The following standards apply to new development, including new and substantially improved structures, in the areas of special flood hazard shown on the Flood Insurance Rate Map designated in § 168-6.
A.
Coastal high hazard areas. The following requirements apply within
Zones V1-V30, VE and V or in an area of moderate wave action:
(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)
Man-made alteration of sand dunes which would increase potential
flood damage is prohibited.
B.
Subdivision 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):
(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.
C.
Encroachments.
(1)
Within Zones A1-A30 and AE, 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 Smithtown 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 Smithtown 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 Smithtown
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 § 168-6, 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 Smithtown 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 Smithtown 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 Smithtown for all costs related to the final map revisions.
A.
Anchoring. New structures and substantial improvement to structures
in areas of special flood hazard shall be anchored to prevent flotation,
collapse, or lateral movement during the base flood. This requirement
is in addition to applicable state and local anchoring requirements
for resisting wind forces.
B.
Construction materials and methods.
(1)
New construction and substantial improvements to structures shall
be constructed with materials and utility equipment resistant to flood
damage.
(2)
New construction and substantial improvements to structures shall
be constructed using methods and practices that minimize flood damage.
(3)
For enclosed areas below the lowest floor of a structure within Zone
A1-A30, AE or AH, and also Zone A if base flood elevation data are
available, new and substantially improved structures shall have 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, 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: (i) 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 (ii)
the bottom of all such openings no higher than one foot above the
lowest adjacent finished grade. Openings may be 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.
(4)
Within Zones V1-V30 and VE, and also within Zone V if base flood
elevation are available, or in an area of moderate wave action, new
construction and substantial improvements shall have the space below
the lowest floor either free from obstruction or constructed with
nonsupporting breakaway walls, open wood latticework or insect 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. The enclosed space below
the lowest floor shall be used only for parking vehicles, building
access or storage. Use of this space for human habitation is expressly
prohibited. The construction of stairs, stairwells and elevator shafts
is subject to the design requirements for breakaway walls.
C.
Utilities.
(1)
New and replacement electrical equipment, heating, ventilating, air
conditioning, plumbing connections, and other service equipment shall
be located at least two feet above the base flood elevation or be
designed to prevent water from entering and accumulating within the
components during a flood and to resist hydrostatic and hydrodynamic
loads and stresses. Electrical wiring and outlets, switches, junction
boxes and panels shall be elevated to or above the base flood elevation
unless they conform to the appropriate provisions of the electrical
part of the Building Code of New York State or the Residential Code
of New York State for location of such items in wet locations;
(2)
New and replacement water supply systems shall be designed to minimize
or eliminate infiltration of floodwaters into the system;
(3)
New and replacement sanitary sewage systems shall be designed to
minimize or eliminate infiltration of floodwaters. Sanitary sewer
and storm drainage systems for buildings that have openings below
the base flood elevation shall be provided with automatic backflow
valves or other automatic backflow devices that are installed in each
discharge line passing through a building's exterior wall; and
(4)
On-site waste disposal systems shall be located to avoid impairment
to them or contamination from them during flooding.
The following standards apply to new and substantially improved residential structures located in areas of special flood hazard, in addition to the requirements in § 168-22B, Subdivision proposals, and § 168-22C, Encroachments, and § 168-23, Standards for all structures.
A.
Within Zones A1-A30, AE and AH, and also Zone A if base flood elevation
data are available, new construction and substantial improvements
shall have the lowest floor (including basement) elevated to or above
two feet above the base flood elevation.
B.
Within Zone A, when no base flood elevation data are available, new
and substantially improved structures shall have the lowest floor
(including basement) elevated at least three feet above the highest
adjacent grade.
C.
Within Zone AO, new and substantially improved structures shall have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as two feet above the depth number specified in feet on the community's Flood Insurance Rate Map enumerated in § 168-6 (at least two feet if no depth number is specified).
D.
Within Zones AH and AO, adequate drainage paths are required to guide
floodwaters around and away from proposed structures on slopes.
The following standards, in addition to the standards in § 168-22A, Coastal high hazard areas, and § 168-22B, Subdivision proposals, and § 168-23, Standards for all structures, apply to new and substantially improved residential structures located in areas of special flood hazard shown as Zone V1-V30, VE or V or in an area of moderate wave action, on the community's Flood Insurance Rate Map designated in § 168-6.
