complete drainage report rev 9

Docusign Envelope ID: E802A2F1-2485-417E-948D-E0A4008C75BD Point of Analysis 3 Point of analysis 3 discharges to an existing drainage system in Howell Drive. This municipal system flows to the east away from the onsite streams. This drainage area is only for disturbance associated with one half of the emergency access road which will be gated closed and will have little vehicle traffic. The design achieves stormwater management standards of quality, quantity and recharge with the use of filterra water quality devices discharging to a small scale subsurface infiltration basin with soil replacement. The system recharges the entire volume of the 100 yr storm to the ground. An emergency overflow to the municipal system is provided. The proposed Tc is calculated as follows: 50 lf sheet flow @ 12% grass Tc = 3.8 60 lf @ 12% grass swale Tc= .2 Total Tc = 4 minutes. PA-3 Summary STORM 2 10 100 EXISTING .13 .32 .75 PERMITTED .07 .22 .60 BASIN 12 0 0 0 TOTAL 0 0 0 ` Conclusion The design of the West Essex Highlands Project has been completed in accordance with the court approved resolution with the limiting of the area of disturbance below 30 acres and the inclusion of environmentally friendly designs that are sensitive to the existing environmental constraints. The stormwater design includes green technology for water quantity, quality and seeks to optimize the volume groundwater recharge with green technology. The overall discharge has been conservatively calculated for each drainage basin and overall and meet the discharge standards as required in the state standards and municipal ordinance. 12