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a) Most ditches will not need to be lined, however, any stretch of collection ditch which has <br />a velocity above 5.5 feet per second will be lined. Channel linings, including channel <br />riprap, will be designed using standard engineering practices to pass safely the design <br />velocities. These velocities assume the typical silty loam soil conditions on site. If better <br />conditions exist, the velocities will be allowed to increase without lining. If worse <br />conditions exist, lining may be needed for lower velocities. <br />b) Freeboard will be a minimum of 1.0 feet. Protection will be provided for transition of <br />flows and for critical areas such as swales and curves when excessive velocities are <br />anticipated. <br />c) Energy dissipators will be installed when necessary, such as at discharge points, where <br />diversions intersect with natural streams and exit velocity of the diversion flow is greater <br />than that of the receiving stream. <br />d) Excess excavated material not necessary for diversion channel geometry or regrading of <br />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 />Ditches designs are presented in several different appendices and are further outlined below by <br />the appropriate stationing on the ditches. <br />Appendix 2.05.3(4)-1 contains ditch design information for the NHN-001 East Ditch from <br />station 0+00 to 4+88 as shown on Map 2.05.3(4)-11. Appendix 2.05.3(4)-1 also contains all the <br />ditch design information from the NHN-003 North and South Ditches. Please refer to Figure 1 <br />in Appendix 2.05.3(4)-1 for the NHN-003 ditch locations. <br />Appendix 2.05.3(4)-7 contains ditch design information for the NHN-001 West Ditch from <br />stations 0+00 to 12+25, and for the NHN-001 East Ditch from stations 0+00 to 27+11. Please <br />see Map 2.05.3(4)-7 for these ditch locations. <br />Appendix 2.05.3(4)-8 contains ditch design information for all of the NHN-002 North and South <br />Ditches. Please see Map 2.05.3(4)-9 for ditch and watershed locations. <br />Appendix 2.05.3(4)-11 contains the design information for the NHN-00 East Ditch Extension <br />from station 4+88 to 10+79. <br />Sedimentation Ponds <br />In accordance with Rule 4.05.2NHN will use Ponds NHN-001, NHN-002 and NHN-003 to <br />prevent, to the extent possible, additional contributions of sediment to stream flow or runoff <br />Section 2.05.3(4) Page 3 April 2016 (TR -13) <br />