Orange County NC Website
Browse       Search
Article 6: Development Standar" <br /> Section 6.14: Stormwater Management <br /> (1) The stormwater run-off generated by one inch of rain from all project ar a <br /> surfaces shall be controlled to the extent possible through on-site infi ation and <br /> through the use of methods which rely on natural soil properties for bsorption <br /> and treatment. <br /> (2) Run-off from roads, parking lots, and/or sidewalks shall be dir ted to <br /> ndisturbed areas through use of berms, grassed diversion tches or swales, or <br /> of er acceptable means to reduce run-off velocity and filte out pollutants. <br /> (3) Impe vious Surface Limits <br /> (a) order to promote infiltration of stormwater unoff into the soil and <br /> m imize direct and immediate runoff into reams and water supply <br /> imp ndments, the maximum percenta of the total lot area which may <br /> be co red with an impervious surfac shall be specified. This limit is <br /> referred as the "impervious surfa ratio". <br /> (b) Impervious urface calculations f an individual development shall be <br /> cumulative fo original construc ion and any subsequent additions. One- <br /> half of the width f any of any xisting or proposed road adjacent to an <br /> individual lot shal a includ d as impervious surface for that lot, except <br /> in the case where a exis ng road was contained within a dedicated <br /> public right-of-way at time that the watershed regulations were first <br /> applied to the waters within which the development is located. <br /> (4) Infiltration Techniques <br /> (a) The benefits of' filtration tech 'ques include: <br /> (i) Re val of both suspen d and dissolved pollutants, <br /> (ii) T ey require less maintenan e, <br /> (iii) They reduce flooding, <br /> (iv) They promote groundwater rechar , and <br /> They help maintain stream flow durin ry periods. <br /> (b) Where on-site infiltration methods are utilized, ar s for such purposes <br /> shall be designated on the plat and shall remain un 'sturbed both during <br /> and after construction. <br /> (c) Undisturbed areas for infiltration of run-off shall also be I ated <br /> downslope from impervious surfaces and shall not include eas <br /> characterized by floodplains, highly erodible or impervious so's, steep <br /> slopes or previously disturbed areas. <br /> (d) Areas designated as suitable for septic tank nitrification fields may of be <br /> used for stormwater infiltration purposes. <br /> (B) Structural Stormwater MeasuresStormwater Control Measures (SCMs) <br /> (1) In cases where non-structural methods may not adequately control the runoff <br /> from the first inch of rain due to the amount of impervious surface proposed to be <br /> developed, and other factors such as soil type, slope, presence of floodplains <br /> and erodible soils, and/or lack of vegetative cover, StFU .tUral st rW,water <br /> ,;,easuresSCMS, which capture stormwater for slow release through an outlet, <br /> are required. <br /> (2) Where required, StFWGt„ral ster,,.,water moan,�resSCMs shall be constructed in <br /> accordance with this Section. <br /> (C) Impervious Surface and Detention Pond Requirements <br /> Orange County, North Carolina—Unified Development Ordinance Page 6-96 <br />