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

ft2 0.61 0.61 23. Wetted Perimeter, Pw ft 2.00 2.00 24. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 25. Channel Slope, s ft/ft 0.055 0.021 26. Manning's Roughness Coeff., n 0.013 0.013 2/3 1/2 27. Velocity, V V = (1.49 r s )/n ft/s 12.14 7.59 28. 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) = 0.096 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 6 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Proposed Tc Calcs\Current Proposed TCs\Current Proposed TC PR-1B-D Pervious v1.4

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-D Hyd. No. 13 Hydrograph Type = NRCS Runoff Peak Flow = 0.680 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 2,102 cuft Drainage Area = 0.35 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 6.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.680 cfs 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 Q (cfs) 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Time (hrs)

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-D Hyd. No. 13 Hydrograph Type = NRCS Runoff Peak Flow = 1.356 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 4,228 cuft Drainage Area = 0.35 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 6.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.356 cfs 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 Q (cfs) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Time (hrs)

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-D Hyd. No. 13 Hydrograph Type = NRCS Runoff Peak Flow = 1.842 cfs Storm Frequency = 25-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 5,813 cuft Drainage Area = 0.35 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 6.0 min Total Rainfall = 6.72 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.842 cfs 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 Q (cfs) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Time (hrs)

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-D Hyd. No. 13 Hydrograph Type = NRCS Runoff Peak Flow = 2.760 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 8,904 cuft Drainage Area = 0.35 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 6.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.760 cfs 3 2 Q (cfs) 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Time (hrs)

PR-1B-UNDISTURBED WATERSHED

Project: Eagle Rock Avenue By: TEG Date: 10/21/2025 Location: West Orange, NJ Checked By: MJV Date Checked: 10/21/2025 Circle One: Present Developed Current Proposed Watershed PR-1B-U 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 Smooth Surfaces 1. Surface Description (NEH table 15-1) 2. Manning's Roughness Coeff., n (NEH table 15-1) 0.011 3. Flow Length, L (total L < 100 ft) ft 100 4. Two-year 24-hr rainfall, P2 in 3.46 5. Land Slope, s ft/ft 0.044 6. Compute Tt 0.007 (nL)0.8 hr 0.014 + + Tt = P20.5s0.4 Sheet Flow Sub-Total 0.014 hours Shallow Concentrated Flow Segment ID 2 3 4 Grassed Pavement Woodlands 7. Surface Description Waterways 8. Flow Length, L ft 369 32 44 9. Watercourse Slope, s ft/ft 0.035 0.170

369 32 44 9. Watercourse Slope, s ft/ft 0.035 0.170 0.290 10. Average Velocity, V (NEH table 15-3) ft/s 3.81 6.65 2.71 11. Compute Tt L hr 0.027 + 0.001 + 0.005 Tt = 3600 V Shallow Conc. Flow Sub-Total 0.033 hours Channel Flow Segment ID 5 6 7 12. Flow Length, L ft 358 25 117 13. Cross Sectional flow area, a ft2 0.69 0.61 0.61 14. Wetted Perimeter, Pw ft 3.58 2.00 2.00 15. Hydraulic Radius, r r = a / Pw ft 0.19 0.31 0.31 16. Channel Slope, s ft/ft 0.010 0.080 0.023 17. Manning's Roughness Coeff., n 0.035 0.013 0.013 18. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 1.42 14.69 7.89 19. Compute Tt L hr 0.070 + 0.000 + 0.004 Tt = 3600 V Channel Flow Sub-Total 0.075 hours Channel Flow

3600 V Channel Flow Sub-Total 0.075 hours Channel Flow Segment ID 8 9 20. Flow Length, L ft 15 51 21. Cross Sectional flow area, a ft2 0.61 0.61 22. Wetted Perimeter, Pw ft 2.00 2.00 23. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 24. Channel Slope, s ft/ft 0.055 0.021 25. Manning's Roughness Coeff., n 0.013 0.013 26. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 12.14 7.59 27. 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) = 0.124 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 7 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Proposed Tc Calcs\Current Proposed TCs\Current Proposed TC PR-1B-U Impervious v1.2

Project: Eagle Rock Avenue By: TEG Date: 10/21/2025 Location: West Orange, NJ Checked By: MJV Date Checked: 10/21/2025 Circle One: Present Developed Current Proposed Watershed PR-1B-U 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 Light Woods Light 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 67 23 4. Two-year 24-hr rainfall, P2 in 3.46 3.46 5. Land Slope, s ft/ft 0.068 0.505 6. Compute Tt 0.007 (nL)0.8 hr 0.153 + 0.029 + Tt = P20.5s0.4 Sheet Flow Sub-Total 0.182 hours Shallow Concentrated Flow Segment ID 3 Grassed 7. Surface Description Waterways 8. Flow Length, L ft 13 9. Watercourse Slope, s ft/ft 0.372 10. Average Velocity, V (NEH table 15-3)