Agenda - 03-04-2004-9a - Laserfiche WebLink

Browse Search

Hillsborough State Employees Credit Union Stormwater Report ~ -'] Project # 70994252 Computer Model Input for Watershed Areas Through the use of HydroCAD, many aspects of the effluent flow were analyzed. The program requires certain input regarding the characteristics of the land. The input required is:• 1. Design Storm Information a. Length of storm b. Depth of rainfall • e. Time increment for analysis (dt) 2. Time of Concentration 3. Composite Areas with Corresponding SCS Runoff Curve Numbers esien forms An SCS Type II 24 Hour rainfall distribution was assumed for the storm analysis, with 0.01-hour increments. A rainfall of 3.00 inches was used for the one-yeaz storm analysis. For the 10-year stomp,-5.38 inches of rainfall was used. Time. of Concentration The tune of concentration route was identified as the longest path that water would flow to reach the pond. Each route was broken into twa segments: sheet flow and shallow concentrated flow. TR55 methods wtre used to calculate the sheet and shallow concentrated flow times, through the HydroCAD program. • Composite Areas and Correspondin¢ SCS Runoff Curve Nurr-bers The composite areas were entered into HydroCAD using measurements taken from the design drawings. The corresponding SCS curve numbers were selected based on the surface composition, and can be seen in the HydroCAD reports included in Appendix A. • Summary After cazefuI consideration of the pre and post development conditions at the Hillsborough State .-...:. zp _ y - n; - with the Orange Gounty Inspections Department, Lan cape - --- ` -' - =- ".Hit is ees Credit Unio -discussions - _- .. •- - - ~_- ~ Arclutccts-`from--O'Brien- =Atkins, --aIId=after=ttaking _ _eoncexns~for.:_tha ~u~aunding _watershed into consideration, the proposed-stormwater plan was-.developed_ Tfus-p~ari`in`coiporates-the-•existing ---_-- stormwater structures and the addition of a new underground detention system. -. - nR/O8/03 Page 2