The following standards apply to new development, including new and substantially improved structures, in the areas of special flood hazard zone shown on the Flood Insurance Rate Map designated in §
169-6:
A. Coastal high-hazard areas and Coastal A Zones. The following requirements
apply within VE and Coastal A Zones:
[Amended 11-14-2023 by L.L. No. 34-2023]
(1) All new construction, including manufactured homes and recreational
vehicles on site 180 days or longer and not fully licensed for highway
use, shall be located landward of the reach of high tide.
(2) The use of fill for structural support of buildings, manufactured
homes or recreational vehicles on site 180 days or longer is prohibited.
(3) There shall be no alteration of sand dunes which would increase potential
flood damage. Any disturbance of sand and/or earthen material shall
be conducted in strict compliance with state or local coastal erosion
hazard area regulations.
B. Subdivision and development proposals. The following standards apply
to all new subdivision proposals and other proposed development in
areas of special flood hazard (including proposals for manufactured
home and recreational vehicle parks and subdivisions):
[Amended 11-14-2023 by L.L. No. 34-2023]
(1) Proposals shall be consistent with the need to minimize flood damage;
(2) Public utilities and facilities such as sewer, gas, electrical and
water systems shall be located and constructed so as to minimize flood
damage; and
(3) Adequate drainage shall be provided to reduce exposure to flood damage.
(4) Proposed
development shall not result in physical damage to any other property
(e.g., stream bank erosion or increased flood velocities). If requested
by the Local Administrator, the applicant shall provide a technical
analysis, by a licensed professional engineer, demonstrating that
this condition has been met.
(5) Proposed
development shall be designed, located, and constructed so as to offer
the minimum resistance to the flow of water and shall be designed
to have a minimum effect upon the height of floodwater.
(6) Any
equipment or materials located in a special flood hazard area shall
be elevated, anchored, and floodproofed as necessary to prevent flotation,
flood damage, and the release of hazardous substances.
(7) No
alteration or relocation of a watercourse shall be permitted unless:
(a) A technical evaluation by a licensed professional engineer demonstrates
that the altered or relocated segment will provide conveyance equal
to or greater than that of the original stream segment and will not
result in physical damage to any other property;
(b) If warranted, a conditional revision of the Flood Insurance Rate
Map is obtained from the Federal Emergency Management Agency (FEMA),
with the applicant providing the necessary data, analyses, and mapping
and reimbursing the Town of Southampton for all fees and other costs
in relation to the application; and
(c) The applicant provides assurance that maintenance will be provided
so that the flood-carrying capacity of the altered or relocated portion
of the watercourse will not be diminished.
C. Encroachments.
(1) Within AE Zones on streams without a regulatory floodway, no new
construction, substantial improvements or other development (including
fill) shall be permitted unless:
(a)
The applicant demonstrates that the cumulative effect of the
proposed development, when combined with all other existing and anticipated
development, will not increase the water surface elevation of the
base flood more than one foot at any location; or
(b)
The Town of Southampton agrees to apply to the Federal Emergency
Management Agency (FEMA) for a conditional FIRM revision, FEMA approval
is received and the applicant provides all necessary data, analyses
and mapping and reimburses the Town of Southampton for all fees and
other costs in relation to the application. The applicant must also
provide all data, analyses and mapping and reimburse the Town of Southampton
for all costs related to the final map revision.
(2) On streams with a regulatory floodway, as shown on the Flood Boundary and Floodway Map or the Flood Insurance Rate Map adopted in §
169-6, no new construction, substantial improvements or other development in the floodway (including fill) shall be permitted unless:
(a)
A technical evaluation by a licensed professional engineer shows
that such an encroachment shall not result in any increase in flood
levels during occurrence of the base flood; or
(b)
The Town of Southampton agrees to apply to the Federal Emergency
Management Agency (FEMA) for a conditional FIRM and floodway revision,
FEMA approval is received and the applicant provides all necessary
data, analyses and mapping and reimburses the Town of Southampton
for all fees and other costs in relation to the application. The applicant
must also provide all data, analyses and mapping and reimburse the
Town of Southampton for all costs related to the final map revisions.
(3) In
a special flood hazard area, if any development is found to increase
or decrease base flood elevations, the Town of Southampton shall,
as soon as practicable, but not later than six months after the date
such information becomes available, notify FEMA and the New York State
Department of Environmental Conservation of the changes by submitting
technical or scientific data in accordance with standard engineering
practice.
[Added 11-14-2023 by L.L. No. 34-2023]
D. Zoning district classification. Any land in the area of special flood hazard shall retain the district classification into which it has been placed by Chapter
330, Zoning, but shall additionally be subject to the provisions and requirements of this chapter.
