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

TOTAL PROPOSED FLOW TO POA-1

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 Hyd. No. 32 Hydrograph Type = Junction Peak Flow = 14.07 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 60,072 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 14.07 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 26 27 Time (hrs) PR-1A Routing PR-1B (Swale) PR-1C-D PR-1C-U POA-1

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 Hyd. No. 32 Hydrograph Type = Junction Peak Flow = 24.77 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 106,676 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 24.77 cfs 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Q (cfs) 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 26 27 Time (hrs) PR-1A Routing PR-1B (Swale) PR-1C-D PR-1C-U POA-1

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 Hyd. No. 32 Hydrograph Type = Junction Peak Flow = 33.09 cfs Storm Frequency = 25-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 143,827 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 33.09 cfs 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 Q (cfs) 19 18 17 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 26 27 Time (hrs) PR-1A Routing PR-1B (Swale) PR-1C-D PR-1C-U POA-1

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-1 Hyd. No. 32 Hydrograph Type = Junction Peak Flow = 53.61 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 218,689 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 53.61 cfs 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 Q (cfs) 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 26 Time (hrs) PR-1A Routing PR-1B (Swale) PR-1C-D PR-1C-U POA-1

PR-2A-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-2A-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 90 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.019 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.017 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.017 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 13. Flow Length, L ft 167 34 14. Cross Sectional flow area, a ft2 0.61 0.61 15. Wetted Perimeter, Pw ft 2.00 2.00 16. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 17. Channel Slope, s ft/ft 0.010 0.050 18. Manning's Roughness Coeff., n 0.012 0.012 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 5.63 12.58 20. Compute Tt L hr 0.008 + 0.001 + Tt = 3600 V Channel Flow Sub-Total 0.009 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.026 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\Future Proposed TC PR-2A-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-2A-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 62 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.066 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.089 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.089 hours Shallow Concentrated Flow Segment ID 2 Grassed 8. Surface Description Waterways 9. Flow Length, L ft 8 10. Watercourse Slope, s ft/ft 0.120 11. Average Velocity, V (NEH table 15-3) ft/s 5.59 12. Compute Tt L hr 0.000

verage Velocity, V (NEH table 15-3) ft/s 5.59 12. Compute Tt L hr 0.000 + + Tt = 3600 V Shallow Conc. Flow Sub-Total 0.000 hours Channel Flow Segment ID 3 4 5 13. Flow Length, L ft 49 34 18 14. Cross Sectional flow area, a ft2 0.61 0.61 0.61 15. Wetted Perimeter, Pw ft 2.00 2.00 2.00 16. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 0.31 17. Channel Slope, s ft/ft 0.071 0.005 0.035 18. Manning's Roughness Coeff., n 0.012 0.012 0.012 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 15.01 3.98 10.56 20. Compute Tt L hr 0.001 + 0.002 + 0.000 Tt = 3600 V Channel Flow Sub-Total 0.004 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.093 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) =