Revised Stormwater Management Report

Date: Project: Project No: 40 Miller Drive; Boonton, NJ 07005 (973) 975-0703 6/11/2024 WEH - Calculated By: ASM Checked By: PWA Conduit Outlet Protection Calculations Rip Rap Pad # B-1 Design Parameters: Design Storm Flow for 25 Year, Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vertical Dimension of Outlet Pipe, D o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizontal Dimension of Outlet Pipe, W o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tailwater Depth, TW 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.73 cfs 15 in 15 in 0.25 ft Apron Dimension Calculations: Unit Dicharge, q = Q/D o = 0.58 cfs per foot  Case I: TW < 1/2 D o 1.8q + D o 1/2 Width, W 1 = 3W o = 3.75 ft Width, W 2 = 3W o + L a = Apron Length, L a = 7D o = 13.44 ft 9.69 ft or La = 10 ft or or W1 = W2 = 4 ft 14 ft  Case II: TW ≥ 1/2 D o Apron Length, L a = 3q D o 1/2 Width, W 1 = 3W o = Width, W 2 = 3W o + 0.4L a = = La = W1 = W2 = Rip Rap Stone Size Calculations: 1.33 Median Stone, d 50 = 0.02q d 50 = 0.47 in = 6 in TW Notes: 1. Where there is a well-defined channel downstream of the apron, the bottom width of the apron shall be at least equal to the bottom width of the channel and the structural lining shall extend at least one foot above the tailwater elevation, but no lower than two-thirds of the vertical conduit dimension above the conduit invert. 2. The side slopes shall be 2:1 or flatter. 3. The bottom grade shall be 0.0% (level). 4. There shall be no overfall at the end of the apron or at the end of the culvert. 5. Fifty (50) percent by weight of the rip-rap mixture shall be smaller than the median size stone designated as d 50. The largest stone size in the mixture shall be 1.5 times the d50 size. The rip-rap shall be reasonably well graded. 6. The thickness of the rip-rap apron may be two (2) times the median stone diameter provided that the apron is constructed on a bedding of four (4) inches of 3/4 inch clean stone on approved filter fabric material. 7. Rip-rap and filter fabric shall meet the standards of the governing Soil Conservation District as well as the requirements of the local municipality. 8. No

stone on approved filter fabric material. 7. Rip-rap and filter fabric shall meet the standards of the governing Soil Conservation District as well as the requirements of the local municipality. 8. No bends or curves at the intersection of the conduit and apron will be permitted. Footnote: 1. Tailwater depth shall be the 2-year storm if discharging into a detention basin. For areas where tailwater cannot be computed, use TW = 0.2D o . 2. For multiple pipes, increase rip-rap sizes by 25% when pipe spacing is greater than or equal to 1/4W o .