Unified Development Ordinance, 4th supplement, September 2017

Part 10A: Unified Development Ordinance City of Raleigh, North Carolina 9 – 21 Effective Date: September 01, 2013 Supp. No. 4 iii. Land-disturbing activity on slopes greater than 20%may occur no closer than 95 feet to the edge of a watercourse. iv. Upon a recommendation of the Stormwater Management Advisory Commission and approval by the City Council, land-disturbing activities may exceed the standards above; provided that the person submitting the request shows that the potential for stormwater infiltration within a site, the control of stormwater velocity and the restriction of sedimentation both during and after construction are equal to or greater than that which would have been achieved following standards in this Article. The applicant must also show that maintenance provisions are made to maintain the level of infiltration, velocity control and sedimentation on the site. 2. Property located within a riparian water surface buffer and within a required natural resource buffer, must also comply withTitle 15A of the North Carolina Administrative Code Subarticle 2B, section .0233, as amended from time to time. 3. Property located inside of a riparian water surface buffer and outside a required natural resource buffer is subject toTitle 15A of the North Carolina Administrative Code Subarticle 2B, section .0233, as amended from time to time. C. Regulations Applied to Uses Allowed in Watercourse Buffers 1. Regulations Applying to All Natural Resource Buffers Persons who install utility mains shall submit a plan to the City proving that sediment loss during and after installation is less than would have been achieved if other locations outside the buffer were used. 2. Regulations Applying to Both Primary and Secondary Buffer Areas a. Stormwater Control Facilities in Primary or Secondary Areas Stormwater control facilities may be allowed within a primary or secondary area only if the following requirements are met: i. The constructed uses within the buffer area require the use of such facilities; ii. The provisions of Sec. 9.4.4.G.4. require facilities in the buffer area; iii. A wet pond is required by Sec. 9.5.1. , Sec. 9.5.2. o r Sec. 9.5.3. ; or iv. A lake or wet pond is created or preserved. b. Stormwater Control Facilities in Required Buffers Stormwater control facilities may be allowed within required buffer areas only if the following requirements are met. i. The velocity of the stormwater shall not exceed a non-erodible velocity, according to Sec. 9.4.4.G.3. , beyond the outlet of the storm control facilities. ii. Trees over 2-inch DBH which: a) Would be destroyed by installation of storm control facilities, but not including lakes or wet ponds; b) Lie within the greater distance of either a 7-foot radius or 1 foot in diameter for each inch of circumference of the tree measured from the outer edge of the grading limits of a storm drainage project shall be replaced by 1 new tree planted in the same general location, all to achieve the same effect as shown on an approved site plan. The planting must be a minimum caliper of 2 inches and be at least 8 feet tall at time of planting; and c) This provision shall not require trees to be planted on cleared land forming the basin of a wet pond or lake. iii. Stormwater control facilities, which are permitted in the primary and secondary buffer area, shall comply with Sec. 9.5.1.C. , Sec. 9.5.2.C. or Sec. 9.5.3.C. D. Diffuse Stormwater Flow Required 1. All stormwater runoff from new man-made stormwater control facilities, including new ditches or canals, which flow into a watercourse natural resource buffer or into riparian surface water buffer shall be diffused flow so as not to concentrate stormwater or form gullies. 2. Diffuse flow shall be maintained. 3. The landowner or person in possession or control of the land shall be responsible for dispersing concentrated flow of stormwater runoff. 4. The landowner shall take corrective action to prevent the formation of erosion gullies and the landowner shall take corrective action to restore diffuse flow. Article 9.2. Stormwater Management | CHAPTER 9. ​NATURAL RESOURCE PROTECTION Sec. 9.2.3. Watercourse Buffers