Unified Development Ordinance, 31st Supplement, May 2024

CHAPTER 9. ​NATURAL RESOURCE PROTECTION | Article 9.5. Watershed Protection Areas

e. Enon fine sandy loam, 10% to 15% slopes (EnD2); f. Georgeville silt loam, 10% to 15% slopes (GeD2); g. Granville sandy loam, 10% to 15% slopes (GrD); h. Helena sandy loam, 10% to 15% slopes (HeD); i. Herndon silt loam, 10% to 25% slopes (HrD2); j. Herndon silt loam, 15% to 25% slopes (HrE); k. Lloyd loam, 10% to 15% slopes (LdD2); l. Louisburg loamy sand, 10% to 15% slopes (LoD); m. Made land, (Ma) greater than 4% slopes under actual field conditions;

6. Exception Where piped, paved or armored storm drainage facilities connect to existing off-site piped, paved or armored storm drainage facilities or where it can be demonstrated that stormwater discharge velocities will not create an erosion problem in the receiving watercourse, none of the foregoing provisions of this section shall apply. 7. Equivalent Alternatives The management of stormwater runoff to minimize or control downstream channel and bank erosion is a developing technology. Innovative techniques and ideas will be considered and may be used when shown to have the potential to produce successful results. Alternatives include, but are not limited to: a. Avoid increases in surface runoff volume and velocity by including measures to promote infiltration to compensate for increased runoff from areas rendered impervious; b. Avoid increases in stormwater discharge velocities by using vegetated or roughened swales and waterways in lieu of closed drains and high velocity paved sections; c. Provide energy dissipators at outlets of storm drainage facilities to reduce flow velocities to the discharge point. These may range from simple rip-rapped sections to complex structures; and d. Protect watercourses subject to accelerated erosion by improving cross sections or providing erosion-resistant lining. H. Operations in Lakes or Natural Watercourses 1. Any land-disturbing activity in connection with construction in, on, over or under a lake or natural watercourse shall be planned and conducted in such a manner so as to minimize the extent and duration of disturbance of the stream channel and to prevent off-site sedimentation. 2. The relocation of a natural watercourse must meet the provisions of Sec. 9.4.4.G. and must minimize changes to the stream flow characteristics. The relocation of a natural watercourse may not occur in natural resource buffer yards of a -UWPOD, -FWPOD, -SWPOD, -MPOD or CM District.

n. Madison sandy loam, 10% to 15% slopes (MdD2); o. Madison sandy loam, 15% to 25% slopes (MdE2); p. Mayodon sandy loam, 10% to 15% slopes (MfD2); q. Mayodan sandy loam, 15% to 25% slopes (MfE); r. Mayodan silt loam, 10% to 15% slopes (MyD); s. Pinkston sandy loam, 10% to 45% slopes (PkF); t. Wake, 10% to 25% slopes (WkE); u. Wedowee sandy loam, 10% to 15% slopes (WmD2); v. Wedowee sandy loam, 15% to 25% slopes (WmE); w. White Store sandy loam, 10% to 20% slopes (WsE); x. White Store clay loam, 2 to 15% slopes (WvD3); y. Wilkes, 10% to 20% slopes (WwE); z. Wilkes, 20% to 45% slopes (WwF); and aa. Wilkes, 15% to 25% slopes (WxE). 5. Armored

Armored or otherwise non-vegetatively lined watercourse lining shall, in addition to the requirements of Sec. 9.4.4.G.3. above, be provided at the storm outlet and for those portions of the receiving watercourse which have undergone land-disturbing activity.

9 – 49 Published May 2024

Part 10: Unified Development Ordinance City of Raleigh, North Carolina

Supp. No. 31