Morrisville Unified Development Ordinance - June 2017

Article 6: Riparian Buffers Section 6.8. Uses and Activities Permitted in Riparian Buffers 6.6.3. Riparian Buffer Variance Review Standards

Table 6.8: Uses and Activities Permitted in Riparian Buffers

Allowable with Mitigation [3]

Use or Activity

Exempt [1] Allowable [2]

New drainage ditches, roadside ditches and stormwater conveyances applicable to linear projects that do not provide a stormwater management facility due to topography constraints provided that other practicable BMPs are employed [9] Existing drainage ditches, roadside ditches, and stormwater outfalls provided that they are managed to minimize the sediment, nutrients and other pollution that convey to waterbodies [8] New drainage ditches, roadside ditches and stormwater outfalls provided that a stormwater management facility is installed to control nitrogen and attenuate flow before the conveyance discharges through the riparian buffer [8] New drainage ditches, roadside ditches and stormwater outfalls that do not provide control for nitrogen before discharging through the riparian buffer [8] Excavation of the streambed in order to bring it to the same elevation as the invert of a ditch [8] Drainage of a pond in a natural drainage way provided that a new riparian buffer that meets the requirements of this article is established adjacent to the new channel Driveway crossings of streams and other surface waters subject to this article: Driveway crossings on single family residential lots that disturb no more than 25 linear feet or 2,500 square feet of riparian buffer Driveway crossings on single family residential lots that disturb more than 25 linear feet or 2,500 square feet of riparian buffer Driveway crossings in a subdivision that cumulatively disturb no more than 150 linear feet or 1/3 acre of riparian buffer Driveway crossing in a subdivision that cumulatively disturb more than 150 linear feet or 1/3 of an acre of riparian buffer Driveway impacts other than crossing of a stream or other surface waters subject to this article [9] Fences where disturbance is minimized and installation does not result in removal of trees as defined in this Ordinance Fences where disturbance is minimized and installation results in removal of trees as defined in this Ordinance [9] Fertilizer application: one-time application to establish vegetation Grading and revegetation in Zone Two where diffuse flow and the health of existing vegetation in Zone One is not compromised and disturbed areas are stabilized until they are revegetated Grading and revegetation in Zone Two where diffuse flow and the health of existing vegetation in Zone One is not compromised and disturbed areas are stabilized [8] Greenway/hiking trails designed, constructed, and maintained to maximize nutrient removal and erosion protection, minimize adverse effects on aquatic life and habitat, and protect water quality to the maximum extent practical [9] Maintenance access on modified natural streams via a grassed travel way on one side of the water body where less impacting alternatives are not practical, the width and specifications of the travel way are only that needed for equipment access and operation, and the travel way is located to maximize stream shading [9] Greenway/hiking trails [8] Historic preservation

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Morrisville, NC

June 23, 2017

Unified Development Ordinance

Page 6-13