§ 156.067 STANDARDS FOR STREAMS WITHOUT ESTABLISHED BASE FLOOD ELEVATIONS AND FLOODWAYS.

   Located within the areas of special flood hazard (Zones A and V) established in § 156.030 are small streams where no base flood data has been provided and where no floodways have been identified. The following provisions apply within such areas:

   (A)   In all areas of special flood hazard where base flood elevation data are not available, the applicant shall provide a hydrologic and hydraulic engineering analysis that generates base flood elevations for all subdivision proposals and other proposed developments containing at least 50 lots or five (5) acres, whichever is less;

   (B)   No encroachments, including fill, new construction, substantial improvements and new development, shall be permitted within 100 feet of the stream bank unless certification with supporting technical data by a registered and professional engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.

   (C)   If § 156.067(A) is satisfied and base flood elevation data is available from other sources, all new construction and substantial improvements within such areas shall comply with all applicable flood hazard provisions of §§ 156.065 and 156.066 and shall be elevated or floodproofed in accordance with elevations established in § 156.069(K).

   (D)   Data from preliminary, draft, and final flood insurance studies constitutes best available data. Refer to FEMA Floodplain Management Technical Bulletin 1-98, Use of Flood Insurance Study (FIS) Data as Available Data. If an appeal is pending on the study in accordance with 44 CFR Ch. 1, Part 67.5 and 67.6, the data does not have to be used.

   (E)   When BFE data is not available from a federal, state, or other source, one (1) of the following methods may be used to determine a BFE. For further information regarding the methods for determining BFEs listed below, refer to FEMA’s manual, Managing Floodplain Development in Approximate Zone A Areas:

      (1)   Contour interpolation.

         (a)   Superimpose approximate Zone A boundaries onto a topographic map and estimate a BFE; or

         (b)   Add one-half (1/2) of the contour interval of the topographic map that is used to the BFE.

      (2)   Data extrapolation. A BFE can be determined if a site within 500 feet upstream of a reach of a stream reach for which a 100-year profile has been computed by detailed methods, and the floodplain and channel bottom slope characteristics are relatively similar to the downstream reaches. No hydraulic structures shall be present.

      (3)   Hydrologic and hydraulic calculations. Perform hydrologic and hydraulic calculations to determine BFEs using FEMA- approved methods and software.

(1985 Code, Ch. 15, Art. V) (Am. Ord. --, passed 4-27-2018)

§ 156.068 STANDARDS FOR STREAMS WITH ESTABLISHED BASE FLOOD ELEVATIONS BUT WITHOUT FLOODWAYS.

   Along rivers and streams where base flood elevation (BFE) data is provided but no floodway is identified for a special flood hazard area on the FIRM or in the FIS, no encroachments, including fill, new construction, substantial improvements, or other development, shall be permitted unless a certification with supporting technical data provided by a registered professional engineer is provided demonstrating 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 (1) foot at any point within the community.

(1985 Code, Ch. 15, Art. V) (Am. Ord. --, passed 4-27-2018)

§ 156.069 STANDARDS FOR AREAS OF SHALLOW FLOODING (AO ZONES).

   Located within the areas of special flood hazard established in § 156.030 are areas designated as shallow flooding. The following provisions shall apply within such areas:

   (A)   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 (3) feet above the highest adjacent grade.

   (B)   All new construction and substantial improvements of non-residential structures shall:

      (1)   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 (3) feet above the highest adjacent grade; or

      (2)   Be completely floodproofed 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 § 156.052(K).

   (C)   All structures on slopes must have drainage paths around them to guide water away from the structures.

(1985 Code, Ch. 15, Art. V) (Am. Ord. --, passed 4-27-2018)

VARIANCE PROCEDURES

§ 156.080 ESTABLISHMENT OF APPEAL BOARD.

   The Zoning Board of Appeals, as established by the Town of South Congaree, shall hear and decide requests for variances from the requirements of this chapter.

(Ord. --, passed 4-27-2018)