complete drainage report rev 9

Docusign Envelope ID: E802A2F1-2485-417E-948D-E0A4008C75BD PA-1 Discharge Summary STORM WQ 2 YR 10 YR 100 YR EXISTING 7.08 15.93 35.21 PERMITTED #1 #5 #6 3.54 11.15 28.17 0 .75 3.24 12.27 0 0 1.06 4.67 0 0 .13 3.02 OVERLAND FLOW .43 2.33 4.75 9.71 POA 1 .43 2.36 5.27 14.86 Point of Analysis 2 This drainage area discharges to the Canoe Brook Tributary which exists at the site between the Kusik Dr and Warner Road entrance to the property. The stormwater management systems in this drainage area are small scale infiltration basins 2 , 7 & 10 and porous pavement systems 3,4, 8, &11. Each of these systems are considered green technology for quantity, quality and recharge. Small Scale Infiltration Basin 2 This stormwater system collects water from the parking lot and grass areas behind Building A. The total contributory area is 2.49 acres. The system will have soil replacement with a permeability of 4 inches per hour with a factor of safety of 2. The proposed Tc for the area flowing to Basin 2 uses the following input Sheet flow 93lf @5% over grass Tc= 9 minutes Shallow concentrated flow 370 lf over pavement @ 6.5% Tc = 1.5 minutes Total Tc = 10.5 minutes The small-scale infiltration basin is considered green technology for both groundwater recharge and water quality. 7