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• <br />~~ A~dV~B~Tllh ~~' <br />~~ 4•SF-06 <br />' SITE PREPARATION & DRAINAGE <br />esawu aa-eorsataucroaa <br />STANDARD FORM REV. 1 <br />uir urea em, ~aH <br /> RUNOFF & SEDIMENT CALCULATIONS 9/80 <br /> SHT. 50F 12 <br />DETERMINATION OF SEDIMENT VOLUME, SETTLING VOLUME <br />AND TOTAL STORAGE VOLUME OF SEDIMENTATION PONDS <br />PROJECT •UESE/PfI DD /J7/NE Jos No. U~39~ <br />/t?EF(/~'E A/P~.9 ~ / POND N0. ,qP -I <br />BY t~/Y1G(I DATE q'30-~0 CHECKED BY DATE _ <br />6. Peak Rate of Discharge -Used to Design Emergenry Spillway, Road Culverts and Interceptor Ditches <br />Drainage Area = ZS-3 Acres <br />Hydraulic Length = 0"20 ~ Feet <br />Equivalent Drainage Araa = -2~~ Acres (Fig. 7 ; TP-149) <br />Average Watershed Slope = /Z% y, <br />Weighted Watershed Runoff Curve Number = ~~~ 9 <br />A. Peak Rate of Discharge From Charts ES-1026, ES-1027, TP-149 <br />.. <br />Rainfall Frequenry = /~ Years Rainfall Depth = ~'8 Inches <br />011 Far~~ RCN11 = 01ES 102_for STEEP slopes) x Slope Correction Factor (Ex. 2.0) <br />a2 x -96 ~ 2/-~ cfs <br />021For g5 RCN21 = -3 ~ x ~ 96 = 3s•s cfs <br />Equivalent Discharge = ~6'~ cfs (Interpolate Between 01 and D21 <br />Actual Peak Discharge =Equivalent Discharge x Actual Drainage Area <br />Equivalent Drainage Area <br />Actual Peak Discharge ~G'~ x ( 25.3 1 = /S•0 cts <br />99-0 <br />Note: 0~ and 0~ above refer to runoff resulting from RCN's to nearest 5 (60, 65, 70, etc.) <br />If eompufed RCN ends in 0 or 5 (60, 65, 70, etc.) , 02 and the next line will not <br />be needed. In this case, 0~ runoff will be the equivalent Discharge. Refer to <br />SCS•TP-149 and Engineering Field Manual, Chapter 2. <br />Type I Storm distribution ES-1026: Hawaii, Alaska coastal side of Sierra Nevada <br />and Cascade Mountains in California, Oregon and Washington. <br />Type II Storm distribution ES•1027: rest of United States, Puerto Rico, and <br />the Virgin Islands. <br />10-80 <br />