2026 02 12 Crestmont CC and Eagle Rock Ave Stormwater Management Report

CRESTMONT COUNTRY CLUB EAGLE ROCK AVE IMPROVEMENTS LANGAN PROJECT #101049802 TOWNSHIP OF WEST ORANGE, NJ PROPOSED RUNOFF CURVE NUMBER CALCULATIONS CRESTMONT COUNTRY CLUB & EAGLE ROCK AVE IMPROVEMENTS LANGAN PROJECT #101049802 PROPOSED CONDITIONS PROPOSED CONDITIONS OPEN SPACE OPEN SPACE WOODS WOODS GRAVEL GRAVEL OPEN SPACE OPEN SPACE WOODS WOODS 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 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 = 98 CN = 98 CN (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (Weighted) POA-1 PR-1A-DISTURBED 0

) (AC) (SF) (AC) (SF) (AC) (SF) (AC) (Weighted) POA-1 PR-1A-DISTURBED 0 0.00 0 0.00 0 0.00 14,616 0.33 0 0.00 13,749 0.32 28,365 0.65 89 PR-1A-UNDISTURBED 14,197 0.33 3,545 0.08 0 0.00 0 0.00 0 0.00 21,867 0.50 39,609 0.91 87 PR-1B-DISTURBED 0 0.00 0 0.00 0 0.00 14,998 0.35 0 0.00 146 0.00 15,144 0.35 80 PR-1B-UNDISTURBED 12,719 0.29 26,663 0.62 0 0.00 0 0.00 0 0.00 51,618 1.18 91,000 2.09 86 PR-1C-DISTURBED 0 0.00 0 0.00 0 0.00 14,133 0.32 0 0.00 4,828 0.11 18,961 0.44 85 PR-1C-UNDISTURBED 31,706 0.73 0 0.00 0 0.00 0 0.00 0 0.00 48,875 1.12 80,582 1.85 89 POA-2 PR-2A-DISTURBED 0 0.00 0 0.00 0 0.00 34,997 0.80 0 0.00 18,381 0.42 53,378 1.22 86 PR-2A-UNDISTURBED 7,960 0.18 7,646 0.18 0 0.00 0 0.00 0 0.00 29,520 0.68

0.18 7,646 0.18 0 0.00 0 0.00 0 0.00 29,520 0.68 45,126 1.04 89 PR-2B-DISTURBED 0 0.00 0 0.00 0 0.00 1,485 0.03 0 0.00 16,015 0.37 17,500 0.40 96 PR-2B-UNDISTURBED 305 0.01 0 0.00 0 0.00 0 0.00 0 0.00 1,247 0.03 1,552 0.04 93 PR-2C-DISTURBED 0 0.00 0 0.00 0 0.00 25,256 0.58 0 0.00 12,494 0.29 37,749 0.87 86 PR-2C-UNDISTURBED 29,536 0.68 33,782 0.77 3,700 0.08 0 0.00 0 0.00 20,774 0.48 87,792 2.01 79 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