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-1A-U Hyd. No. 8 Hydrograph Type = Junction Peak Flow = 8.523 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 31,645 cuft Inflow Hydrographs = 5, 6, 7 Total Contrib. Area = 0.91 ac Qp = 8.523 cfs 9 8 7 6 5 Q (cfs) 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-1A-U Open Space C PR-1A-U Woods C PR-1A-U Imp PR-1A-U

= = PR-1A WATERSHED (COMBINED PROPOSED FLOW TO SSBB-1)

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A Total Hyd. No. 10 Hydrograph Type = Junction Peak Flow = 4.520 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 15,619 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 4.520 cfs 5 4 3 Q (cfs) 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-1A-D PR-1A-U PR-1A Total

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A Total Hyd. No. 10 Hydrograph Type = Junction Peak Flow = 7.705 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 27,101 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 7.705 cfs 8 7 6 5 Q (cfs) 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-1A-D PR-1A-U PR-1A Total

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A Total Hyd. No. 10 Hydrograph Type = Junction Peak Flow = 10.20 cfs Storm Frequency = 25-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 36,231 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 10.20 cfs 11 10 9 8 7 6 Q (cfs) 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-1A-D PR-1A-U PR-1A Total

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A Total Hyd. No. 10 Hydrograph Type = Junction Peak Flow = 15.13 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 54,595 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 15.13 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) PR-1A-D PR-1A-U PR-1A Total

PR-1B-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-1B-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 10 4. Two-year 24-hr rainfall, P2 in 4.08 5. Land Slope, s ft/ft 0.352 6. McCuen-Spiess Limit, Lmcs (max. 100 ft) Lmcs = (100 s0.5)/n ft 100 7. Compute Tt 0.007 (nLdes)0.8 hr 0.011 + + Tt = 0.5 0.4 P2 s Sheet Flow Sub-Total 0.011 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 397 25 117 14. Cross Sectional flow area, a ft2 0.69 0.61 0.61 15. Wetted Perimeter, Pw ft 3.58 2.00 2.00 16. Hydraulic Radius, r r = a / Pw ft 0.19 0.31 0.31 17. Channel Slope, s ft/ft 0.010 0.080 0.023 18. Manning's Roughness Coeff., n 0.035 0.013 0.013 19. Velocity, V V = (1.49 r2/3 s1/2 ) / n ft/s 1.42 14.69 7.89 20. Compute Tt L hr 0.078 + 0.000 + 0.004 Tt = 3600 V Channel Flow Sub-Total 0.082 hours Channel Flow Segment ID 5 6 21. Flow Length, L ft 15 51 22. Cross Sectional flow area, a ft2 0.61 0.61 23. Wetted Perimeter, Pw ft 2.00 2.00 24. Hydraulic Radius, r

ft2 0.61 0.61 23. Wetted Perimeter, Pw ft 2.00 2.00 24. Hydraulic Radius, r r = a / Pw ft 0.31 0.31 25. Channel Slope, s ft/ft 0.055 0.021 26. Manning's Roughness Coeff., n 0.013 0.013 2/3 1/2 27. Velocity, V V = (1.49 r s )/n ft/s 12.14 7.59 28. Compute Tt L hr 0.000 + 0.002 + Tt = 3600 V Channel Flow Sub-Total 0.002 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.095 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 6 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Proposed Tc Calcs\Future Proposed TC PR-1B-D Pervious v1.4