a. All new construction and substantial improvements shall be located landward of the reach of mean high tide, first line of stable natural vegetation and comply with all applicable Department of Health and Environmental Control (DHEC) Ocean and Coastal Resource Management (OCRM) setback requirements.
b. All new construction and substantial improvements shall be elevated so that the bottom of the lowest supporting horizontal structural member (excluding pilings or columns) of the lowest floor is located no lower than one foot above the base flood elevation.
c. All buildings or structures shall be securely anchored on pilings or columns, extending vertically below a grade of sufficient depth and the zone of potential scour, and securely anchored to the subsoil strata.
d. All pilings and columns and the attached structures shall be anchored to resist flotation, collapse, lateral movement and scour due to the effect of wind and water loads acting simultaneously on all building components.
e. 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 c. and d. above and divisions f. and i. below.
f. 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 of obstruction prior to generating excessive loading forces, ramping effects or wave deflection. Only beach compatible sand may be used. The Local Floodplain Administrator shall approve design plans for landscaping/aesthetic fill only after the applicant has provided an analysis by an engineer, architect and/or soil scientist that demonstrates that the following factors have been fully considered:
1. Particle composition of fill material does not have a tendency for excessive natural compaction;
2. Volume and distribution of fill will not cause wave deflection to adjacent properties; and
3. Slope of fill will not cause wave run-up or ramping.
g. There shall be no alteration of sand dunes that would increase potential flood damage.
h. 1. All new construction and substantial improvements have the space below the lowest floor either free of obstruction or constructed with non-supporting 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. For the purpose of this section, a breakaway wall shall have a design safe loading resistance of not less than ten and no more than 20 pounds per square foot. Breakaway wall enclosures shall not exceed 299 square feet. Only flood-resistant materials shall be used below the required flood elevation specified in § 19.402. One wet location switch and/or outlet connected to a ground fault interrupt breaker may be installed below the required lowest floor elevation specified in § 19.402.
2. Use of breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot may be permitted only if a registered professional engineer or architect certifies that the designs proposed meet the following conditions:
(a) Breakaway wall collapse shall result from water load less than that which would occur during the base flood.
(b) The elevated portion of the building and supporting foundation system shall 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). The water loading shall be those values associated with the base flood. The wind loading values shall be those required by applicable IBC International Building Code.
(c) Such enclosed space shall be useable solely for parking of vehicles, building access or storage. Such space shall not be used for human habitation, finished or partitioned into multiple rooms or temperature-controlled.
i. No manufactured homes shall be permitted except in an existing manufactured home park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision provided the anchoring and elevation standards of § 19.402c.
j. Recreational vehicles shall be permitted in coastal high hazard areas provided that they meet the recreational vehicle criteria of § 19.402f. and the temporary structure provisions of division k. below.
k. Accessory structures, below the required lowest floor elevation specified in division b. above, are prohibited except for the following.
1. Swimming pools:
(a) Are installed at-grade or elevated so long as the pool will not act as an obstruction;
(b) Must be structurally independent of the building and its foundation;
(c) May be placed beneath a coastal building only if the top of the pool and any accompanying decking or walkway are flush with the existing grade and only if the lower area remains unenclosed; and
(d) As part of the certification process for V-Zone buildings, the design professional must consider the effects that any of these elements will have on the building in question and any nearby buildings.
2. Access stairs attached to or beneath an elevated building:
(a) Must be constructed of flood-resistant materials; and
(b) Must be constructed as open staircases so they do not block flow under the structure in accordance with division b. above.
3. Decks.
(a) If the deck is structurally attached to a building, then the bottom of the lowest horizontal member must be at or above the elevation of the buildings lowest horizontal member.
(b) If the deck is to be built below the BFE, then it must be structurally independent of the main building and must not cause an obstruction.
(c) If an at-grade, structurally independent deck is proposed, then a design professional must evaluate the design to determine if it will adversely affect the building and nearby buildings.
l. Parking areas should be located on a stable grade under or landward of a structure. Any parking surface shall consist of gravel or aggregate.
m. 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 base flood event plus one foot. This requirement does not exclude the installation of outdoor faucets for shower heads, sinks, hoses and the like, as long as cut off devices and back flow prevention devices are installed to prevent contamination to the service components and thereby minimize any flood damages to the building. No utilities or components shall be attached to breakaway walls.
(Ord. 2017-05, passed 12-4-2017)