Laserfiche WebLink
r~ <br />u <br />• <br />n <br />f. J <br />* The numerator and denominator in average ditch slope for C-9, C-10 and C-11 designate two distinct <br />ditch lengths, the mild portion and the steep portion. The steep portion for these ditches will be wider <br />in the case of Ditch C-9 or lined with cobbles/shingles, as in the case with ditches C-10 and C-11. <br />Cobbles and Shingles have a manning's n of 0.035 which reduces the velocity to acceptable levels. In <br />installation, the cobbles/shingles may be substituted by durable rock of D50 of 8" size. These special <br />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 <br />of this ditch will have no lining. <br />The following pages show the detailed calculations for all ditches. <br />3. DITCH DESIGNS <br />DITCH C-1 <br />Time of Concentration (SCS Method) <br />Curve Number: 86 <br />Length of Flow (ft): 2610.41 <br />Average Land Slope (percent): 9 <br />Time of Concentration (hrs): 0.31 <br />Graphical Peak Discharge <br />Project: NUCLA MINE <br />Location: DITCH C-1 <br />Developed <br />1. Data: <br />By: GL Date: 02/16/06 <br />Checked: Date: <br />Drainage area :....................A = 25.7000 Acres <br />REVISED MARCH 2006 <br />Attachment 2.05.3(3)-1-8 <br />