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1.7+Vw <br />• X =~\^% <br />Where: Vw =weighted average velocity in fps of all the flow <br />segments from the subwatershed outlet to the structure <br />K =summation of the travel time for each flow segment <br />Where: Travel time is calculated by using the SCS Upland Method as <br />presented in Barfield, et al., page 100, and in the same manner <br />as is Time of Concentration, as previously described. <br />SEDIMENTOLOGY <br />Sediment yield was calculated by SEDCAD+ for single storm events and <br />converted to annual yields by the following equation: <br />V = R,~~,,,, x (Storm sediment yield)x(~ x 2000 IbS~ton <br />• R„o,,,, SW 43,560 ft~/acre <br />Where: V =Annual Sediment Volume (acre ft/year) <br />R,~,„w =Annual Rainfall Factor <br />R,,,,,,, =Single Storm Rainfall Factor <br />SW =Sediment Specific Weight (Ibs/ft') <br />Annual and storm rainfall factors and sediment specific weight are explained in <br />detail under SEDCAD+ Sedimentology Inputs. The storm sediment yield (tons) <br />is a SEDCAD+ output, calculated as described below. <br />SEDCAD+ Sediment Calculations <br />The sedimentology of each watershed was evaluated by SEDCAD+. <br />SEDCAD+ develops a sedimentgraph utilizing the Revised Universal Soil Loss <br />Equation using a new revised representative length-slope factor as follows: <br />• Y = 95(V x QP)°''~K(LS)(CPj <br />s <br />