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

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B (Swale) Hyd. No. 21 Hydrograph Type = Junction Peak Flow = 14.48 cfs Storm Frequency = 25-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 55,845 cuft Inflow Hydrographs = 13 Total Contrib. Area = 0.35 ac Qp = 14.48 cfs 16 15 14 13 12 11 10 9 Q (cfs) 8 7 6 5 4 3 2 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-D PR-1B-U PR-1B (Swale)

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B (Swale) Hyd. No. 21 Hydrograph Type = Junction Peak Flow = 21.76 cfs Storm Frequency = 100-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 84,859 cuft Inflow Hydrographs = 13 Total Contrib. Area = 0.35 ac Qp = 21.76 cfs 25 24 23 22 21 20 19 18 17 16 15 14 13 Q (cfs) 12 11 10 9 8 7 6 5 4 3 2 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-D PR-1B-U PR-1B (Swale)

PR-1C-DISTURBED 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 Future Proposed Watershed PR-1C-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 Smooth Surfaces 1. Surface Description (NEH table 15-1) 2. Manning's Roughness Coeff., n (NEH table 15-1) 0.011 3. Design Flow Length, Ldes (Total Ldes < 100 ft) ft 79 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.010 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.020 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.020 hours Shallow Concentrated Flow Segment ID 8. Surface Description 9. Flow Length, L ft 10. Watercourse Slope, s ft/ft 11. Average Velocity, V (NEH table 15-3) ft/s 12. Compute Tt L hr + + Tt = 3600 V

+ Tt = 3600 V Shallow Conc. Flow Sub-Total 0.000 hours Channel Flow Segment ID 2 3 4 13. Flow Length, L ft 69 282 54 14. Cross Sectional flow area, a ft2 0.61 0.61 0.88 15. Wetted Perimeter, Pw ft 2.00 2.00 2.40 16. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 0.37 17. Channel Slope, s ft/ft 0.005 0.023 0.020 18. Manning's Roughness Coeff., n 0.013 0.013 0.013 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 3.67 7.95 8.30 20. Compute Tt L hr 0.005 + 0.010 + 0.002 Tt = 3600 V Channel Flow Sub-Total 0.017 hours Channel Flow Segment ID 5 6 7 21. Flow Length, L ft 17 51 67 22. Cross Sectional flow area, a ft2 0.88 0.88 0.88 23. Wetted Perimeter, Pw

rea, a ft2 0.88 0.88 0.88 23. Wetted Perimeter, Pw ft 2.40 2.40 2.40 24. Hydraulic Radius, r r = a / Pw ft 0.37 0.37 0.37 25. Channel Slope, s ft/ft 0.049 0.021 0.042 26. Manning's Roughness Coeff., n 2/3 1/2 27. Velocity, V V = (1.49 r s )/n ft/s 28. Compute Tt L hr + + Tt = 3600 V Channel Flow Sub-Total 0.000 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.036 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 2 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Proposed Tc Calcs\Future Proposed TC PR-1C-D Impervious v1.4

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 Future Proposed Watershed PR-1C-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 Dense Grasses 1. Surface Description (NEH table 15-1) 2. Manning's Roughness Coeff., n (NEH table 15-1) 0.24 3. Design Flow Length, Ldes (Total Ldes < 100 ft) ft 54 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.212 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.050 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.050 hours Shallow Concentrated Flow Segment ID 8. Surface Description 9. Flow Length, L ft 10. Watercourse Slope, s ft/ft 11. Average Velocity, V (NEH table 15-3) ft/s 12. Compute Tt L hr + + Tt = 3600 V

+ Tt = 3600 V Shallow Conc. Flow Sub-Total 0.000 hours Channel Flow Segment ID 2 3 4 13. Flow Length, L ft 17 51 67 14. Cross Sectional flow area, a ft2 0.88 0.88 0.88 15. Wetted Perimeter, Pw ft 2.40 2.40 2.40 16. Hydraulic Radius, r r = a / Pw ft 0.37 0.37 0.37 17. Channel Slope, s ft/ft 0.049 0.021 0.042 18. Manning's Roughness Coeff., n 0.013 0.013 0.013 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 13.05 8.54 11.98 20. Compute Tt L hr 0.000 + 0.002 + 0.002 Tt = 3600 V Channel Flow Sub-Total 0.004 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.054 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 3 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Proposed Tc Calcs\Future Proposed TC PR-1C-D Pervious

\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Proposed Tc Calcs\Future Proposed TC PR-1C-D Pervious v1.4

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1C-D Open Space D Hyd. No. 24 Hydrograph Type = NRCS Runoff Peak Flow = 0.842 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 2,296 cuft Drainage Area = 0.32 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 3.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.842 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)