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APPENDIX M viii <br />• SMALL AREA EXEMPTION # 2 - SAE Z 3 <br />LOMA LOADOUT SURFACE WATER CONTROLS <br />To control the runoff of water and sediment from the loadout, a <br />berm has been constructed on the south side of the area. In <br />accordance with applicable regulations, these calculations will show <br />that the sediment containment structures are capable of retaining <br />the entire volume of the design storm. <br />The loadout is a strip of Land up to ?5 feet wide. The area that <br />drainage must be controlled is about 1300 feet long. The slope of <br />the area is about 2% down from the track to the berm on the south <br />side. Water will be retained up to one foot high in the detention <br />area that is about 300 feet long. <br />SPECIFICATIONS <br />Area = 97,500 sgft = 2.24 acres Ave Slope = 2~ <br />Soil Type = mixed use Group = C <br />Length = 200 ft Veg. cover = 0~ <br />PEAK FLOW CALCULATIONS <br />1. From "Peak Flows In Colorado" Pio = I.4" <br />Z. Runoff: CN disturbed use CN = 87 <br />• RUNOFF IO yr Pe= 0.47"' <br />3. For Area =,10 acre & Slope = 2~ Slope Adj. Factor = 1.20 <br />4. Assume that Actual Area = Equivalent Area <br />Therefore, Actual area/Equivalent Area = 1.00 <br />5. For CN =87 and Area = 2.24 ac Oa is about 2.8 cfs/inch <br />6. Equivalent discharge qio = Z.8#0.47"#I.ZO = 1.58 cfs <br />7. The ACTUAL DZSCHARGfi is: Qio = 1.58 cfs <br />8. The VOLUME DISCHARGED is: Vio = 0.47"# 97,500ft/12 <br />Vio = 3,818 tuft <br />SIZE OF THE SEDIMENT TRAP <br />The detention area is triangular in cross section 1 foot high and <br />50 feet wide and 300 feet long. <br />The Volume of the Trap = 0.5 * base * height * length <br />Volume = 0.5 * 50' * 1' * 300' = 7,500 cubic feet <br />The trap will retain the entire volume of a IO year, 24 hour <br />precipitation event. <br /> <br />M(viii) - 2 6/28/91 <br />