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 § 42-6.
A. 
Coastal high hazard areas and Coastal A Zones. The following requirements apply within Zones V1 through 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 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):
(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 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, with the applicant providing the necessary data, analyses, and mapping and reimbursing the City of North Tonawanda 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 Zones A1 through 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 City of North Tonawanda 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 City of North Tonawanda for all fees and other costs in relation to the application. The applicant must also provide all data, analyses and mapping and reimburse the City of North Tonawanda 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 § 42-6, 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 demonstrates through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that such an encroachment shall not result in any increase in flood levels during occurrence of the base flood; or
(b) 
The City of North Tonawanda 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 City of North Tonawanda for all fees and other costs in relation to the application. The applicant must also provide all data, analyses and mapping and reimburse the City of North Tonawanda for all costs related to the final map revisions.
(3) 
In a special flood hazard area (SFHA), if any development is found to increase or decrease base flood elevations, the City of North Tonawanda 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.
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 § 42-6.
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 Zones A1 through A30, AE, AO or A, new and substantially improved structures shall have fully enclosed areas below the lowest floor that are useable 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:
(a) 
A minimum of two openings 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; and
(b) 
The bottom of all such openings no higher than one foot above grade.
(c) 
Openings not less than three inches in any direction.
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 through V30 and VE, and also within Zone V if base flood elevation data are available, 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 lattice-work 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 are 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 or designed to prevent water from entering and accumulating within the components 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.
D. 
Storage tanks.
(1) 
Underground tanks shall be anchored to prevent flotation, collapse and lateral movement during conditions of the base flood.
(2) 
Aboveground tanks shall be:
(a) 
Anchored to prevent flotation, collapse or lateral movement during conditions of the base flood; or
(b) 
Installed at or above the base flood elevation as shown on the Flood Insurance Rate Map enumerated in § 42-6 plus two feet.
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 § 42-15B, Subdivision proposals, § 42-15C, Encroachments, and § 42-16, Standards for all structures.
(1) 
Within special flood hazard areas (SFHAs) if base flood elevation data are available, 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.
(2) 
Within Zone A, when no base flood elevation data are available, a base flood elevation shall be determined by either:
(a) 
Obtaining and reasonably using data available from a federal, state, or other source plus two feet of freeboard; or
(b) 
Determining 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.
(3) 
Within Zone AO, new construction and substantial improvements shall 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 Flood Insurance Rate Map enumerated in § 42-6 plus two feet of freeboard.
(4) 
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 § 42-15A, Coastal high hazard areas and Coastal A Zones, § 42-15B, Subdivision proposals, and § 42-16, Standards for all structures, apply to new and substantially improved residential structures located in areas of special flood hazard shown as Zones V1 through V30, VE or V on the community's Flood Insurance Rate Map designated in § 42-6.
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-inch-by-eight-inch lumber bolted to the sides of the pile/beam, or four-inch-by-four-inch or larger braces framed into the pile/beam. Bolting shall consist of two 5/8-inch galvanized steel bolts (each end) for two-inch-by-eight-inch members, or one 5/8 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 5/8-inch galvanized steel bolts or two hot-dipped galvanized straps 3/16 inch by four inches by 18 inches each bolted with two 1/2-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-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 joists, at a minimum. Cross bridging of all floor joists shall be provided. Such cross bridging may be three-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 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 2-by-4 nailer blocking shall be provided at all horizontal joints. In lieu of the plywood, galvanized steel rods of 1/2 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 1/2-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 2-by-4 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 mph. 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 (1) the breakaway walls will fail under water loads less than those that would occur during the base flood; and (2) 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 § 42-15B, Subdivision proposals, § 42-15C, Encroachments, and § 42-16, Standards for all structures.
A. 
Within Zones A1 through 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, including attendant utility and sanitary facilities, 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 the depth number specified in feet on the community's FIRM plus two feet (at least three 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 § 42-19A(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 the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of § 42-19A(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.
A. 
In Zones V1 through 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 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 through V30, VE and V.
The following standards in addition to the standards in §§ 42-15, General standards, and 42-16, 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 A, A1 through A30, AE, AH, AO, V1 through 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 § 42-21B, 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 through A30, AE, and AH shall be elevated on a permanent foundation such that the bottom of the frame of the manufactured home chassis 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, when no base flood elevation data are available, a base flood elevation shall be determined by either:
(1) 
Obtain and reasonably use data available from a federal, state, or other source plus two feet of freeboard; or
(2) 
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.
Elevation on piers consisting of dry stacked blocks is prohibited.
D. 
Within Zone AO, the bottom of the frame of the manufactured home chassis 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 § 42-6 plus two feet (at least three feet if no depth number is specified). Elevation on piers consisting of dry stacked blocks is prohibited.
E. 
Within Zones V or VE, manufactured homes must meet the requirements of § 42-18.
F. 
The foundation and anchorage of manufactured homes to be located in identified floodways shall be designed and constructed in accordance with ASCE 24.
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 designated in § 42-6.
A. 
Within Zones A1 through A30, AE, AO, AH, A, accessory structures must meet the standards of § 42-16A, Anchoring.
B. 
Within Zones A1 through A30, AE and AH, and also Zone A if base flood elevation data are available, areas below two feet above the base flood elevation shall be constructed using methods and practices that minimize flood damage.
C. 
Within Zones AO and 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.
D. 
Structures must be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters in accordance with § 42-16C, Utilities.
E. 
Within Zones V1 through V30, VE, and V, accessory structures (unless properly elevated to the base flood elevation plus two feet on piles or columns) must be limited to small, low-value structures that are disposable. If a community wishes to allow unelevated accessory buildings, it must define "small" and "low cost."
F. 
Within Zones V1 through V30, VE, and V, unelevated accessory buildings must be unfinished inside, constructed with flood-resistant materials, and used only for storage.
G. 
Within Zones V1 through V30, VE, and V, when an accessory building is placed, 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.