A. General standards. In all special flood hazard areas, the following provisions are required:
1. All new construction and substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse, and lateral movement of the structure.
2. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage in accordance with the FEMA Technical Bulletin 2, Flood Damage-Resistant Materials Requirements.
3. All new construction and substantial improvements shall be constructed by methods and practices that minimize flood damages.
4. All new electrical, heating, ventilation, air-conditioning, plumbing, duct systems, and other building utility systems, equipment, and service facilities must be located at or above the regulatory flood protection elevation (RFPE) and/or specially designed to prevent water from entering or accumulating within the components and installed to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation. Utility systems, equipment, and service facilities include, but are not limited to, HVAC equipment, water softener units, bath/kitchen plumbing fixtures, ductwork, electric/gas meter panels/boxes, utility/cable boxes, water heaters, fuel tanks, and electric outlets/switches.
a. Replacement part of a substantial improvement must also meet the above provisions.
b. Replacements that are for maintenance and not part of a substantial improvement, may be installed at the original location, provided the addition and/or improvements comply with the standards for new construction consistent with the code and requirements for the original structure.
5. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
6. 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.
7. On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
8. Nothing in this chapter shall prevent the repair, reconstruction, or replacement of a building or structure existing on the effective date of this chapter and located totally or partially within the floodway, nonencroachment area, or stream setback, provided there is no additional encroachment below the regulatory flood protection elevation in the floodway, nonencroachment area, or stream setback, and provided that such repair, reconstruction, or replacement meets all of the other requirements of this chapter.
9. New solid waste disposal facilities and sites, hazardous waste management facilities, salvage yards, and chemical storage facilities shall not be permitted, except by variance as specified in this section. 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 in accordance with the provisions of Sec. 8-1.16.
10. All subdivision proposals and other development proposals shall be consistent with the need to minimize flood damage.
11. 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.
12. All subdivision proposals and other development proposals shall have adequate drainage provided to reduce exposure to flood hazards.
13. 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 Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1334.
14. When a structure is partially located in a special flood hazard area, the entire structure shall meet the requirements for new construction and substantial improvements.
15. When a structure is located in multiple flood hazard zones or in a flood hazard risk zone with multiple base flood elevations, the provisions for the more restrictive flood hazard risk zone and the highest base flood elevation (BFE) shall apply.
16. Buildings and structures that are located in more than one flood hazard area shall comply with the provisions associated with the most restrictive flood hazard area.
1. Residential construction. New construction and 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 Sec. 8-1.20 of this chapter.
2. Non-residential construction. New construction and substantial improvement of any commercial, industrial, or other non-residential structure shall have the reference level, including basement, elevated no lower than the regulatory flood protection elevation, as defined in Sec. 8-1.20 of this chapter. Structures located in A, 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, together with attendant utility and sanitary facilities, below the regulatory flood protection 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 registered professional engineer or architect shall certify that the floodproofing standards of this subsection are satisfied. Such certification shall be provided to the Floodplain Administrator as set forth in Sec. 8-1.16, along with the operational plan and the inspection and maintenance plan.
3. Manufactured homes.
a. New and replacement manufactured homes shall be elevated so that the reference level of the manufactured home is no lower than the regulatory flood protection elevation, as defined in Sec. 8-1.20 of this article.
b. Manufactured homes shall be securely anchored to an adequately anchored foundation to resist flotation, collapse, and lateral movement, either by certified engineered foundation system, or in accordance with the most current edition of the State of North Carolina Regulations for Manufactured Homes adopted by the Commissioner of Insurance pursuant to G.S. 143-143.15. Additionally, when the elevation would be met by an elevation of the chassis thirty-six (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 thirty-six (36) inches in height, an engineering certification is required.
c. All enclosures or skirting below the lowest floor shall meet the requirements of Sec. 8-1.19.B.4.
d. An evacuation plan must 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 local Emergency Management Coordinator.
