(A) General standards. In all special flood hazard areas, the following provisions are required:
(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure;
(2) All new construction and substantial improvements below the regulatory flood protection elevation shall be constructed with materials and utility equipment resistant to flood damage;
(3) All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damages;
(4) Electrical, heating, ventilation, plumbing, air conditioning equipment, 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 flooding. These include, but are not limited to, HVAC equipment, water softener units, bath/kitchen fixtures, ductwork, electric/gas meter panels/boxes, utility/cable boxes, appliances (washers, dryers, refrigerators, freezers, and the like), hot water heaters, and electric outlets/switches;
(5) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;
(6) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters;
(7) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding;
(8) Any alteration, repair, reconstruction, or improvements to a structure which is in compliance with the provisions of this section, shall meet the requirements for new construction as contained in this section;
(9) Nothing in this section shall prevent the repair, reconstruction, or replacement of a building or structure existing on or prior to September 18, 2006 and located totally or partially within the floodway, non-encroachment area, or stream setback, provided that the bulk of the building or structure below the regulatory flood protection elevation in the floodway, non-encroachment area, or stream setback is not increased and provided that such repair, reconstruction, or replacement meets all of the other requirements of this chapter;
(10) New solid waste disposal facilities, hazardous waste management facilities, salvage yards, and chemical storage facilities shall not be permitted in special flood hazard areas, except by variance as specified in § 153.303(C). A structure or tank for chemical or fuel storage incidental to an allowed use or to the operation of a water treatment plant or wastewater treatment facility may be located in a special flood hazard area only if the structure or tank is either elevated or floodproofed to at least the regulatory flood protection elevation and certified according to § 153.247(B);
(11) All subdivision proposals and other development proposals shall be consistent with the need to minimize flood damage;
(12) All subdivision proposals and other development proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;
(13) All subdivision proposals and other development proposals shall have adequate drainage provided to reduce exposure to flood hazards; and
(14) All subdivision proposals and other development proposals shall have received all necessary permits from those governmental agencies for which approval is required by federal or state law, including § 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. § 1334.
(B) Specific standards. In all special flood hazard areas where base flood elevation (BFE) data has been provided, as set forth by the provisions of this subchapter, in addition to division (A) above, are required:
(1) Residential construction. New construction or substantial improvement of any residential structure (including manufactured homes) shall have the reference level, including basement, elevated no lower than the regulatory flood protection elevation, as defined in § 153.024;
(2) Nonresidential construction. New construction or substantial improvement of any commercial, industrial, or nonresidential structure shall have the reference level, including basement, elevated no lower than the regulatory flood protection elevation, as defined in § 153.024. Structures located in A, AO, AE, and A1-30 Zones may be floodproofed to the regulatory flood protection elevation in lieu of elevation provided that all areas of the structure below the required elevation are watertight with walls substantially impermeable to the passage of water, using structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A professional state engineer or architect licensed by the state’s Board of Architecture and certified by same shall certify that the standards of this division are satisfied. Such certification shall be provided to the Floodplain Administrator as set forth in § 153.247(B) along with the operational and maintenance plans;
(3) Manufactured homes.
(a) New or replacement manufactured homes shall be elevated so that the reference level of the manufactured home is no lower than the regulatory flood protection elevation.
(b) Manufactured homes shall be securely anchored to an adequately anchored foundation to resist flotation, collapse, and lateral movement in accordance with the state’s Regulations for Manufactured/Mobile Homes, 1995 Edition, and any revision thereto adopted by the Commissioner of Insurance pursuant to G.S. § 143-143.15 or a certified engineered foundation. Additionally, when the elevation would be met by an elevation of the chassis 36 inches or less above the grade at the site, the chassis shall be supported by reinforced piers or engineered foundation. When the elevation of the chassis is above 36 inches in height, an engineering certification is required.
(c) All foundation enclosures or skirting shall be in accordance with § 153.248(B)(4).
(d) An evacuation plan shall be developed for evacuation of all residents of all new, substantially improved or substantially damaged manufactured home parks or subdivisions located within flood prone areas. This plan shall be filed with and approved by the Floodplain Administrator and the Emergency Service Director.
