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

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-2B-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. Design Flow Length, Ldes (Total Ldes < 100 ft) ft 100 4. Two-year 24-hr rainfall, P2 in 3.46 5. Land Slope, s ft/ft 0.073 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.012 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.012 hours Shallow Concentrated Flow Segment ID 2 Pavement 8. Surface Description 9. Flow Length, L ft 263 10. Watercourse Slope, s ft/ft 0.054 11. Average Velocity, V (NEH table 15-3) ft/s 4.73 12. Compute Tt L hr 0.015 + + Tt =

L hr 0.015 + + Tt = 3600 V Shallow Conc. Flow Sub-Total 0.015 hours Channel Flow Segment ID 13. Flow Length, L ft 14. Cross Sectional flow area, a ft2 15. Wetted Perimeter, Pw ft 16. Hydraulic Radius, r r = a / Pw ft 17. Channel Slope, s ft/ft 18. Manning's Roughness Coeff., n 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 20. Compute Tt L hr + + Tt = 3600 V Channel Flow Sub-Total 0.000 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.027 hours (Add Sub-Total Tt from prior steps) Software Limitations Require Minimum Tc = 2 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-2B-U 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 Current Proposed Watershed PR-2B-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 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 23 4. Two-year 24-hr rainfall, P2 in 3.46 5. Land Slope, s ft/ft 0.130 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.033 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.033 hours Shallow Concentrated Flow Segment ID 2 Pavement 8. Surface Description 9. Flow Length, L ft 231 10. Watercourse Slope, s ft/ft 0.048 11. Average Velocity, V (NEH table 15-3) ft/s 4.45 12. Compute Tt L hr 0.014 + +

ft/s 4.45 12. Compute Tt L hr 0.014 + + Tt = 3600 V Shallow Conc. Flow Sub-Total 0.014 hours Channel Flow Segment ID 13. Flow Length, L ft 14. Cross Sectional flow area, a ft2 15. Wetted Perimeter, Pw ft 16. Hydraulic Radius, r r = a / Pw ft 17. Channel Slope, s ft/ft 18. Manning's Roughness Coeff., n 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 20. Compute Tt L hr + + Tt = 3600 V Channel Flow Sub-Total 0.000 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.048 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\Current Proposed TCs\Current Proposed TC PR-2B-U Pervious v1.4

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2B-U Open Space C Hyd. No. 52 Hydrograph Type = NRCS Runoff Peak Flow = 0.015 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 41.3 cuft Drainage Area = 0.01 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 3.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.015 cfs 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 Q (cfs) 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 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-2B-U Impervious Hyd. No. 53 Hydrograph Type = NRCS Runoff Peak Flow = 0.101 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 329 cuft Drainage Area = 0.03 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 2.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.101 cfs 0.11 0.1 0.09 0.08 0.07 0.06 Q (cfs) 0.05 0.04 0.03 0.02 0.01 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-2B-U Hyd. No. 54 Hydrograph Type = Junction Peak Flow = 0.117 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 371 cuft Inflow Hydrographs = 52, 53 Total Contrib. Area = 0.04 ac Qp = 0.117 cfs 0.12 0.11 0.1 0.09 0.08 0.07 Q (cfs) 0.06 0.05 0.04 0.03 0.02 0.01 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-2B-U Open Space C PR-2B-U Impervious PR-2B-U

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2B-U Open Space C Hyd. No. 52 Hydrograph Type = NRCS Runoff Peak Flow = 0.033 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 90.9 cuft Drainage Area = 0.01 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 3.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.033 cfs 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 Q (cfs) 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 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-2B-U Impervious Hyd. No. 53 Hydrograph Type = NRCS Runoff Peak Flow = 0.159 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 525 cuft Drainage Area = 0.03 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 2.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.159 cfs 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 Q (cfs) 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 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-2B-U Hyd. No. 54 Hydrograph Type = Junction Peak Flow = 0.192 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 616 cuft Inflow Hydrographs = 52, 53 Total Contrib. Area = 0.04 ac Qp = 0.192 cfs 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 Q (cfs) 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 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-2B-U Open Space C PR-2B-U Impervious PR-2B-U