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

Hydrograph 100-yr Summary File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (hrs) (cuft) (ft) (cuft) 1 NRCS Runoff EX-1-D Open Space D 3.834 12.20 16,035 ---- 2 NRCS Runoff EX-1-D Woods D 4.396 12.20 18,185 ---- 3 NRCS Runoff EX-1-D Impervious 0.818 12.12 3,032 ---- 4 Junction EX-1-D 8.751 12.18 37,253 1, 2, 3 6 Diversion1 EX-1-D 2 YR ALLOW 4.376 12.18 18,626 4 7 Diversion2 <name> 4.376 12.18 18,626 4 8 Diversion1 EX-1-D 10 YR ALLOW 6.563 12.18 27,940 4 9 Diversion2 <name> 2.188 12.18 9,313 4 10 Diversion1 EX-1-D 100 YR ALLOW 7.001 12.18 29,802 4 11 Diversion2 <name> 1.750 12.18 7,451 4 13 NRCS Runoff EX-1-U Open Space C 7.542 12.18 29,392 ---- 14 NRCS Runoff EX-1-U Woods C 3.591 12.18 13,875 ---- 15 NRCS Runoff EX-1-U Impervious 26.72 12.12 99,046 ---- 16 Junction EX-1-U 36.55 12.12 142,313 13, 14, 15 18 Junction TOTAL POA-1 44.56 12.13 179,566 4, 16 19 Junction POA-1 2 yr Allow 40.46 12.12 160,939 6, 16 20 Junction POA-1 10 yr Allow 42.50 12.13 170,253 8, 16 21 Junction POA-1 100yr Allow 42.92 12.13 172,115 10, 16 25 NRCS

Junction POA-1 10 yr Allow 42.50 12.13 170,253 8, 16 21 Junction POA-1 100yr Allow 42.92 12.13 172,115 10, 16 25 NRCS Runoff EX-2-D Open Space D 2.418 12.20 10,115 ---- 26 NRCS Runoff EX-2-D Woods D 5.749 12.20 23,781 ---- 27 NRCS Runoff EX-2-D Gravel D 0.647 12.10 2,071 ---- 28 NRCS Runoff EX-2-D Impervious 8.657 12.10 29,728 ---- 30 Junction EX-2-D 15.92 12.12 65,695 25, 26, 27, 28 31 Diversion1 EX-2-D 2 YR ALLOW 7.962 12.12 32,847 30 32 Diversion2 <name> 7.962 12.12 32,847 30 33 Diversion1 EX-2-D 10 YR ALLOW 11.94 12.12 49,271 30 34 Diversion2 <name> 3.981 12.12 16,424 30 35 Diversion1 EX-2-D 100 YR ALLOW 12.74 12.12 52,556 30 36 Diversion2 <name> 3.185 12.12 13,139 30

Hydrograph 100-yr Summary File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (hrs) (cuft) (ft) (cuft) 38 NRCS Runoff EX-2-U Open Space C 4.208 12.23 18,667 ---- 39 NRCS Runoff EX-2-U Woods C 4.295 12.23 18,911 ---- 40 NRCS Runoff EX-2-U Gravel C 0.695 12.12 2,368 ---- 41 NRCS Runoff EX-2-U Impervious 9.544 12.12 35,374 ---- 42 Junction EX-2-U 16.94 12.13 75,319 38, 39, 40, 41 44 Junction TOTAL POA-2 32.74 12.12 141,014 30, 42 45 Junction POA-2 2YR ALLOW 24.78 12.12 108,167 31, 42 46 Junction POA-2 10YR ALLOW 28.76 12.12 124,590 33, 42 47 Junction POA-2 100YR ALLOW 29.56 12.12 127,875 35, 42

FUTURE HYDROGRAPH CALCULATIONS

EX-1-DISTURBED WATERSHED

Project: Eagle Rock Avenue By: TEG Date: 10/20/2025 Location: West Orange, NJ Checked By: MJV Date Checked: 10/20/2025 Circle One: Present Developed Future Existing Watershed EX-1-D Impervious Circle One: Tc Tt through subarea Include a map, schematic, or description of flow segments. Sheet Flow (Applicable to Tc Only) Segment ID 1 1. Surface Description (NEH table 15-1) Smooth Surfaces 2. Manning's Roughness Coeff., n (NEH table 15-1) 0.011 3. Flow Length, L (total L < 100 ft) ft 85 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.043 0.8 6. Compute Tt 0.007 (nL) hr 0.012 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.012 hours Shallow Concentrated Flow Segment ID 2 3 7. Surface Description Woodlands Pavement 8. Flow Length, L ft 117 465 9. Watercourse Slope, s ft/ft 0.207 0.018 10. Average Velocity, V (NEH table 15-3) ft/s 2.29 2.75 11. Compute Tt L hr 0.014 +

ft/s 2.29 2.75 11. Compute Tt L hr 0.014 + 0.047 + Tt = 3600 V Shallow Conc. Flow Sub-Total 0.061 hours Channel Flow Segment ID 4 5 12. Flow Length, L ft 15 51 2 13. Cross Sectional flow area, a ft 0.61 0.61 14. Wetted Perimeter, Pw ft 2.00 2.00 15. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 16. Channel Slope, s ft/ft 0.055 0.021 17. Manning's Roughness Coeff., n 0.013 0.013 2/3 1/2 18. Velocity, V V = (1.49 r s ) / n ft/s 12.14 7.59 19. Compute Tt L hr 0.000 + 0.002 + Tt = 3600 V Channel Flow Sub-Total 0.002 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.075 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 5 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site

steps) Total Tc (minutes) = 5 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Future Existing TC EX-1-D Impervious v1.2

Project: Eagle Rock Avenue By: TEG Date: 10/20/2025 Location: West Orange, NJ Checked By: MJV Date Checked: 10/20/2025 Circle One: Present Developed Future Existing Watershed EX-1-D Pervious Circle One: Tc Tt through subarea Include a map, schematic, or description of flow segments. Sheet Flow (Applicable to Tc Only) Segment ID 1 2 Woods Dense Woods Dense 1. Surface Description (NEH table 15-1) Underbrush Underbrush 2. Manning's Roughness Coeff., n (NEH table 15-1) 0.40 0.40 3. Flow Length, L (total L < 100 ft) ft 72 28 4. Two-year 24-hr rainfall, P2 in 4.08 4.08 5. Land Slope, s ft/ft 0.070 0.281 0.8 6. Compute Tt 0.007 (nL) hr 0.147 + 0.040 + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.187 hours Shallow Concentrated Flow Segment ID 3 4 7. Surface Description Woodlands Pavement 8. Flow Length, L ft 58 222 9. Watercourse Slope, s ft/ft

L ft 58 222 9. Watercourse Slope, s ft/ft 0.272 0.027 10. Average Velocity, V (NEH table 15-3) ft/s 2.63 3.31 11. Compute Tt L hr 0.006 + 0.019 + Tt = 3600 V Shallow Conc. Flow Sub-Total 0.025 hours Channel Flow Segment ID 5 6 12. Flow Length, L ft 15 51 2 13. Cross Sectional flow area, a ft 0.61 0.61 14. Wetted Perimeter, Pw ft 2.00 2.00 15. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 16. Channel Slope, s ft/ft 0.055 0.021 17. Manning's Roughness Coeff., n 0.013 0.013 2/3 1/2 18. Velocity, V V = (1.49 r s ) / n ft/s 12.14 7.59 19. Compute Tt L hr 0.000 + 0.002 + Tt = 3600 V Channel Flow Sub-Total 0.002 hours Watershed or subarea Tc or Tt