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Article 6: Development StandgrM <br /> Section 6.15:Soil Erosion and Sedimentation Control268F <br /> After development of a site, the peak discharge of stormwater runoff resulting from a <br /> 10t€rx327-year storm shall be no greater than that which would result from a 10tan328-year <br /> storm on the same site prior to development. This requirement shall apply to the <br /> following: <br /> (1) Commercial, industrial, office, and institutional developments, <br /> (2) Multi-family residential developments of more than ten units, and <br /> (3) Single-family detached residential developments where more than three lots are <br /> to be created. <br /> (B) Control of Velocity <br /> (1) Persons shall plan and conduct ' ' Land-Disturbing Activity so <br /> that the post-construction velocity of the 10-year stormwater runoff in the <br /> receiving watercourse to the discharge point does not exceed the greater of: <br /> (a) The velocity established by the table in Section 6.15.8(C)(3)of the <br /> subsection; or <br /> (b) The velocity of the 10-year stormwater runoff in the receiving <br /> watercourse prior to development. <br /> (2) If conditions (a) or(b) of this Subsection above cannot be met,then the receiving <br /> watercourse, to and including the discharge point, shall be designed and <br /> constructed to withstand the expected velocity anywhere the velocity exceeds the <br /> "prior to development' velocity by 10%. <br /> (C) Standards <br /> (1) Intent <br /> Stream banks and channels downstream from any land--disturbing activity shall <br /> be protected from increased degradation by accelerated erosion caused by <br /> increased velocity of stormwater runoff from the land---disturbing activity. <br /> (2) Acceptable Management Measures <br /> (a) Measures applied alone or in combination to satisfy the intent of this <br /> Subsection are acceptable if there are no objectionable secondary <br /> consequences. <br /> (b) Innovative techniques and ideas will be considered and may be used <br /> when shown to have the potential to produce successful results. Some <br /> alternatives are to: <br /> (i) Avoid increases in s--dare-stormwater runoff volume and velocity <br /> by including measures to promote Infiltration to compensate for <br /> increased stormwater runoff from areas rendered impervious; <br /> (ii) Avoid increases in stormwater dfssharge runoff velocities by <br /> using vegetated or roughened swales and waterways in lieu of <br /> closed drains and high velocity paved sections; <br /> (iii) Provide energy dissipaters at outlets of storm drainage facilities <br /> to reduce #ow-stormwater runoff velocities to the point of <br /> discharge; these may range from simple rip-rapped sections to <br /> complex structures; and <br /> (iv) Protect watercourses subject to accelerated erosion by <br /> improving cross sections and/or providing erosion-resistant <br /> lining. <br /> 117 Text correction—consistent use of"10-year"within this sub-section. <br /> azs Text correction—consistent use of"10-year"within this sub-section. <br /> Orange County, North Carolina— Unified Development Ordinance Page 6-134 <br />