(A) All new construction and substantial improvements within the areas of special flood hazard shall comply with the following:
(1) Be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy and debris impact.
(2) Be constructed to meet or exceed the required design flood elevation (DFE), which is the base flood elevation plus a two-foot freeboard.
(3) When proposed new construction and substantial improvements are partially located in an area of special flood hazard, the entire structure shall meet the standards for new construction.
(4) When proposed new construction and substantial improvements are located in multiple flood hazard risk zones or in a flood hazard risk zone with multiple base flood elevations, the entire structure shall meet the standards for the most hazardous flood hazard risk zone and the highest base flood elevation.
(5) Be constructed with Class 4 or 5 materials resistant to flood damage as per FEMA Technical Bulletin 2, entitled “Flood-Resistant Materials Requirements for Buildings Located in Special Flood Hazard Areas”, incorporated herein by reference, in all areas below the design flood elevation,
(6) Be constructed by methods and practices that minimize potential for flood damages.
(7) A temporary construction trailer may only be permitted to be on site for fewer than 180 consecutive calendar days at a time, and must be fully ready for highway use, and shall be attached to the site only by quick disconnect type utilities and security devices.
(8) Electrical, ventilation, plumbing, heating and air conditioning equipment (including ductwork), and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of the base flood plus two feet (freeboard).
(9) Be constructed with methods and practices outlined in ASCE24 or an at least equally stringent standard.
(B) Elevation certificate requirements when a structure is constructed or substantially improved in the area of special flood hazard:
(1) A certified under construction elevation certificate is required, after the lowest floor is completed and before any further inspections are accepted and vertical construction commences.
(2) Floodproofing certificate for non-residential construction including floodproofing level is required immediately after the floodproofing is completed. When floodproofing is utilized for non-residential structures, said certification shall be prepared by or under the direct supervision of a professional engineer or architect and certified by same.
(3) A certified finished construction elevation certificate shall be provided after completion of construction including final grading of the site.
(4) Elevation certificates shall be prepared by or under the direct supervision of a registered land surveyor or professional engineer and certified by same.
(5) Any work undertaken prior to approval of these certifications shall be at the permit holder’s risk. The Building Official shall review the above referenced certification data submitted. Deficiencies detected by such review shall be corrected by the permit holder immediately and prior to further work being allowed to proceed.
(6) Failure to submit certification or failure to make the corrections required hereby shall be cause to issue a stop work order for the project and/or the certificate of occupancy may be withheld.
(C) New development in the area of special flood hazard shall minimize disruption to shorelines, stream channels, stream banks, and the regulatory floodway.
(D) (1) Water supply systems: All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
(2) Sanitary sewage systems: New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into floodwaters. On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
(E) Existing buildings and structures:
(1) Where substantial improvement or substantial damage is not a factor, replacement of electrical, heating, plumbing, heating and air conditioning equipment to existing structures shall be elevated to at least the existing lowest floor level or to the design flood elevation; and replacement ductwork installed below DFE shall be designed so as to prevent water from entering or accumulating within during conditions of flooding.
(2) Improvements to a structure where substantial improvement or substantial damage is not a factor shall be designed and constructed so as to meet the requirements of this chapter, with an exception that the minimum elevation of the lowest floor of an improvement may match the existing legally non-conforming structure existing lowest floor.
(F) Modular construction shall be consistent with the South Carolina Modular Building Construction Act (S.C. Code § 23-43-10 et seq.) as may be amended from time to time, which is incorporated herein by reference.
(G) Enclosures below the design flood elevation, shall be the minimum necessary to allow for parking of vehicles, limited storage, or entry to the living area.
(H) An exterior door with a landing shall be installed at the top of the stairs that provide access to the building.
(I) Accessory residential structure specific standards. New construction or substantial improvements to residential accessory structures that contain habitable space shall meet the requirements of new construction as contained in this chapter. Small and/or low value accessory structures that do not contain habitable space may be exempted from the elevation requirements in AE Zones only, provided the following conditions are met:
(1) The building is constructed of flood-resistant materials below the design flood elevation.
(2) Exterior perimeter walls are provided with openings to relieve hydrostatic pressure and the interior is not partitioned or finished into separate rooms.
(3) Electrical, heating, ventilation, plumbing, air conditioning, and other service facilities are prohibited, except for essential lighting and power circuits. Flood elevation certificates may be required to determine the elevation of electric or other utility services provided to the accessory structure. Service facilities such as electrical and heating equipment shall be elevated or floodproofed to DFE.
(4) Accessory structures shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters. Accessory structures shall be firmly anchored to prevent flotation which may result in damage to other structures.
(5) The building is used only for parking of vehicles and/or limited storage of equipment used to service the principal building.
(J) Manufactured home additional specification standards.
(1) Permits shall be obtained for placement of manufactured homes or temporary construction trailers.
(2) All manufactured homes permitted to be placed shall be installed using methods and practices which minimize flood damage, which include but are not limited to elevating the lowest floor of the manufactured home on a permanent foundation, as defined herein as a MANUFACTURED HOME PERMANENT FOUNDATION, to or above the design flood elevation in A or AE zones only.
(a) For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse, or lateral movement.
(b) Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors.
(c) This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
(d) Designs for manufactured home permanent foundations are subject to approval of the Building Official.
(K) Recreational vehicles additional specific standards. All recreational vehicles, other than those parked at another permanent structure temporarily while not in use, place or sited within special flood hazard areas must:
(1) Be on the site for fewer than 180 consecutive calendar days, and
(2) Be fully registered 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 additions.
(3) If the vehicle is to remain in an A or AE zone, it must be elevated in accordance with requirements for manufactured homes as provided in § 151.41.
(Ord. 2016-14, passed 1-19-2017; Ord. 2018-12, passed 10-18-2018; Ord. 2020-11, passed 12-17-2020)