(4) Elevated buildings. Enclosed areas, of new construction or substantially improved structures, which are below the regulatory flood protection elevation:
(a) Shall not be designed or used for human habitation, but shall only be used for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises. Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment (standard exterior door), or entry to the living area (stairway or elevator). The interior portion of such enclosed area shall not be partitioned or finished into separate rooms, except to enclose storage areas;
(b) Shall be constructed entirely of flood resistant materials below the regulatory flood protection elevation;
(c) Shall include, in Zones A, AO, AE, and A1-30, measures to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters. To meet this requirement, the openings shall either be certified by a professional state engineer or architect licensed by the state’s Board of Architecture and certified by same or meet the following minimum design criteria:
1. Provide a minimum of two openings on different sides of each enclosed area subject to flooding;
2. The total net area of all openings shall be at least one square inch for each square foot of enclosed area subject to flooding;
3. If a building has more than one enclosed area, each area shall have openings to allow floodwaters to automatically enter and exit;
4. The bottom of all required openings shall be no higher than one foot above the adjacent grade;
5. Openings may be equipped with screens, louvers, or other opening coverings or devices, provided they permit the automatic flow of floodwaters in both directions; and
6. Foundation enclosures made of flexible skirting are not considered enclosures for regulatory purposes, and, therefore, do not require openings. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires openings as outlined above.
(5) Additions and improvements.
(a) Additions and/or improvements to pre-FIRM structures when the addition and/or improvements in combination with any interior modifications to the existing structure are:
1. Not a substantial improvement, the addition and/or improvements shall be designed to minimize flood damages and shall not be any more nonconforming than the existing structure; or
2. A substantial improvement, both the existing structure and the addition and/or improvements shall comply with the standards for new construction.
(b) Additions to post-FIRM structures with no modifications to the existing structure other than a standard door in the common wall shall require only the addition to comply with the standards for new construction.
(c) Additions and/or improvements to post-FIRM structures when the addition and/or improvements in combination with any interior modifications to the existing structure are:
1. Not a substantial improvement, the addition and/or improvements only shall comply with the standards for new construction; or
2. A substantial improvement, both the existing structure and the addition and/or improvements shall comply with the standards for new construction.
(d) Where a fire wall or independent perimeter load-bearing wall is provided between the addition and the existing building, the addition(s) shall be considered a separate building and only the addition shall comply with the standards for new construction.
(6) Recreational vehicles. Recreation vehicles placed on sites within a special flood hazard area shall either:
(a) Be on-site for fewer than 180 consecutive days and 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 has no permanently attached additions); or
(b) Meet all the requirements for new construction, including anchoring and elevation requirements of § 153.247(B) and division (B)(3) above.
(7) Temporary nonresidential structures. Prior to the issuance of a floodplain development permit, for a temporary structure, applicants shall submit to the Floodplain Administrator a plan for the removal of such structure(s) in the event of a hurricane, flash flood, or other type of flood warning notification. The following information shall be submitted in writing to the Floodplain Administrator for review and written approval:
(a) A specified time period for which the temporary use will be permitted. Time specified should be minimal with total time on-site not to exceed 12 months;
(b) The name, address, and phone number of the individual responsible for the removal of the temporary structure;
(c) The time frame prior to the event at which a structure will be removed (i.e., minimum of 72 hours before landfall of a hurricane or immediately upon flood warning notification);
(d) A copy of the contract or other suitable instrument with a trucking company to ensure the availability of removal equipment when needed; and
(e) Designation, accompanied by documentation, of a location outside the floodplain to which the temporary structure will be moved.
(8) Accessory structure. When accessory structures (sheds, detached garages, and the like) are to be placed within a special flood hazard area, the following criteria shall be met:
(a) Accessory structures shall be used for human habitation (including work, sleeping, living, cooking, or restroom areas);
(b) Accessory structures shall not be temperature-controlled;
(c) Accessory structures shall be designed to have low flood damage potential;
(d) Accessory structures shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters;
(e) Accessory structures shall be firmly anchored in accordance with division (A)(1) above;
(f) All service facilities such as electrical shall be installed in accordance with division (A)(4) above;
(g) Openings to relieve hydrostatic pressure during a flood shall be provided below flood protection elevation in conformance with division (B)(4)(c)1. above; and
(h) An accessory structure with a footprint less than 150 square feet that satisfies the criteria outlined above does not require an elevation or floodproofing certificate. Elevation or floodproofing certifications are required for all other accessory structures in accordance with § 153.247(B).
