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Article 6: Development Standards 33 <br /> Section 6.14: Stormwater Management <br /> (1) The stormwater run-off generated by one inch of rain from all project area <br /> surfaces shall be controlled to the extent possible through on-site infiltration and <br /> through the use of methods which rely on natural soil properties for absorption <br /> and treatment. <br /> (2) Run-off from roads, parking lots, and/or sidewalks shall be directed to <br /> undisturbed areas through use of berms, grassed diversion ditches or swales, or <br /> other acceptable means to reduce run-off velocity and filter out pollutants. <br /> (3) Impervious Surface Limits <br /> (a) In order to promote infiltration of stormwater runoff into the soil and <br /> minimize direct and immediate runoff into streams and water supply <br /> impoundments, the maximum percentage of the total lot area which may <br /> be covered with an impervious surface shall be specified. This limit is <br /> referred to as the "impervious surface ratio". <br /> (b) Impervious surface calculations for an individual development shall be <br /> cumulative for original construction and any subsequent additions. One- <br /> half of the width of any of any existing or proposed road adjacent to an <br /> individual lot shall be included as impervious surface for that lot, except <br /> in the case where an existing road was contained within a dedicated <br /> public right-of-way at the time that the watershed regulations were first <br /> applied to the watershed within which the development is located. <br /> (4) Infiltration Techniques <br /> (a) The benefits of infiltration techniques include: <br /> (i) Removal of both suspended and dissolved pollutants, <br /> (ii) They require less maintenance, <br /> (iii) They reduce flooding, <br /> (iv) They promote groundwater recharge, and <br /> (v) They help maintain stream flow during dry periods. <br /> (b) Where on-site infiltration methods are utilized, areas for such purposes <br /> shall be designated on the plat and shall remain undisturbed both during <br /> and after construction. <br /> (c) Undisturbed areas for infiltration of run-off shall also be located <br /> downslope from impervious surfaces and shall not include areas <br /> characterized by floodplains, highly erodible or impervious soils, steep <br /> slopes or previously disturbed areas. <br /> (d) Areas designated as suitable for septic tank nitrification fields may not be <br /> used for stormwater infiltration purposes. <br /> (B) StruGtural Stermwater 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 rmwater <br /> measuresSCMS, which capture stormwater for slow release through an outlet, <br /> are required. <br /> (2) Where required, GtFU tWal stem;wator m esSCMs 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 />