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.
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 pressures 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)
The design ratio of pile spacing to pile diameter shall not be less
than 8:1 for individual piles (this shall not apply to pile clusters
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)
Pilings 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 BFE is +10 msl or less,
or to be at least 10 feet below msl if the BFE is greater than +10
msl.
(3)
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 tip 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 requirements of EPEE-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. Reinforcing for precast piles shall
have a concrete cover of not less than 1 1/4 inches for No. 5
bars and smaller and not less than 1 1/2 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)
Piles shall be driven by means of a pile driver or drop hammer, jetted,
or augered into place.
(7)
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
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.
(1)
Masonry piers or poured-in-place concrete piers shall be internally
reinforced to resist vertical and lateral loads, and be connected
with a movement-resisting connection to a pile cap or pile shaft.
F.
Connectors and fasteners.
(1)
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. Toe nailing 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.
(1)
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 or pilings by bolting, with or
without cover plates. Concrete members shall be connected by reinforcement,
if cast in place, or (of precast) shall be securely connected by bolting
and 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 without unduly weakening
pile connections. Piling shall not be notched so that the cross-section
is reduced below 50%.
H.
Floor and deck connections.
(1)
Wood two-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 joists, at a minimum. Cross-bridging
of all floor joists shall be provided. Such cross-bridging may be
one-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 3/4 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.
(1)
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 15/32-inch or thicker plywood
sheathing, 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 one-half-inch diameter or
galvanized steel straps not less than one inch wide by 1/16 inch thick
may be used to connect from the top wall plate to the sill, 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 rod, no more than
four feet on center.
J.
Ceiling joist/rafter connections.
(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.
(1)
All cantilevers and other projecting members must be adequately supported
and braced to withstand wind and water uplift forces. Roof eave overhangs
shall be limited to a maximum of two feet and joist overhangs to a
maximum of one foot. 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 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 surface.
M.
Protection of openings.
(1)
All exterior glass panels, windows, and doors shall be designed,
detailed, and constructed to withstand loads due to the design wind
speed of 75 miles per hour. Connections for these elements must be
designed to transfer safely the design loads to the supporting structure.
Panel widths of multiple-panel sliding glass doors shall not exceed
three feet.
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 wall 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 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 § 168-22B, Subdivision proposals, and § 168-22C, Encroachments, and § 168-23, Standards for all structures.
A.
Within Zones A1-A30, AE and AH, and also Zone A if base flood elevation
data are available, 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.
B.
Within Zone AO, new construction and substantial improvements of
nonresidential structures shall:
(1)
Have the lowest floor (including basement) elevated above the highest
adjacent grade at least as high as two feet above the depth number
specified in feet on the community's FIRM (at least two feet
if no depth number is specified); or
C.
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 the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of § 168-26A(2), including the specific elevation (in relation to mean sea level) to which the structure is to be floodproofed.
D.
Within Zones AH and AO, adequate drainage paths are required to guide
floodwaters around and away from proposed structures on slopes.
E.
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.
In Zones V1-V30, VE, and also Zone V if base flood elevations
are available, or in an area of moderate wave action, new construction
and substantial improvements of any nonresidential structure, together
with attendant utility and sanitary facilities, shall have the bottom
of 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 Zones V1-V30, VE and V.
The following standards, in addition to the standards in § 168-22, General standards, and § 168-23, 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 placed on sites within Zones A1-A30, AE, AH, V1-V30, V, and VE shall either: (1) be on site fewer than 180 consecutive days, (2) be fully licensed and ready for highway use, or (3) meet the requirements for manufactured homes in § 168-28B, C, and D. A recreational vehicle is ready for highway use if it is on its wheels or 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 Zones
A1-A30, AE, AH, V1-V30, V, and VE 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.
C.
Within Zone A or V, when no base flood elevation data are available,
new and substantially improved manufactured homes shall be elevated
such that 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 are securely
anchored to an adequately anchored foundation system to resist flotation,
collapse or lateral movement. Elevation on piers consisting of dry
stacked blocks is prohibited.
D.
Within Zone AO, the floor shall be elevated above the highest adjacent grade at least as high as the depth number specified on the Flood Insurance Rate Map enumerated in § 168-6 (at least two feet if no depth number is specified). Elevation on piers consisting of dry stacked blocks is prohibited.
