Laserfiche WebLink
Overflow Riser <br />The overllow riser was designed to flow the 100-year undetained developed storm event <br />(Q�� = 17.77 cfs) with 0.75 ft of head (H � 0.75 ft). Figure 4.4.7J, Riser Inflow Curv�, <br />located in the Appendix was used to siu the riser diameter required. Since Q�� = 17.77 <br />cfs, the required riser diameter is 36 inches. The following calwlation is to check the <br />capacity of a 36 inch diameter riser: <br />I Q,,;,, = 9.739 x D x H'� <br />Q,,;R = 18.98 cfs <br />{>17.77 cfa (OK)} <br />Overflow Spiliway <br />The overtlow spillway was designed to flow the 100-year undetained developed stortn <br />event (Q�oo = 17.77 cfs) with 0.5 ft of head (H = 0.5 ft). The following is the calculation <br />to detemrine the reyuired length of the overflow spillway: <br />L=(Q��/ (3.21 x H3�)) -(2.4 x H2) <br />i L=(17.77 /(3.21 x 0.5'�)) -(2.4 x 0.52) <br />L = 15.06 ft <br />The actual length of the spillwAy is 20 ft, which will flow up to 23.38 cfs with 0.5 ft of <br />head. <br />ISTORM DRAINAGE REPORT FOR VIKING FREIGHT/IuIERRILL CREEK PAGE 8 <br />