E. Accessory
structures including detached garages. The following standards apply
to new and substantially improved accessory structures, including
detached garages, in the areas of special flood hazard shown on the
Flood Insurance Rate Map.
[Added 11-14-2023 by L.L. No. 34-2023]
(1) The accessory structure must meet the definition of "structure,"
for floodplain management purposes, provided in 44 CFR 59.1, where
"walled and roofed" shall be interpreted as having two outside rigid
walls and a fully secured roof.
(2) The accessory structure should be small, as defined by the community
and approved by FEMA, and represent a minimal investment. Accessory
structures of any size may be considered for a variance; however,
FEMA considers accessory structures that meet the following criteria
to be small and therefore not necessarily in need of a variance, if
the community chooses to allow it:
(a)
Located in an A Zone (A, AE, A1-A30, AR, A99) and less than
or equal to the size of a one-story, two-car garage.
(b)
Located in a V Zone (V, VE, V1-V30) and less than or equal to
100 square feet.
(3) Accessory structures must be anchored as required in §
169-15A.
(4) The portions of the accessory structure located below BFE plus two
feet of freeboard must be constructed with flood-resistant materials.
(5) Mechanical and utility equipment for the accessory structure must
be elevated or dry floodproofed to or above BFE plus two feet of freeboard.
(6) Within Zones AO and Zone A, if base flood elevation data are not
available, areas below three feet above the highest adjacent grade
shall be constructed using methods and practices that minimize flood
damage.
(7) The accessory structure must comply with the floodway encroachment
provisions of the NFIP.
(8) The accessory structure must be wet floodproofed to protect the structure
from hydrostatic pressure. The design must meet the NFIP design and
performance standards for openings per 44 CFR 60.3(c)(5) and must
allow for the automatic entry and exit of floodwaters without manual
operation or the presence of a person (or persons).
(9) Within Zones V1-V30, VE, and V, unelevated accessory buildings must
be unfinished inside, constructed with flood-resistant materials,
and used only for storage. When an accessory building is placed in
these zones, the design professional must determine the effect that
debris from the accessory building will have on nearby buildings.
If the accessory building is large enough that its failure could create
damaging debris or divert flood flows, it must be elevated above the
base flood elevation plus two feet.
[Amended 11-14-2023 by L.L. No. 34-2023}
A. Elevation. The following standards apply to new and substantially improved residential structures located in areas of special flood hazard, in addition to the requirements in §
169-14B, Subdivision and development proposals; §
169-14C, Encroachments; and §
169-15, Standards for all structures:
(1) Within AE Zones new construction and substantial improvements shall have the top of the lowest floor (including basement) elevated to or above two feet above the base flood elevation, as identified by the Flood Insurance Rate Map (FIRM) for the Town of Southampton as established in §
169-6.
(2) For enclosed areas below the lowest floor of a structure within AE
Zones new and substantially improved structures shall have fully enclosed
areas below the lowest floor that are used solely for the parking
of vehicles, building access or storage in an area other than a basement
and that are subject to flooding 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 licensed professional engineer or architect
or 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 foot of enclosed area subject to flooding;
and
(b)
The bottom of all such openings no higher than one foot above
the lowest adjacent finished grade.
(c)
Openings may equipped with louvers, valves, screens or other
coverings or devices, provided they permit the automatic entry and
exit of floodwaters. Enclosed areas subgrade on all sides are considered
basements and are not permitted.
(3) Within Zone A, when no base flood elevation data are available, a
base flood elevation shall be determined by either:
(a)
Obtain and reasonably use data available from a federal, state,
or other source plus two feet of freeboard; or
(b)
Determine the base flood elevation in accordance with accepted
hydrologic and hydraulic engineering practice, plus two feet of freeboard.
Determinations shall be undertaken by a registered design professional
who shall document that the technical methods used reflect currently
accepted engineering practice. Studies, analyses, and computations
shall be submitted in sufficient detail to allow thorough review and
approval.
[Amended 11-14-2023 by L.L. No. 34-2023]
The following standards, in addition to the standards in §
169-14A, coastal high-hazard areas and Coastal A Zones, §
169-14B, Subdivision and development proposals, and §
169-15, Standards for all structures, apply to new and substantially improved residential structures located in areas of special flood hazard shown as VE and Coastal A Zones:
A. Elevation. New construction and substantial improvements shall be elevated on pilings, columns or shear walls such that the bottom of the lowest horizontal structural member supporting the lowest elevated floor (excluding columns, piles, diagonal bracing attached to the piles or columns, grade beams, pile caps and other members designed to either withstand storm action or break away without imparting damaging loads to the structure) is elevated to or above two feet above base flood elevation so as not to impede the flow of water, as identified in the Flood Insurance Rate Map (FIRM) for the Town of Southampton as established in §
169-6.
