12 2026 02 12 Crestmont CC Stormwater Management Report

CRESTMONT COUNTRY CLUB EAGLE ROCK AVE IMPROVEMENTS LANGAN PROJECT #101049802 TOWNSHIP OF WEST ORANGE, NJ EXISTING RUNOFF CURVE NUMBER CALCULATIONS CRESTMONT COUNTRY CLUB & EAGLE ROCK AVE IMPROVEMENTS LANGAN PROJECT #101049802 EXISTING CONDITIONS EXISTING OPEN SPACE OPEN SPACE WOODS WOODS GRAVEL GRAVEL OPEN SPACE OPEN SPACE WOODS WOODS GRAVEL GRAVEL IMPERVIOUS IMPERVIOUS TOTAL TOTAL CURVE WATERSHED HSGC C HSGC C HSGC C HSGC C HSGC C HSGC C HSGC D HSGC D HSGC D HSGC D HSGC D HSGC D AREA AREA AREA AREA NUMBER AREAS CN = 74 CN = 74 CN = 70 CN = 70 CN = 89 CN = 89 CN = 80 CN = 80 CN = 77 CN = 77 CN = 91 CN = 91 CN = 98 CN = 98 CN (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF)

CN (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (Weighted) POA-1 EX-1-DISTURBED 0 0.00 0 0.00 0 0.00 28,385 0.65 33,979 0.78 0 0.00 3,969 0.09 66,333 1.52 80 EX-1-UNDISTURBED 59,295 1.36 30,440 0.70 0 0.00 0 0.00 0 0.00 0 0.00 128,036 2.94 217,771 5.00 88 POA-2 EX-2-DISTURBED 0 0.00 0 0.00 0 0.00 17,805 0.41 44,242 1.02 2,900 0.07 39,818 0.91 104,765 2.41 86 EX-2-UNDISTURBED 37,228 0.86 41,197 0.95 3,700 0.08 0 0.00 0 0.00 0 0.00 45,766 1.05 127,891 2.94 82 NOTES: 1. Runoff curve numbers referenced from Technical Release 55 (TR-55) Table 2-2a: Runoff Curve Numbers for Urban Areas and Table 2-2c: Runoff Curve Numbers for Other Agricultural Lands. Pervious areas are assumed to be in good hydrologic condition. \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Eagle Rock Ave Watershed CN Calculations