Unified Development Ordinance, 25th Supplement, December 2022

CHAPTER 9. ​NATURAL RESOURCE PROTECTION | Article 9.3. ​Floodprone Area Regulations

B. Specific SFHA Standards Work permitted within all SFHAs shall meet the following specific standards: 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 RFPE and meet the provisions of Sec. 11.4.6 and this Article. 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 RFPE. Structures may be floodproofed to the RFPE in lieu of elevation provided that all areas of the structure, together with attendant utility and sanitary facilities, below the RFPE 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 licensed in the State of North Carolina shall certify that the floodproofing standards of this Article and provisions of Sec. 11.4.6. are satisfied. 3. Manufactured Homes a. All new and replacement manufactured homes placed within a SFHA shall be elevated so that the reference level of the manufactured home is no lower than the RFPE. b. All new and replacement manufactured homes placed within a SFHA 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 N.C. Gen. Stat. § 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)

totally or partially within the floodway, non-encroachment area, or stream setback, provided there is no additional encroachment below the RFPE in the floodway, non-encroachment area, or stream setback, and provided that such repair, reconstruction, or replacement meets all of the other requirements of this Article and Article 11.4. 9. No chemical storage facilities which store or process acetone, acetylene gas, ammonia, benzene, calcium carbide, carbon disulfide, celluloid, chlorine, gasoline, hydrochloric acid, hydrocyanic acid, magnesium, materials or fuel which are flammable or explosive, nitric acid, oxides of nitrogen, petroleum products, phosphorus, potassium, sodium, sulfur, or any other items which in time of flooding are buoyant or could be injurious to human, animal, or plant life are allowed in any SFHA. 10. No new solid waste disposal facilities, hazardous waste management facilities, and salvage yards are allowed in any SFHA. 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. 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, but not limited to, Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1334. 15. For new construction and substantial improvements, when a structure is partially located within a SFHA, the entire structure shall meet the SFHA standards for new construction and substantial improvements. 16. For new construction and substantial improvements, when a structure is in a flood hazard risk zone with multiple BFEs, the standards for the more restrictive flood hazard risk zone and the highest BFE shall apply. 17. For new construction and substantial improvements, buildings and structures that are in more than one SFHA shall comply with the standards associated with the most restrictive SFHA.

Supp. No. 25

9 – 32 Pub l i s hed De c embe r 2022

Pa r t 10 : Un i f i ed Deve l opmen t Or d i nanc e C i t y o f Ra l e i gh , No r t h Ca r o l i na