B. Determination of loading forces. Structural design shall consider
the effects of wind and water loads acting simultaneously during the
base flood on all building components.
(1) The structural design shall be adequate to resist water forces that
would occur during the base flood. Horizontal water loads considered
shall include inertial and drag forces of waves, current drag forces,
and impact forces from waterborne storm debris. Dynamic uplift loads
shall also be considered if bulkheads, walls, or other natural or
man-made flow obstructions could cause wave runup beyond the elevation
of the base flood.
(2) Buildings shall be designed and constructed to resist the forces
due to wind pressure. Wind forces on the superstructure include windward
and leeward forces on vertical walls, uplift on the roof, internal
forces when openings allow wind to enter the house, and upward force
on the underside of the house when it is exposed. In the design, the
wind should be assumed to blow potentially from any lateral direction
relative to the house.
(3) Wind loading values used shall be those required by the Building
Code.
C. Foundation standards.
(1) The pilings or column foundation and structure attached thereto shall
be adequately anchored to resist flotation, collapse or lateral movement
due to the effects of wind and water pressure acting simultaneously
on all building components. Foundations must be designed to transfer
safely to the underlying soil all loads due to wind, water, dead load,
live load and other loads (including uplift due to wind and water).
(2) Spread footings and fill material shall not be used for structural
support of a new building or substantial improvement of an existing
structure.
D. Pile foundation design.
(1) Pile spacing. The design ratio of pile spacing to pile diameter shall
not be less than eight to one for individual piles; however, this
would not apply to pile cluster located below the design grade. The
maximum center-to-center spacing of wood piles shall not be more than
12 feet on center under load-bearing sills, beams or girders.
(2) Pile embedment. Piles shall have adequate soil penetration (bearing
capacity) to resist the combined wave and wind loads (lateral and
uplift) associated with the base flood acting simultaneously with
typical structure (live and dead) loads and shall include consideration
of decreased resistance capacity caused by erosion of soil strata
surrounding the piles. The minimum penetration for foundation piles
is to an elevation of five feet below mean sea level (msl) datum if
the base flood elevation is +10 msl or less or to at least 10 feet
below mean sea level if the base flood elevation is greater than +10
msl.
(3) Column action. Pile foundation analysis shall also include consideration
of piles in column action from the bottom of the structure to the
stable soil elevation of the site. Pilings may be horizontally or
diagonally braced to withstand wind and water forces.
(4) The minimum acceptable sizes for timber piles are a top diameter
of eight inches for round timber piles and eight inches by eight inches
for square timber piles. All wood piles must be treated in accordance
with the requirements of AWPA-C3 to minimize decay and damage from
fungus.
(5) Reinforced concrete piles shall be cast of concrete having a twenty-eight-day
ultimate compressive strength of not less than 5,000 pounds per square
inch and shall be reinforced with a minimum of four longitudinal steel
bars having a combined area of not less than 1% nor more than 4% of
the gross concrete area. Reinforcement for precast piles shall have
a complete cover of not less than 1 1/4 inches for No. 6 through
No. 11 bars. Reinforcement for piles cast in the field shall have
a concrete cover of not less than two inches.
(6) Pile installation. Piles shall be driven by means of a pile driver
or drop hammer, jetted or augured into place.
(7) Bracing. Additional support for piles in the form of bracing may
include lateral or diagonal bracing between piles.
(8) When necessary, piles shall be braced at the ground line in both
directions by a wood timber grade beam or a reinforced concrete grade
beam. These at-grade supports should be securely attached to the piles
to provide support even if scoured from beneath.
(9) Diagonal bracing between piles, consisting of two-inch by eight-inch
(minimum) members bolted to the piles, shall be limited in location
to below the lowest supporting structural member and above the stable
soil elevation and aligned in the vertical plane along pile rows perpendicular
to the shoreline. Galvanized steel rods (minimum diameter of 1/2 inch)
or cable-type bracing is permitted in any plane.
(10)
Knee braces, which stiffen both the upper portion of a pile
and the beam-to-pile connection, may be used along pile rows perpendicular
and parallel to the shoreline. Knee braces shall be two-by-eight lumber
bolted to the sides of the pile/beam or four-by-four or larger braces
framed into the pile/beam. Bolting shall consist of two five-eighths-inch
galvanized steel bolts (each end) for two-by-eight members or one
five-eighths-inch lag bolt (each end) for square members. Knee braces
shall not extend more than three feet below the elevation of the base
flood.
