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I <br />With the physical features of each basin now <br />numerically defined, the "Runoff" Block provided with the <br />SWMM program was used to generate runoff hydrographs for <br />the referenced storm events. <br />3.1 SIMPLIFYING ASSUMPTIONS <br />The SWMM program requires specific information concerning <br />the physical characteristics of the site such as <br />infiltration capacity, depression storage for pervious <br />and impervious areas, evaporation rates, etc. This <br />information was not readily available at the time <br />modeling was conducted. Therefore, assumptions were <br />made for these parameters as follows. Impervious <br />depression storage was set at 0.0 inches. Pervious <br />depression storage was estimated to be 0.015 inches. The <br />maximum and minimum infiltration rates were estimated at <br />0.15 in/hr and 0.005 in/hr respectively. The decay rate <br />for the Horton infiltration equation was set at <br />-1 <br />0.0011115 seconds Snowmelt information was not <br />considered in this study. <br />7 <br />