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 §
61-6.
A. Coastal high-hazard areas. The following requirements
apply within Zones V1-V30, VE and V:
(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.
(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 Village of Brightwaters 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 Village
of Brightwaters for all fees and other costs in relation to the application.
The applicant must also provide all data, analyses and mapping and
reimburse the Village of Brightwaters 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 §
61-6, 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 Village of Brightwaters 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
Village of Brightwaters for all fees and other costs in relation to
the application. The applicant must also provide all data, analyses
and mapping and reimburse the Village of Brightwaters for all costs
related to the final map revisions.
[Amended 6-1-2009 by L.L.
No. 6-2009]
The following standards, in addition to the standards in §§
61-15A, Coastal high-hazard areas; 61-15B, Subdivision proposals; and 61-16, Standards for all structures, apply to new and substantially improved residential structures located in areas of special flood hazard shown as Zones V1-V30, VE or V on the community's Flood Insurance Rate Map designated in §
61-6.
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 the level
of the base flood 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 eight to one 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-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-four 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-eights-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 be connected with a moment-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.
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. 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 (if 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 2 1/2 inch lag bolts per beam member shall be used. Nothing
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 the same depth as the joist at the 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 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. 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 by a registered professional engineer or architect and certified in accordance with §
61-13J of this chapter.
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. 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, in addition to the requirements in §§
61-15B, Subdivision proposals; 61-15C, Encroachments; and 61-16, 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 the base flood elevation; or
(2) Be floodproofed so that the structure is watertight
below the base flood level with walls substantially impermeable to
the passage of water. All structural components located below the
base flood level 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 the depth number
specified in feet on the community's FIRM (at least two feet if no
depth number is specified); or
(2) Together with attendant utility and sanitary facilities, be completely floodproofed to that level to meet the floodproofing standard specified in Subsection
A(2).
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 that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of Subsection
A(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 flood waters around and away from proposed structured
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, 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 the base flood elevation. Floodproofing
of structures is not an allowable alternative to elevating the lowest
floor to the base flood elevation in Zones V1-V30, VE and V.
The following standards in addition to the standards in §§
61-15, General standards, and 61-16, Standards for all structures, apply 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 Zones
A1-A30, AE, AH, V1-V30, V and VE 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 Subsections
B,
D and
E.
(2) 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 or VE that is on a site either
outside of an existing manufactured home park or subdivision as herein
defined; in a new manufactured home park or subdivision as herein
defined; in an expansion to an existing manufactured home park or
subdivision as herein defined; or in an existing manufactured home
park or subdivision as herein defined on which a manufactured home
has incurred substantial damage as the result of a flood shall, within
Zones A1-A30, AE and AH, be elevated on a permanent foundation such
that the lowest floor is elevated to or above the base flood elevation
and is securely anchored to an adequately anchored foundation system
to resist flotation, collapse and lateral movement; or, within Zones
V1-V30 and VE, be elevated on a pile foundation such that the bottom
of the lowest structural member of the lowest floor (excluding pilings
and columns) is elevated to or above the base flood elevation and
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. Methods of anchoring may include
but are not limited to use of over-the-top or frame ties to ground
anchors.
C. A manufactured home to be placed or substantially
improved in Zone A1-A30, AE, AH, V1-V30 or VE in an existing manufactured
home park or subdivision that is not to be placed on a site on which
a manufactured home has incurred substantial damage shall be:
(1) Elevated in a manner such as required in Subsection
B; or
(2) 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 Zones 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 the lowest
adjacent 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.
E. 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 §
61-6 (at least two feet if no depth number is specified). Elevation on piers consisting of dry stacked blocks is prohibited.