(C) Standards for floodplains without established base flood elevations. Within the special flood hazard areas established in § 153.246(B), where no base flood elevation (BFE) data has been provided by FEMA, the following provisions, in addition to division (A) above, shall apply.
(1) No encroachments, including fill, new construction, substantial improvements, or new development shall be permitted within a distance of 20 feet each side from top of bank or five times the width of the stream, whichever is greater, unless certification with supporting technical data by a professional state engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
(2) The BFE used in determining the regulatory flood protection elevation shall be determined based on one of the following criteria set in priority order:
(a) If base flood elevation (BFE) data is available from other sources, all new construction and substantial improvements within such areas shall also comply with all applicable provisions of this chapter and shall be elevated or floodproofed in accordance with standards in § 153.247(C)(11) and (C)(12);
(b) All subdivision, manufactured home park, and other development proposals located within special flood hazard areas shall provide base flood elevation (BFE) data if development is greater than five acres or has more than 50 lots or manufactured home sites. Such base flood elevation (BFE) data shall be adopted by reference per § 153.246(B) to be utilized in implementing this section; and/or
(c) When base flood elevation (BFE) data is not available from a federal, state, or other source as outlined above, the reference level shall be elevated above the highest adjacent grade as required in the regulatory flood protection elevation definition.
(E) Standards for riverine floodplains with BFE but without established floodways or non-encroachment areas. Along rivers and streams where BFE data is provided but neither floodway nor non-encroachment areas are identified for a special flood hazard area on the FIRM or in the FIS report, the following requirements shall apply to all development within such areas:
(1) Standards outlined in divisions (A) and (B) above; and
(2) No encroachments, including fill, new construction, substantial improvements, or other development, shall be permitted unless certification with supporting technical data by a professional state 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 foot at any point within the community.
(F) Floodways and non-encroachment areas. Areas designated as floodways or non-encroachment areas are located within the special flood hazard areas established in § 153.246(B). The floodways and non-encroachment areas are extremely hazardous areas due to the velocity of floodwaters that have erosion potential and carry debris and potential projectiles. The following provisions, in addition to standards outlined in divisions (A) and (B) above, shall apply to all development within such areas:
(1) No encroachments, including fill, new construction, substantial improvements, and other developments shall be permitted unless it has been demonstrated that:
(a) The proposed encroachment would not result in any increase in the flood levels during the occurrence of the base flood, based on hydrologic and hydraulic analyses performed in accordance with standard engineering practice and presented to the Administrator prior to issuance of floodplain development permit; or
(b) A Conditional Letter of Map Revision (CLOMR) has been approved by FEMA. A Letter of Map Revision (LOMR) shall also be obtained upon completion of the proposed encroachment.
(2) If division (E)(1), above, is satisfied, all development shall comply with all applicable flood hazard reduction provisions of this section;
(3) No manufactured homes shall be permitted, except replacement manufactured homes in an existing manufactured home park or subdivision, provided the following provisions are met:
(a) The anchoring and the elevation standards of division (B)(3) above; and
(b) The no encroachment standard of division (E)(1), above, are met.
(G) Standards for areas of shallow flooding (Zone AO). Located within the special flood hazard areas established in § 153.246(B) are areas designated as shallow flooding areas. These areas have special flood hazards associated with base flood depths of one to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate. In addition to division (A) above, all new construction and substantial improvements shall meet the following requirements:
(1) The reference level shall be elevated at least as high as the depth number specified on the Flood Insurance Rate Map (FIRM), in feet, plus a freeboard of two feet, above the highest adjacent grade; or at least two feet above the highest adjacent grade plus a freeboard of two feet if no depth number is specified;
(2) Nonresidential structures may, in lieu of elevation, be floodproofed to the same level as required in division (B)(1) above so that the structure, together with attendant utility and sanitary facilities, below that level shall be 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 per § 153.061(F) and division (B)(2) above; and/or
(3) Adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures.
(Ord. passed 10-17-2011)