E. Column foundation design. Masonry piers or poured-in-place concrete
piers shall be internally reinforced to resist vertical and lateral
loads and shall be connected with a movement-resisting connection
to a pile cap or pile shaft.
F. Connectors and fasteners. Galvanized metal connectors, wood connectors
or bolts of size and number adequate for the calculated loads must
be used to connect adjoining components of a structure. Toenailing
as a principal method of connection is not permitted. All metal connectors
and fasteners used in exposed locations shall be steel, hot-dipped
galvanized after fabrication. Connectors in protected interior locations
shall be fabricated from galvanized sheet.
G. Beam to pile connections. The primary floor beams or girders shall
span the supports in the direction parallel to the flow of potential
floodwater and wave action and shall be fastened to the columns of
pilings by bolting, with or without cover plates. Concrete members
shall be connected by reinforcement, if cast in place, or, if precast,
shall be securely connected by bolting or welding. If sills, beams
or girders are attached to wood piling at a notch, a minimum of two
five-eighths-inch galvanized steel bolts or two hot-dipped galvanized
straps 3/16 inch by four inches by 18 inches, each bolted with two
one-half-inch lag bolts per beam member, shall be used. Notching of
pile tops shall be the minimum sufficient to provide ledge support
for beam members not to be notched so that the cross section is reduced
below 50%.
H. Floor and deck connections.
(1) Wood two-inch by four-inch (minimum) connectors or metal joist anchors
shall be used to tie floor joists to floor beams/girders. These should
be installed on alternate floor joints, at a minimum. Cross bridging
of all floor joists shall be provided. Such cross bridging may be
one-inch by three-inch members, placed eight feet on center, maximum,
or solid bridging of same depth as joist at same spacing.
(2) Plywood should be used for subflooring and attic flooring to provide
good torsional resistance in the horizontal plane of the structure.
The plywood should not be less than three-fourths-inch total thickness
and should be exterior grade and fastened to beams or joists with
8d annular or spiral-thread galvanized nails. Such fastening shall
be supplemented by the application of waterproof industrial adhesive
applied to all bearing surfaces.
I. Exterior wall connections. All bottom plates shall have any required
breaks under a wall stud or an anchor bolt. Approved anchors will
be used to secure rafters or joists and top and bottom plates to studs
in exterior and bearing walls to form a continuous tie. Continuous
plywood sheathing 15/32 inch or thicker, overlapping the top wall
plate and continuing down to the sill, beam, or girder, may be used
to provide the continuous tie. If the sheets of plywood are not vertically
continuous, then two-by-four nailer blocking shall be provided at
all horizontal joints. In lieu of the plywood, galvanized steel rods
of 1/2 inch in diameter or galvanized steel straps no less than one
inch wide by 1/16 inch thick may be used to connect from the top wall
plate to the fill, beam, or girder. Washers with a minimum diameter
of three inches shall be used at each end of the one-half-inch-round
rods. These anchors shall be installed no more than two feet from
each corner and no more than four feet on center.
J. Ceiling joist/rafter connection.
(1) All ceiling joists or rafters shall be installed in such a manner
that the joists provide a continuous tie across the rafters. Ceiling
joists and rafters shall be securely fastened at their intersections.
A metal or wood connector shall be used at alternate ceiling joist/rafter
connections to the wall top plate.
(2) Gable roofs shall be additionally stabilized by installing two-by-four
blocking on two-foot centers between the rafters at each gable end.
Blocking shall be installed a minimum of eight feet toward the house
interior from each gable end.
K. Projecting members. All cantilevers and other projecting members
must be adequately supported and braced to withstand wind and water
uplift forces. Larger overhangs and porches will be permitted if designed
or reviewed and certified by a registered professional engineer or
architect.
L. Roof sheathing.
(1) Plywood or other wood material, when used as roof sheathing, shall
not be less than 15/32 inch in thickness and shall be of exterior
sheathing grade or equivalent. All attaching devices for sheathing
and roof coverings shall be galvanized or shall be of other suitable
corrosion-resistant material.
(2) All corners, gable ends, and roof overhangs exceeding six inches
shall be reinforced by the application of waterproof industrial adhesive
applied to all bearing surfaces of any plywood sheet used in the sheathing
of such corner, gable end, or roof overhang.
(3) In addition, roofs should be sloped as steeply as practicable to
reduce uplift pressures, and special care should be used in securing
ridges, hips, valleys, eaves, vents, chimneys, and other points of
discontinuity in the roofing service.
