Unified Development Ordinance, 4th supplement, September 2017

Part 10A: Unified Development Ordinance City of Raleigh, North Carolina 7 – 21 Effective Date: September 01, 2013 Supp. No. 4 Article 7.2. ​​Landscaping and Screening | CHAPTER 7. ​GENERAL DEVELOPMENT STANDARDS Sec. 7.2.6. ​Stormwater Retention Ponds & Detention Basins iv. Provide at least 2 of the following 3 features: a) Pedestrian access trails to the stormwater control facility from the existing and/or proposed pedestrian network associated with the site or development. Trails are not required to meet the minimum specifications for sidewalks or multipurpose trails as described within the City's standard specifications and details and may be constructed of any discernible, leveled, and stable surface material, including but not limited to: brick or masonry, gravel, mulch, wood chips, mowed grass; b) Inclusion of other permanent, pedestrian-oriented features, including but not limited to: seating, dining tables and mounted trash cans, in areas around or proximate to the stormwater control facility; or c) Grading and slopes of 8:1 or shallower which will allow utilization of the facility as an area for recreation when not in use as a detention facility (except on the dam structure and as is necessary to tie the dam back to existing grades); alternatively, a retaining wall may be incorporated into a portion of the facility, provided the design of walls are compatible with the principal building in terms of texture, quality, material and color. 3. Incentives When a permanent stormwater retention pond or detention basin provides amenity features in compliance with the minimum requirements of this UDO, then the following provisions may also apply: a. The permanent stormwater retention pond and detention basin and related facilities, including amenity features, may be placed within required landscaping areas, including but not limited to: street protective yards, transitional protective yards and parking lot landscaping areas, (except in tree conservation areas adjoining thoroughfares, within areas zoned for resource management, tree protection areas and in natural protective yards); and b. When a permanent stormwater retention pond or detention basin is located within a required landscaping area, the portion of land associated with or adjacent to the stormwater control facility is only required to meet 80% of the minimum planting requirements of the required landscaping area. C. Screening Requirements When amenity features are not provided as set forth in Sec. 7.2.6.B. , screening of the stormwater control facility is required as set forth below. 1. All vegetative screening shall be 75% locally-adapted evergreen species. 2. All vegetative material shall be planted so as to attain a screen occupying at least 75% of a vertical plane around the perimeter of the facility to an average mature height of 6 feet above grade. 3. Screening shall be required around the base of the dam structure (as applicable), but not on the dam structure, with those plant materials in immediate proximity to the dam characterized by shallow, non-invasive root systems. 4. Screening shall not be required within required facility inlets or facility outlets or within a maintenance access path provided that such path does not exceed 12 feet in width; in all other instances, at an average mature height of planting, the maximum open horizontal space between vegetative screening materials shall not be more than 2 feet in width. 5. Vegetative material composing the screen shall be selected and installed so as to exhibit variety in texture, color, spread and height by using ornamental or deciduous shade trees in combination with evergreen materials. 6. In some cases, vegetative material may be placed in clusters or groups to add additional visual interest as well as to achieve intermittent levels of vertical height; and 7. In situations where the stormwater control facility utilizes a fence, all vegetative material associated with screening the facility shall be located outside the fence. 8. In situations where a fence and gate are proposed, the fence and gate shall be colored black, forest green, dark brown or similar dark color, unless the fence is constructed of masonry, wood or similar natural material, in which case it may be left to weather naturally.