation Program,
prior to any alteration of relocation of a watercourse and submit
evidence of such notification to the Federal Insurance Administration.
2. Require that maintenance is provided within the altered or relocated
portion of the watercourse so that the flood-carrying capacity is
not diminished.
e. Substantial damage review:
1. After an event resulting in building damages, assess the damage to
structures due to flood and nonflood causes.
2. Record and maintain the flood and nonflood damage of substantial
damage structures and provide a letter of substantial damage determination
to the owner and the New Jersey Department of Environmental Protection,
Bureau of Flood Control.
3. Ensure substantial improvements meet the requirements of Subsections
24-5.2a, Specific Standards, Residential construction; 24-5.2b, Specific Standards, Nonresidential construction; and 24-5.2c, Specific Standards, Manufactured homes.
f. Interpretation of FIRM boundaries: make interpretations, where needed, as to the exact location of the boundaries of the areas of special flood hazard (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Subsection
24-4.4.
[Adopted 8-19-2019 by Ord. No. 19-18]
In all areas of special flood hazard, 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:
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 to be placed or substantially improved 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.
4. For all new construction and substantial improvements, the 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 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.
4. Base flood elevation data shall be provided for subdivision proposals
and other proposed new development which 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 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 hazard where base flood elevation data have been provided as set forth in Subsection
24-3.2, Basis for Establishing Areas of Special Flood Hazard, or in Subsection
24-4.3b, Use of Other Base Flood Data, the following standards are required:
a. Residential construction.
1. For Coastal A Zone construction, see Subsection 25-5.4, Coastal High-Hazard
Areas and Coastal A Zones.
2. New construction and substantial improvement of any residential structure
located in an A or AE 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: base flood elevation (published FIS/FIRM) plus one foot, the best
available flood hazard data elevation plus one foot, or as required
by ASCE/SEI 24-14, Table 2-1.
3. 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, together with the
attendant utilities and sanitary facilities, elevated 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), or at
or above the best available flood hazard data elevation plus one foot,
whichever is more restrictive; and 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 located in an A or AE Zone (for Coastal A Zone construction see Subsection
24-5.4, Coastal High-Hazard Areas and Coastal A Zones) 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:
1. Either:
(a)
Elevated at or above the more restrictive of: base flood elevation
(published FIS/FIRM) plus one foot, the best available flood hazard
data elevation plus one foot, or as required by ASCE/SEI 24-14, Table
2-1;
(b)
Require within any AO or AH Zone 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), or at or above the best available flood
hazard data elevation plus one foot, whichever is more restrictive;
and require adequate drainage paths around structures on slopes to
guide floodwaters around and away from proposed structures.
2. Or:
(a)
Be floodproofed so that below the more restrictive of: base
flood elevation (published FIS/FIRM) plus one foot, the best available
flood hazard data elevation plus one foot, or as required by ASCE/SEI
24-14, Table 6-1, 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
(c)
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 Subsection
24-4.2.
c. Manufactured homes.
1. Manufactured homes shall be anchored in accordance with Subsection
24-5.1a2.
2. All manufactured homes to be placed or substantially improved within
an area of special flood hazard shall:
(a)
Be consistent with the need to minimize flood damage;
(b)
Be constructed to minimize flood damage;
(c)
Have adequate drainage provided to reduce exposure to flood
damage;
(d)
Be elevated on a permanent foundation such that the top of the
lowest floor is at or above the more restrictive of: base flood elevation
(published FIS/FIRM) plus one foot, the best available flood hazard
data elevation plus one foot, or as required by ASCE/SEI 24-14, Table
2-1; and
(e)
The manufactured home chassis is supported by reinforced piers
or other foundation elements of at least equivalent strength that
are no less than 36 inches in height above grade and be securely anchored
to an adequately anchored foundation system to resist flotation, collapse,
and lateral movement.
Coastal high-hazard areas (V or VE Zones) and Coastal A Zones are located within the areas of special flood hazard established in Subsection
24-3.2. 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 buildings or structures shall be located landward of the reach
of the mean high tide.
2. The placement of manufactured homes shall be prohibited, except in
an existing manufactured home park or subdivision.
b. Construction methods.
1. Elevation. All new construction and substantial improvements shall
be elevated on piling or columns so that:
(a)
The bottom of the lowest horizontal structural member of the
lowest floor (excluding the piling or columns) is elevated at or above
the more restrictive of: base flood elevation (published FIS/FIRM)
plus one foot, the best available flood hazard data elevation plus
one foot, or as required by ASCE/SEI 24-14, Table 4-1;
(b)
All electrical, heating, ventilating, air-conditioning, and
mechanical equipment and other equipment servicing the building is
elevated at or above the more restrictive of: base flood elevation
(published FIS/FIRM) plus one foot, the best available flood hazard
data elevation plus one foot, or as required by ASCE/SEI 24-14, Table
4-1; and
(c)
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 or in Subsection
24-5.4b4.
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 1% chance of being equaled or exceeded in any given year
(100-year mean recurrence interval).
(c)
Prohibit the use of fill for structural support of buildings
within Zones V1-30, VE, V, and Coastal A on the community's FIRM.
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 Subsections
24-5.4b1 and
24-5.4b2(a) and
(b).
4. Space below the lowest floor.
(a)
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 lattice-work
or insect screening are used as provided for in this section.
(b)
Breakaway walls, open wood lattice-work 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 designs proposed meet the following conditions.
(1)
Breakaway wall collapse shall result from a water load less
than that which would occur during the base flood; and
(2)
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 used shall be those associated with the base flood. Wind loading
values used shall be those required by applicable state or local building
standards.
(c)
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.
(d)
Prior to construction, plans for any breakaway wall must be
submitted to the Construction Code Official or Building Subcode Official
for approval.
c. Sand dunes. Prohibit man-made alteration of sand dunes within Coastal
A Zones, VE and V Zones on the community's FIRM which would increase
potential flood damage.