(A) Residential construction. New construction or substantial improvement of any structure (or manufactured home) shall have the lowest floor, including basement, elevated not lower than one foot above the minimum base flood elevation requirement. Historical structures individually listed on the town Historical Resources List as a Traditional Island Resource or a Landmark Structure that has not been substantially improved after December 1977 is exempt from the one-foot freeboard requirement.
(1) In A, AE, or AO Zones an enclosed storage area not to exceed 200 square feet in area is allowed below the base flood elevation, provided the walls forming the enclosure is certified by a registered professional engineer or architect as breakaway construction and contain vents to equalize hydrostatic flood forces as described in this division (A) and divisions (B) and (C) below.
(2) All other space below the regulatory flood elevation shall be open lattice or mesh screening. Open lattice may incorporate a lightweight transparent material on the inside of the lattice panel provided the walls forming the enclosure is certified by a registered professional engineer or architect as breakaway construction and contain vents to equalize hydrostatic flood forces as described in division (C) below. A non-conversion agreement must be signed, notarized, recorded with the deed to the property and submitted to the Administrator. This agreement will allow yearly inspection of the area below base flood for compliance with the Flood Damage Prevention Ordinance of the town.
(B) Non-residential construction. New construction or substantial improvement of any commercial, industrial, or non-residential building (or manufactured home) shall have the lowest floor, including basement, elevated no lower than one foot above the base flood elevation. Buildings located in all A Zones may be flood-proofed in lieu of being elevated, provided that all areas of the building below the required elevation are water-tight with walls substantially impermeable to the passage of water, and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall certify that the standards of this division (B) are satisfied. Such certification shall be provided to the official as set forth in § 153.27(I).
(C) Elevated buildings. New construction of elevated buildings shall meet the requirements as set forth in division (A) above. Substantial improvements of elevated buildings that include existing fully enclosed areas formed by foundation and other exterior walls below the base flood elevation shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwater to automatically equalize hydrostatic flood forces on exterior walls.
(1) Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:
(a) Provide 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;
(b) The bottom of all openings shall be no higher than one foot above grade; and
(c) Openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic flow of floodwater in both directions.
(2) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator); and
(3) The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.
(D) Standards for areas of shallow flooding (AO Zones).Located within the areas of special flood hazard established in this chapter, are areas designated as shallow flooding. The following provisions shall apply within such areas.
(1) All new construction and substantial improvements of residential structures shall have the lowest floor elevated to at least as high as the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor shall be elevated at least three feet above the highest adjacent grade; and
(2) All new construction and substantial improvements of non-residential structures shall:
(a) Have the lowest floor elevated to at least as high as the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor shall be elevated at least three feet above the highest adjacent grade.
(b) Be completely flood-proofed together with attendant utility and sanitary facilities to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Certification is required as stated in this chapter.
(E) Standards for manufactured homes and recreational vehicles.
(1) All manufactured homes placed, or substantially improved, on individual lots or parcels, must meet all the requirements for new construction, including elevation and anchoring.
(a) The lowest floor of the manufactured home is elevated no lower than the base flood elevation, or the manufactured home chassis is supported by reinforced piers or other foundation elements of at least an equivalent strength, of no less than 36 inches in height above grade.
(b) The manufactured home must be securely anchored to the adequately anchored foundation system to resist flotation, collapse and lateral movement.
(c) When existing manufactured home has incurred “substantial damage” as the result of a flood, any manufactured home placed or substantially improved must meet the standards of divisions (D)(2)(a) and (D)(2)(c) below.
(2) All recreational vehicles placed on sites must either:
(a) Be fully licensed and ready for highway use (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 structures); or
(b) The recreational vehicle must meet all the requirements for new construction, including anchoring and elevation requirements of this division (D)(2) or division (D)(1) above.
(F) Coastal high hazard areas (V Zones). Located within the areas of special flood hazard established in § 153.07, are areas designated as coastal high hazard areas. These areas have special flood hazards associated with wave wash, therefore, the following provisions shall apply.
(1) All buildings shall be located landward of the reach of the mean high tide.
(2) All buildings shall be elevated so that the bottom of the lowest supporting horizontal member (excluding pilings or columns) is located no lower than the base flood elevation level. An enclosed storage area not to exceed 200 square feet in area is allowed below the base flood elevation, provided the walls forming the enclosure are certified by a registered professional engineer or architect as breakaway construction and contain vents to equalize hydrostatic flood forces as described in division (C) above. Further enclosure consisting of open lattice work or decorative screening may be permitted for aesthetic purposes only and must be designed to wash away in the event of abnormal wave action and in accordance with division (E)(8) below.
(3) All buildings or structures shall be securely anchored on pilings or columns.
(4) All pile and column foundations and structures attached thereto shall be anchored to resist flotation, collapse and lateral movement due to the effect of wind and water loads acting simultaneously on all building components. Water loading values shall equal or exceed the base flood. Wind loading values shall be in accordance with the most current edition of International Building Code.
(5) A registered professional engineer or architect shall certify that the design, specifications and plans for construction are in compliance with the provisions contained in divisions (E)(2), (E)(3) and (E)(4) above.
(6) There shall be no fill used as structural support. Non-compacted fill may be used around the perimeter of a building for landscaping/aesthetic purposes, provided the fill will wash out from storm surge, (thereby rendering the building free from obstruction) prior to generating excessive loading forces, ramping effects or wave deflection. The Zoning Administrator shall approve design plans for landscaping/aesthetic fill only after the applicant has provided a analysis by an engineer, architect and/or soil scientist, which demonstrates that the following factors have been fully considered:
(a) Particle composition of fill material does not have a tendency for excessive natural compaction;
(b) Volume and distribution of fill will not cause wave defection to adjacent properties; and
(c) Slope of fill will not cause wave run-off or ramping.
(7) There shall be no alteration of sand dunes which would increase potential flood damage.
(8) In addition to the enclosed storage area mentioned in division (E)(2) above, open lattice work or mesh screening shall be allowed below the base flood elevation, provided they are not part of the structural support of the building and are designed to breakaway under abnormally high tides or wave action without damage to the structural integrity of the building on which they are to be used, and provided the following design specifications are met:
(a) No additional solid walls shall be allowed; and
(b) Material shall consist of lattice or mesh screening only.
(9) If aesthetic lattice work or screening is utilized, such enclosed space shall not be designed to be used for human habitation, but shall be designed to be used only for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises.
(10) Prior to construction, plans for any buildings that will have lattice work or decorative screening must be submitted to the Zoning Administrator for approval.
(11) Any alteration, repair, reconstruction or improvement to a structure shall not enclose the space below the lowest floor except with lattice work or decorative screening, as provided for in divisions (E)(8) and (E)(9) above.
(12) Prohibit the placement of manufactured homes (mobile homes), except in an existing manufactured homes (mobile homes) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision, provided the anchoring standards of division (E)(5) above and the elevation standards of division (E)(2) above are met.
(13) All recreational vehicles placed on sites must either:
(a) Be fully licensed and ready for highway use (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 structures); or
(b) The recreational vehicle must meet all the requirements for new construction, including anchoring and elevation requirements of divisions (D)(1) or (D)(2) above.
(Prior Code, § 5-81) (Ord. passed 11-16-2010)