12 2026 02 12 Crestmont CC Stormwater Management Report

TOTAL ALLOWABLE FLOW TO POA-1

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 2 yr Allow Hyd. No. 19 Hydrograph Type = Junction Peak Flow = 15.52 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 59,528 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 15.52 cfs 17 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) EX-1-D 2 YR ALLOW EX-1-U POA-1 2 yr Allow

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 10 yr Allow Hyd. No. 20 Hydrograph Type = Junction Peak Flow = 27.85 cfs Storm Frequency = 10-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 108,913 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 27.85 cfs 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Q (cfs) 16 15 14 13 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) EX-1-D 10 YR ALLOW EX-1-U POA-1 10 yr Allow

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 100yr Allow Hyd. No. 21 Hydrograph Type = Junction Peak Flow = 56.05 cfs Storm Frequency = 100-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 223,454 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 56.05 cfs 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 Q (cfs) 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 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 100 YR ALLOW EX-1-U POA-1 100yr Allow

EX-2-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-2-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 100 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.056 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 4 Grassed 7. Surface Description Woodlands Pavement Waterways 8. Flow Length, L ft 23 140 155 9. Watercourse Slope, s ft/ft

ft 23 140 155 9. Watercourse Slope, s ft/ft 0.039 0.147 0.014 10. Average Velocity, V (NEH table 15-3) ft/s 3.19 1.93 2.39 11. Compute Tt L hr 0.002 + 0.020 + 0.018 Tt = 3600 V Shallow Conc. Flow Sub-Total 0.040 hours Channel Flow Segment ID 5 6 12. Flow Length, L ft 191 125 2 13. Cross Sectional flow area, a ft 0.61 0.61 14. Wetted Perimeter, Pw ft 1.96 1.96 15. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 16. Channel Slope, s ft/ft 0.014 0.009 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 6.14 5.13 19. Compute Tt L hr 0.009 + 0.007 + Tt = 3600 V Channel Flow Sub-Total 0.015 hours Watershed or subarea Tc or Tt

Channel Flow Sub-Total 0.015 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.067 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 4 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Future Existing TC EX-2-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-2-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 Woods Dense 1. Surface Description (NEH table 15-1) Underbrush 2. Manning's Roughness Coeff., n (NEH table 15-1) 0.40 3. Flow Length, L (total L < 100 ft) ft 100 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.066 0.8 6. Compute Tt 0.007 (nL) hr 0.197 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.197 hours Shallow Concentrated Flow Segment ID 2 7. Surface Description Woodlands 8. Flow Length, L ft 100 9. Watercourse Slope, s ft/ft 0.081 10. Average Velocity, V (NEH table 15-3) ft/s 1.43 11. Compute Tt L hr 0.019 + +

ft/s 1.43 11. Compute Tt L hr 0.019 + + Tt = 3600 V Shallow Conc. Flow Sub-Total 0.019 hours Channel Flow Segment ID 3 4 12. Flow Length, L ft 191 125 2 13. Cross Sectional flow area, a ft 0.61 0.61 14. Wetted Perimeter, Pw ft 1.96 1.96 15. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 16. Channel Slope, s ft/ft 0.013 0.009 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 6.14 5.13 19. Compute Tt L hr 0.009 + 0.007 + Tt = 3600 V Channel Flow Sub-Total 0.015 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.231 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 14 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site