2025 12 19 Stormwater Report Rev 1

The entire site is mapped with soils considered Hydrologic Group D (See attached Appendix for Soil Map). For this analysis, all the drainage areas were assumed to have 0.99 as a Runoff Coefficient (C value), which is the most conservative value. CONCLUSION The proposed improvements meet all of the stormwater management regulations for both the Township of West Orange as well as the NJDEP. The stormwater quantity is satisfied through the use of non-structural strategies, specifically the reduction in impervious surfaces. The proposed development calls for the reconstruction of the existing parking lot, increasing the amount of landscape area by approximately 0.16 acres. The decrease in impervious also means that water quality measures are not required. The site is located in the Metropolitan Planning Area, which means that stormwater recharge is not required. 9