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Table 2.05.3(3)-i Collection <br />Ditch and <br />Diversion Ditch Designs Entire Permit Area <br />Structure <br />Watershed <br />Basin(s) <br />Watershed <br />Area <br />(acres) <br />Watershed <br />% Avg. <br />Slope <br />Runoff <br />Curve <br />No. <br />Design <br />Storm <br />(yrs) <br />Time of <br />Conc. <br />(hrs) <br />Peak <br />Flow <br />(cfs) <br />Avg. <br />Ditch <br />Slope % <br />Ditch <br />Bottom <br />Width (ft) <br />Ditch <br />Depth (ft) <br />Velocity at <br />Design Flow <br />(ft/sec) <br />Comments <br />C32 <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />Removed <br />C33 <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />Replaced with straw <br />wattles, see Section 5 <br />D1W <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />I N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />Removed <br />D108 <br />18 <br />41.7 <br />6.4 <br />78 <br />10 <br />0.50 <br />10.7 <br />2.6 <br />2.0 <br />0.68 <br />4.7 <br />Mostly offsite undisturbed <br />area with ponding <br />D109 <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />N/A <br />Removed <br />*The numerator and denominator in average ditch slope for C11 designate two distinct ditch lengths, the mild portion and the steep portion. The steep portion for these <br />ditches will be lined with cobbles/shingles. Cobbles and Shingles have a manning's n of 0.035 which reduces the velocity to acceptable levels. In installation, the <br />cobbles/shingles may be substituted by durable rock of D50 of 8" size. These special ditch sections are shown on Map 2.05.3(3)-1. <br />Ditch C20 will have lining of D50 of 8" size for 20' length on either side of Culvert 112. The remainder of this ditch will have no lining. <br />Attachment 2.05.3(3)-1 Page 9 March 2016 (TR -70) <br />