4. Elevated buildings. Fully enclosed area, of new construction and substantially improved structures, which is below the lowest floor:
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 finished or partitioned into separate rooms, except to enclose storage areas;
b. Shall be constructed entirely of flood resistant materials at least to the regulatory flood protection elevation; and
c. Shall include flood openings to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters. To meet this requirement, the openings must either be certified by a professional engineer or architect or meet or exceed the following minimum design criteria:
i. A minimum of two (2) flood openings on different sides of each enclosed area subject to flooding;
ii. The total net area of all flood openings must be at least one (1) square inch for each square foot of enclosed area subject to flooding;
iii. If a building has more than one (1) enclosed area, each enclosed area must have flood openings to allow floodwaters to automatically enter and exit;
iv. The bottom of all required flood openings shall be no higher than one (1) foot above the adjacent grade;
v. Flood openings may be equipped with screens, louvers, or other coverings or devices, provided they permit the automatic flow of floodwaters in both directions; and
vi. Enclosures made of flexible skirting are not considered enclosures for regulatory purposes, and, therefore, do not require flood openings. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires flood openings as outlined above.
5. Additions/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:
i. Not a substantial improvement, the addition and/or improvements must be designed to minimize flood damages and must not be any more nonconforming than the existing structure.
ii. A substantial improvement, both the existing structure and the addition and/or improvements must 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:
i. Not a substantial improvement, the addition and/or improvements only must comply with the standards for new construction.
ii. A substantial improvement, both the existing structure and the addition and/or improvements must comply with the standards for new construction.
d. Any combination of repair, reconstruction, rehabilitation, addition or improvement of a building or structure taking place during a one (1) year period, the cumulative cost of which equals or exceeds fifty (50) percent of the market value of the structure before the improvement or repair is started, must comply with the standards for new construction. For each building or structure, the one (1) year period begins on the date of the first improvement or repair of that building or structure subsequent to the effective date of this chapter. Substantial damage also means flood-related damage sustained by a structure on two (2) separate occasions during a ten (10)-year period, for which the cost of repairs at the time of each such flood event, on the average, equals or exceeds twenty-five (25) percent of the market value of the structure before the damage occurred. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The requirement does not, however, include either:
i. Any project for improvement of a building required to correct existing health, sanitary, or safety code violations identified by the Building Official and that are the minimum necessary to assume safe living conditions.
ii. Any alteration of a historic structure provided that the alteration will not preclude the structure's continued designation as a historic structure.
6. Recreational vehicles.
a. Temporary placement.
i. Be on site for fewer than one hundred eighty (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
ii. Meet all the requirements for new construction.
b. No more than two (2) forty (40)-pound LP tanks shall be permitted per recreational vehicle located within a SHFA designated as "floodway"; campgrounds and other approved sites that provide fuel service to recreational vehicles shall properly install and anchor all LP tanks in accordance with Sec. 8-1.19.B.9 Tanks, and with the National Fire Protection Association Chapter 58 (NFPA 58) Liquefied Petroleum Gas Code, Ed. 2011 as may be amended.
7. Temporary non-residential structures. Prior to the issuance of a floodplain development permit for a temporary structure, the applicant must 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 may not exceed three (3) months, renewable up to one (1) year;
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 seventy-two (72) hours before landfall of a hurricane or immediately upon flood warning notification);
d. A copy of the contract or other suitable instrument with the entity responsible for physical removal of the structure; and
e. Designation, accompanied by documentation, of a location outside the special flood hazard area, to which the temporary structure will be moved.
8. Accessory structures. When accessory structures (sheds, detached garages, etc.) are to be placed within a special flood hazard area, the following criteria shall be met:
a. Accessory structures shall not be used for human habitation (including working, 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 the provisions of Sec. 8-1.19.A.1;
f. All service facilities such as electrical shall be installed in accordance with the provisions of Sec. 8-1.19.A.4;
g. Flood openings to facilitate automatic equalization of hydrostatic flood forces shall be provided below regulatory flood protection elevation in conformance with the provisions of subsection 8-1.19.B.4. c; and
h. An accessory structure with a footprint less than one hundred fifty (150) square feet that satisfies the criteria outlined above does not require an elevation or floodproofing certificate. Elevation or flood-proofing certifications are required for all other accessory structures in accordance with subsection 8-1.19.B.4.
