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• structure. If the subwatershed is located at the structure. K and X are <br />equal to zero. The methodology outlined in the SEDCAD+ User's Manual 1s <br />used to calculate these two (2) routing parameters. The specific <br />equations and values used are detailed as follows: <br />X O.SVw <br />)~w <br />Where: Vw = weighted average velocity in fps of all the. flow <br />segments from the subwatershed outlet to the <br />structure <br />K =summation of the travel times for each flow <br />segment <br />Where: Travel time is calculated by using the SCS Upland <br />Method as presented in Barfield, et al., page 100, <br />• and in the same manner as is Time of Concentration, <br />as previously described. <br />SEDIMENTOLOGY <br />Sediment yield was calculated by SEDCAD+ for single storm events and <br />converted to annual and 3-year yields by the following equation: <br />V3yr ^' Rannual x(Storm sediment yield)x( 1)x(3 years) <br />Annual and storm rainfall factors and sediment specific weight are <br />explained 1n detail under SEDCAD+ Inputs. The storm sediment yield is a <br />. SEDCAD+ output. calculated as described below. <br />Rsto SW <br />Where: V3yr ^ 3 year sediment volume <br />Rannual = Annual Rainfall Factor <br />Rstorm Single Storm Rainfall Factor <br />SW Sediment Specific Weight <br />23-66 <br />