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Article 6: Development Standards37 <br /> Section 6.14: Stormwater Management <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 Systems <br /> (a) The benefits of Infiltration Systems include, but are not limited to: <br /> (i) Removal of both suspended and dissolved pollutants, <br /> (ii) Relatively low maintenance requirements, <br /> (iii) Flood reduction, <br /> (iv) Promotion of groundwater recharge, and <br /> (v) Maintenance of stream flow during dry periods. <br /> (b) Where on-site Infiltration Systems 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 designated for infiltration of stormwater runoff shall <br /> also be located downslope from impervious surfaces and shall not <br /> include areas characterized by floodplains, highly erodible or impervious <br /> soils, steep slopes or previously disturbed areas. <br /> (d) Areas designated as suitable for septic tank nitrification fields may not be <br /> used for stormwater runoff infiltration purposes. <br /> (B) Stormwater Control Measures (SCMs) <br /> (1) In cases where non-structural methods may not adequately control the <br /> stormwater runoff generated by the first inch of rain from all project surfaces due <br /> to the amount of impervious surface proposed to be developed, or in cases <br /> where Non-Structural Methods are not effective or appropriate due to factors <br /> such as the presence of highly erodible soils, impervious soils, steep slopes, <br /> and/or lack of vegetative cover, permanent Stormwater Control Measures <br /> (SCMs), which capture stormwater runoff for slow release through a controlled <br /> outlet, are required. <br /> (2) Where required, SCMs shall be constructed in accordance with this Section. <br /> (C) Impervious Surface and SCM Requirements <br /> (1) For all protected watersheds, an absolute limit on the percentage of lot area <br /> which can be covered with impervious surfaces has been established. See <br /> Section(s)4.2.5 and 4.2.6 of this Ordinance. <br /> (2) In some cases, SCMs are required when the proposed impervious surface ratio <br /> exceeds a specified percentage, which is below the absolute limit. <br /> 6.14.5 Applicability <br /> (A) The stormwater management standards and regulations included herein are applicable to <br /> all new development within the Orange County planning jurisdiction, including private, <br /> public, state, and federal development not covered by a separate NPDES permit, as <br /> follows: <br /> (1) Falls Lake Watershed <br /> Orange County, North Carolina—Unified Development Ordinance Page 6-97 <br />