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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />The low hazard thunderstorm for desi gn purposes is the I-hour <br />assumption "B" thunderstorm which would most probably occur in July or <br />August (Reference 1). The I-hour rainfall depth over the basin is 2.0 <br />inches (refer to Table A-2 in Appendix A). A Runoff Curve Number (SCS <br />procedure) of 74 was used to determine the inflow hydrograph for the <br />Assumption B thunderstorm. The peak flow for the I-hour thunderstorm <br />inflow flood is 662 cfs, with a runoff volume of 50 acre-feet. <br /> <br />D. Reservoir Routing of IDF's <br /> <br />The inflow design floor hydrographs for the laO-year 6-hour and <br />18-hour storms and the Assumption B thunderstorm were routed through <br />the existing reservoir and spillway. The basic routing data are pre- <br />sented in Table A-3 in Appendix A. The beginning water surface 'eleva- <br />tion used in the reservoir routings is 202.2 feet (gage height 17.2 <br />feet). The results of the reservoir routings for existing conditions <br />are summarized in Table 2. <br /> <br />- V-6 - <br />