Unified Development Ordinance, 25th Supplement, December 2022

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

2. Drainage Basin Study Maps

2. To minimize expenditure of public money for costly flood control projects; 3. To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public; 4. To minimize prolonged business losses and interruptions; 5. To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets, and bridges located in SFHAs; 6. To minimize damage to private and public property due to flooding; 7. To make flood insurance available to the community through the National Flood Insurance Program (NFIP); 8. To maintain the natural and beneficial functions of SFHAs; 9. To help maintain a stable tax base by providing for the sound use and development of SFHAs; and, 10. To insure that potential home buyers are aware that property is in a SFHA. Sec. 9.3.2. Applicability A. A flood permit to develop in any regulated SFHA shall be required in conformance with the provisions of this Article and Sec. 11.4.1. prior to commencement of any development within a SFHA. B. Unless otherwise exempt from compliance pursuant to Sec. 9.3.6. or Sec. 9.3.7., no structure or land shall hereafter be located, extended, converted, or structurally altered without full compliance with the terms of this Article and

3. Flood Hazard Soils

A City accepted detailed boundary study shall supersede the boundaries of the flood hazard soils if the boundaries conflict.

B. Establishing Special Flood Hazard Areas 1. FEMA Designated SFHA

a. FEMA designated SFHAs are those identified under the Cooperating Technical State (CTS) agreement between the State of North Carolina and FEMA in its flood insurance study (FIS) and its accompanying FIRM forWake County or DurhamCounty, whichever is applicable. b. The most recent FEMA SFHA maps and FIRMs officially adopted by the State of North Carolina and/or FEMA, with accompanying supporting data, including Letters of Map Amendment or Revision, are adopted by reference and declared to be a part of the UDO. Copies of the effective versions of these maps shall be maintained for public inspection as provided in N.C. Gen. Stat. § 160D-105. c. FEMA SFHAs are areas that have the potential to be inundated with flood waters during the 100-year storm event or the 1% annual chance. These SFHAs include contributing drainage areas of at least 1 square mile (640 acres). d. FEMA designated SFHAs are divided into three (3) primary areas: i. Floodway areas; ii. Floodway fringe areas; and iii. Future conditions flood hazard areas. 2. SFHA Based on Drainage Basin Study Maps a. SFHAs also include City prepared drainage basin studies. These studies are defined through standard engineering analysis by the City’s Engineering Services Department, but which have not been incorporated in the FIRM. This includes detailed flood information generated as a requirement of Sec. 9.3.3.B.1.a.

other applicable federal, state, and local regulations. Sec. 9.3.3. Special Flood Hazard Areas A. Types of Special Flood Hazard Areas There are three (3) primary SFHAs within the City. 1. FEMA designated SFHA

If FEMA designated SFHA boundaries overlap with the boundaries of another SFHA, FEMA designated SFHA boundary interpretations and standards shall prevail.

Supp. No. 25

9 – 28 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