M. Protection of openings. All exterior glass panels, windows, and doors
shall be designed, detailed, and constructed to withstand loads due
to the design wind speed of 120 miles per hour, three-second gust.
Connections for these elements must be designed to transfer safely
the design loads to the supporting structure.
N. Breakaway wall design standards.
(1) The breakaway wall shall have a design safe loading resistance of
not less than 10 and not more than 20 pounds per square foot, with
the criterion that the safety of the overall structure at the point
of all failure be confirmed using established procedures. Grade beams
shall be installed in both directions for all piles considered to
carry the breakaway wall load. Knee braces are required for front
row piles that support breakaway walls.
(2) Use of breakaway wall strengths in excess of 20 pounds per square
foot shall not be permitted unless a registered professional engineer
or architect has developed or reviewed the structural design and specifications
for the building foundation and breakaway wall components and certifies
that the breakaway walls will fail under water loads less than those
that would occur during the base flood and that the elevated portion
of the building and supporting foundation system will not be subject
to collapse, displacement, or other structural damage due to the effects
of wind and water loads acting simultaneously on all building components
(structural and nonstructural). Water loading values used shall be
those associated with the base flood. Wind loading values shall be
those required by the Building Code.
The following standards apply to new and substantially improved commercial, industrial and other nonresidential structures located in areas of special flood hazard, in addition to the requirements in §
169-14B, Subdivision proposals; §
169-14C, Encroachments; and §
169-15, Standards for all structures.
A. Within AE Zones, new construction and substantial improvements of
any nonresidential structure, together with attendant utility and
sanitary facilities, shall either:
(1) Have the lowest floor, including basement or cellar, elevated to
or above two feet above the base flood elevation; or
(2) Be floodproofed so that the structure is watertight below two feet
above the base flood elevation, with walls substantially impermeable
to the passage of water. All structural components located below the
base flood elevation must be capable of resisting hydrostatic and
hydrodynamic loads and the effects of buoyancy.
(3) For enclosed areas below the lowest floor of a structure within AE
Zones new and substantially improved structures shall have fully enclosed
areas below the lowest floor that are usable solely for the parking
of vehicles, building access or storage in an area other than a basement
and that are subject to flooding 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 licensed professional engineer or architect
or 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; and
(b)
The bottom of all such openings no higher than one foot above
the lowest adjacent finished grade.
(c)
Openings may be equipped with louvers, valves, screens or other
coverings or devices, provided they permit the automatic entry and
exist of floodwaters. Enclosed areas subgrade on all sides are considered
basements and are not permitted.
B. If the structure is to be floodproofed, a licensed professional engineer or architect shall develop and/or review structural design, specifications, and plans for construction. A floodproofing certificate or other certification shall be provided to the local administrator that certifies that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of §
169-18A(2), including the specific elevation (in relation to mean sea level) to which the structure is to be floodproofed.
C. Within Zones AH and AO, adequate drainage paths are required to guide
floodwaters around and away from proposed structures on slopes.
D. Within Zone A, when no base flood elevation data are available, the
lowest floor (including basement) shall be elevated at least three
feet above the highest adjacent grade.
[Amended 11-14-2023 by L.L. No. 34-2023]
In VE and Coastal A Zones, new construction and substantial
improvements of any nonresidential structure, together with attendant
utility and sanitary facilities, shall have the bottom of the lowest
member of the lowest floor elevated to or above two feet above the
base flood elevation. Floodproofing of structures is not an allowable
alternative to elevating the lowest floor to two feet above the base
flood elevation in VE and Coastal A Zones.
The following standards, in addition to the standards in §
169-14, General standards, and §
169-15, Standards for all structures, apply, as indicated, in areas of special flood hazard to manufactured homes and to recreational vehicles which are located in areas of special flood hazard.
A. Recreational vehicles.
(1) Recreational vehicles placed on sites within AE and VE Zones shall
either:
(a)
Be on site fewer than 180 consecutive days;
(b)
Be fully licensed and ready for highway use; or
(c)
Meet the requirements for manufactured homes in §
169-20B.
(2) A recreational vehicle is ready for highway use if it is on its wheels
or a jacking system, is attached to the site only by quick-disconnect-type
utilities and security devices and has no permanently attached additions.
B. A manufactured home that is placed or substantially improved in AE
or VE Zones shall be elevated on a permanent foundation such that
the lowest floor is elevated to or above two feet above the base flood
elevation and is securely anchored to an adequately anchored foundation
system to resist flotation, collapse and lateral movement. Elevation
on piers consisting of dry stacked blocks is prohibited.