PB 22 10 Altera 769 LLC Filed Application with Exhibits Final Site Plan Phase 2

Date: 6/14/2022 Project: Altera Development Project No: 2530-99-006 1904 Main Street, Lake Como, NJ 07719 Calculated By: SDP (732) 974-0198 Checked By: RJC Worksheet 3: Time of Concentration (T c ) Calculations Land Condition: Proposed Drainage Area: DA-1 • Sheet Flow : AB BC Woods, Light Woods, Light 1. Surface Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Underbrush Underbrush 2. Manning's Roughness Coefficient, n . . . . . . . . . . . . . . . . . . . . . . 0.4 0.4 3. Flow Length, L { total L ≤ 100 ft } . . . . . . . . . . . . . . . . . . . . . . . 50.0 ft 50.0 ft 4. Two-Year 24-hour Rainfall, p 2 for . . . Essex County .... 3.44 in 3.44 in 3.44 in 5. Land Slope, s (ft/ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.029 ft/ft 0.057 ft/ft 0.007 (n L ) 0.8 6. Travel Time, T t = 0.5 0.4 . . . . . . . . . . . . . . . . . . . . . . . 0.171 hr + 0.130 hr + 0.000 hr = 0.301 hr p2 s • Shallow Concentrated Flow :

0 hr + 0.000 hr = 0.301 hr p2 s • Shallow Concentrated Flow : CD DE EF 7. Surface Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unpaved Unpaved Unpaved 8. Flow Length, L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.0 ft 37.0 ft 20.0 ft 9. Watercourse Slope, s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.050 ft/ft 0.027 ft/ft 0.167 ft/ft 10. Average velocity, V { see Figure 3.1) . . . . . . . . . . . . . . . . . . . . . . 3.61 ft/s 2.65 ft/s 6.59 ft/s 11. Travel Time, T t = L . . . . . . . . . . . . . . . . . . . . . . . 0.002 hr + 0.004 hr + 0.001 hr = 0.007 hr 3600 V • Channel Flow : FG GH 12. Pipe Diameter, D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 in 18 in 13. Cross-Sectional Flow Area, A . . . . . . . . . . . . . . . . . . . . . . . . . 1.767 sf 1.767 sf 14. Wetted Perimeter, p w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 ft 4.7 ft 15. Hydraulic Radius, r = A / p w . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 ft 0.4 ft 16. Channel Slope, s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.020 ft/ft 0.020 ft/ft 17. Pipe Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HDPE HDPE 18. Manning's Roughness Coefficient, n . . . . . . . . . . . . . . . . . . . . . 0.010 0.010 2/3 1/2 1.49 r

ent, n . . . . . . . . . . . . . . . . . . . . . 0.010 0.010 2/3 1/2 1.49 r s 19. Velocity, V = ..................... 10.96 ft/s 10.96 ft/s n 20. Flow Length, L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134.0 89.0 21. Travel Time, T t = L . . . . . . . . . . . . . . . . . . . . . . . . 0.003 . . . . . hr ...+ . . . 0.002 . . . hr + 0.000 hr = 0.006 hr 3600 V 22. Watershed or subarea Time of Concentration, T c { add T t in steps 6, 11 and 21 } . . . . . . . . . . . . . . . . . . . . . . . . . 0.314 hr 18.8 min