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

b-Total Tt from prior steps) Total Tc (minutes) = 5 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Current 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 Current 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 3.46 3.46 5. Land Slope, s ft/ft 0.070 0.281 0.8 6. Compute Tt 0.007 (nL) hr 0.160 + 0.044 + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.203 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

Channel Flow Sub-Total 0.002 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.230 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 14 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Current Existing TC EX-1-D Pervious v1.2

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Open Space D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 0.932 cfs Storm Frequency = 2-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 3,786 cuft Drainage Area = 0.65 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.932 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 Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Woods D Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 0.967 cfs Storm Frequency = 2-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 3,966 cuft Drainage Area = 0.78 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.967 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 Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Impervious Hyd. No. 3 Hydrograph Type = NRCS Runoff Peak Flow = 0.304 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 1,087 cuft Drainage Area = 0.09 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.304 cfs 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 Q (cfs) 0.14 0.12 0.1 0.08 0.06 0.04 0.02 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 Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Hyd. No. 4 Hydrograph Type = Junction Peak Flow = 2.078 cfs Storm Frequency = 2-yr Time to Peak = 12.18 hrs Time Interval = 1 min Hydrograph Volume = 8,840 cuft Inflow Hydrographs = 1, 2, 3 Total Contrib. Area = 1.52 ac Qp = 2.078 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) EX-1-D Open Space D EX-1-D Woods D EX-1-D Impervious EX-1-D

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Open Space D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 1.871 cfs Storm Frequency = 10-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 7,614 cuft Drainage Area = 0.65 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.871 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 Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Woods D Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 2.057 cfs Storm Frequency = 10-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 8,335 cuft Drainage Area = 0.78 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.057 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)