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<br />-.; <br /> <br />II <br />II <br />II <br />II <br />I <br />II <br />I <br />-- <br />I <br />I, <br />II <br />1 <br />,- <br />,- <br />II <br />[ <br />,- <br />. <br />[ <br />. <br />~ <br /> <br />total area within each basin associated with a specific hydrologic soil group and native <br />plant community. In addition, existing and future developed areas were delineated in the <br />base map so that appropriate Curve Numbers could be assigned to developed areas as <br />welL This information was entered into the PondPack program, and weighted Curve <br />Numbers were calculated for each basin. Appendix A, Hydrologic Basin Data, consists of <br />a table detailing the hydrologic and land-use parameters by basin. Appendices B&C <br />consist of a summary (generated by PondPack) of the existing and future composite <br />Curve Numbers (by basin), respectively. <br /> <br />VI. Time of Concentration <br /> <br />The flow-paths used to calculate the times of concentration are shown on Figure 2. Times <br />of Concentration for each basin were calculated primarily by PondPack using the -TR-55 <br />equations for sheet flow, shallow concentrated flow, and channel flow. Exceptions <br />occurred when flow-paths occurred in gutters. Tq.e times of concentration for gutter flow <br />segments were calculated assuming, a velocity between 3 to 4 fps, depending on the slope <br />of the gutter. When it was necessary to calculate times of concentration for channel flow <br />segments, assumptions were made about the magnitude of flow and channel <br />characteristics such as cross-section and slope were entered into Flow Master (Haested <br />Methods) to obtain an estimate of for the flow area and wetted perimeter. The <br />calculations for times of concentration are included as Appendix D. <br /> <br />VII. Results <br /> <br />Models were run for existing and future conditi,?ns. Refer to Appendix E for the model <br />schematics. The elements of the' model schematics, namely j~ctions and ponds, are <br />included on Figure 2. A summary of the existing and future conditions model results are <br />included as Appendices F&G, respectively. Appendix Ii contains the lOO-year future <br />conditions hydrographs for each basin as well as the hydrographs for the major basins at <br />the outfalls. The accompanying CD contains text files with tabular hydrographs for all <br />storm events as well as the PondPack models. <br /> <br /> <br />\,j <br /> <br />2 <br />