EX Pool 8 Full Matarrazo Drainage System Approved by Town 3623

METHODOLOGY The SCS Method for estimating stormwater runoff was used for this analysis. The existing drainage area was analyzed as being completely undeveloped as if the house was not yet constructed. The reasoning for this is that at the time the house was constructed, drywells were installed for the roof leaders. The post-developed drainage area includes the house, cabana, pool and patio areas, and is considered as being all impervious. The surface area of the swimming pool is also being considered as impervious. This is a conservative assumption since the pool surface area would actually capture and contain storm water rainfall and not contribute to runoff volume. Roof leader drains from the existing house will also be connected to the storm drainage system. The drywell system consists of 10 drywells surrounded by gravel. Stormwater from the drywell system flows into a proposed outlet structure. Routing calculations were performed for the 2, 10, and 100 year storm scenarios. The drywell system is designed as a dry basin, meaning that it is intended to completely drain after each storm event, except for a 1 ft depth below the lowest orifice of the outlet structure. Any infiltration that would occur in this system is not being considered in order take a conservative approach to the design. ME Matarazzo ==|Engineering 575 Route 46 West Fairfield, New Jersey 07004 Phone: (973) 808-8779 Fax: (973) 808-8789 RESPONSE TO OPRA 2024-53_ 000006