9. Tanks. When gas and liquid storage tanks are to be placed within a special flood hazard area, the following criteria shall be met:
a. Underground tanks. Underground tanks in flood hazard areas shall be anchored to prevent flotation, collapse or lateral movement resulting from hydrodynamic and hydrostatic loads during conditions of the design flood, including the effects of buoyancy, assuming the tank is empty;
b. Above-ground tanks, elevated. Above-ground tanks in flood hazard areas shall be elevated to or above the regulatory flood protection elevation on a supporting structure that is designed to prevent flotation, collapse or lateral movement during conditions of the design flood. Tank-supporting structures shall meet the foundation requirements of the applicable flood hazard area;
c. Above-ground tanks, not elevated. Above-ground tanks that do not meet the elevation requirements of Section 8-1.19.B.2 of this chapter shall be permitted in flood hazard areas provided the tanks are designed, constructed, installed, and anchored to resist all flood-related and other loads, including the effects of buoyancy, during conditions of the design flood and without release of contents in the floodwaters or infiltration by floodwaters into the tanks. Tanks shall be designed, constructed, installed, and anchored to resist the potential buoyant and other flood forces acting on an empty tank during design flood conditions.
d. Tank inlets and vents. Tank inlets, fill openings, outlets, and vents shall be:
i. At or above the regulatory flood protection elevation or fitted with covers designed to prevent the inflow of floodwater or outflow of the contents of the tanks during conditions of the design flood; and
ii. Anchored to prevent lateral movement resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, during conditions of the design flood.
10. Other development.
a. Fences in regulated floodways and NEAs that have the potential to block the passage of floodwaters, such as stockade fences and wire mesh fences, shall meet the limitations of this chapter.
b. Retaining walls, sidewalks and driveways in regulated floodways and NEAs. Retaining walls, sidewalks, and driveways that involve the placement of fill in regulated floodways shall meet the limitations of this chapter.
c. Roads and watercourse crossings in regulated floodways and NEAs. Roads and watercourse crossings, including roads, bridges, culverts, low-water crossings and similar means for vehicles or pedestrians to travel from one (1) side of a watercourse to the other side, that encroach into regulated floodways shall meet the limitations of this chapter.
d. Commercial storage facilities are not considered "limited storage" as noted in this chapter, and shall be protected to the regulatory flood protection elevation as required for commercial structures.
C. Standards for floodplains without established base flood elevations.
2. No encroachments, including fill, new construction, substantial improvements or new development shall be permitted within a distance of twenty (20) feet each side from the top of the bank or five (5) times the width of the stream, whichever is greater, unless certification with supporting technical data by a registered 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.
3. The BFE used in determining the regulatory flood protection elevation shall be determined based on the following criteria:
a. When base flood elevation (BFE) data are 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 the general and specific standards in Sec. 8-1.19.
b. When floodway or non-encroachment data are available from a federal, state, or other source, all new construction and substantial improvements within floodway and non-encroachment areas shall also comply with the requirements of Sec. 8-1.19.B and E.
c. All subdivision, manufactured home park and other development proposals shall provide base flood elevation (BFE) data if development is greater than five (5) acres or has more than fifty (50) lots/manufactured home sites. Such BFE data shall be adopted by reference in accordance with the provisions of this article and utilized in implementing this chapter.
d. When base flood elevation (BFE) data are not available from a federal, state, or other source as outlined above, the reference level shall be elevated or floodproofed (nonresidential) to or above the regulatory flood protection elevation, as defined in Sec. 8-1.20. All other applicable provisions of Sec. 8-1.19.B. shall also apply.
D. Standards for riverine floodplains with BFE but without established floodways or non-encroachment areas. Along rivers and streams where base flood elevation (BFE) data is provided by FEMA or is available from another source, 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 of Sec. 8-1.19 subsections B and C; and
2. Until a regulatory floodway or non-encroachment area is designated, no encroachments, including fill, new construction, substantial improvements, or other development, shall be permitted unless certification with supporting technical data 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.
E. Standards floodways and non-encroachment areas. Areas designated as floodways or non-encroachment areas are located within the special flood hazard areas established in Sec. 8-1.8. 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 the standards outlined in Sec. 8-1.19 subsections B and C, shall apply to all development within such areas:
1. No encroachments, including fill, new construction, substantial improvements and other developments shall be permitted unless:
a. It is demonstrated that 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 Floodplain 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) must also be obtained upon completion of the proposed encroachment.
2. If subsection E.1 is satisfied, all development shall comply with all applicable flood hazard reduction provisions of this chapter.
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:
i. The anchoring and the elevation standards of subsection 8-1.19.E.3; and
ii. The no encroachment standard of subsection 8-1.19.E.1.
(Ord. No. O-23-04-18-3, § 1, 4-18-23)