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conditions on site. If better conditions exist, the velocities will be allowed to increase <br />• without lining. If worse conditions exist, lining may be needed for lower velocities. <br />(b) Freeboard will be a minimum of 0.3 feet. Protection will be provided for transition <br />of flows and for critical areas such as swales and curves when excessive velocities <br />are anticipated. <br />(c) Energy dissipators will be installed when necessary, such as at discharge points, <br />where diversions intersect with natural streams and exit velocity of the diversion flow <br />is greater than that of the receiving stream. <br />(d) Excess excavated material not necessary for diversion channel geometry or <br />regrading of the channel will be disposed of in accordance with 4.09. <br />(e) Topsoil will be handled in compliance with 4.06: <br />(f) All ditches, culverts and diversions will be temporary, therefore peak flows will be <br />designed for the 10 year 24 hour event of 2.0 inches. <br />As shown on Map 2.05.3-1, the permit area has been divided into many collection ditch and culvert <br />basins. All ditches, culverts and their respective watershed basins are labeled on the map. Most of <br />the culverts are needed to get disturbed areas under roads to the downstream collection ditch or <br />sediment pond. <br />Designs for all ditches west of 27.00 Rd: <br />Designs for all ditches west of 27.00 Rd were accomplished in the following steps: <br />1) using a 3D grid of the watershed, the actual area and average land slope was <br />developed. <br />2) along flow line was drawn from the top of each watershed to the bottom of the ditch. <br />3) using the SCS Method provided within SURVCADD, the time of concentration was <br />developed for each watershed. <br />• (REVISED 7/2004 2.05.3(3) - 4 <br />