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

Based on "Standards for Soil Erosion and Sediment Control in New Jersey," dated 2014 TABLE 12-1 ALLOWABLE VELOCITIES FOR VARIOUS SOILS SOIL TEXTURE ALLOWABLE VELOCITY (ft./sec.) 1. Sand 1.8 2. Sandy Loam 2.5 3. Silt loam (also high lime clay), loam 3.0 4. Sandy clay loam 3.5 5. Clay loam 4.0 6. Clay, fine gravel, gradded loam to gravel 5.0 7. Cobbles 5.5 8. Shale (non-weathered) 6.0 Soil type where outfall is located = 2 (Note: Select number designating soil texture above) allowable velocity = 2.5 ft/sec v (velocity) = 4.83 ft/sec Rip Rap Apron required? 1 (1 = yes, 0 = no) Given: Do (max inside height) = 1.25 feet Wo (max inside width) = 1.25 feet Q (discharge) = 5.2 cfs (25 year storm) *q (unit discharge, = Q/Wo) = 4.2 cfs / foot ** Tw (tail water) = 1.8 feet * for the conduit design storm or the 25 year storm, whichever is greater ** for areas where Tw cannot be computed, use Tw = 0.2 Do. For discharge into detention basins, Tw shall equal the 2 year storm elevation in the basin. Riprap Apron Dimensions I. The length of the apron, L (in feet), shall be determined from the formula: q La = (1.8 1/ 2 ) + 7Do Tw < ½ Do La = 0 feet Do q La = 3 1 Tw > ½ Do La = 11 feet Do2 II. Where there is no well-defined channel immediately downstream of the apron, the width, W, of the

Do La = 11 feet Do2 II. Where there is no well-defined channel immediately downstream of the apron, the width, W, of the outlet end of the apron shall be as follows: For tailwater elevation greater than or equal to the elevation of the center of the pipe, W = 3Wo + 0.4 La W= 8 feet For tailwater elevation less than the elevation of the center of the pipe, W = 3W o + L a W= 0 feet Where La is the length of the apron determined from the formula and Wo is the culvert width. Project: HW1-3 RIP RAP APRON DESIGN 300 Kimball Drive Parsippany, NJ WEST ORANGE NEW JERSEY P: 973.560.4900 F: 973.560.4901 Project No. Date: By: Ckd: Sheet. No. NJ Certificate of Authorization No: 24GA27996400 101049802 10/17/2025 TEG MJV 1 of 2

Riprap Median Stone Diameter The median stone diameter, D50, in feet, shall be determined from the formula: 0 . 016 1 . 33 Where q = Q/Do D 50 = q For Horizontal Apron: T w D50 = 0.06 ft OR D50 = 0.7 inches Use Min. D50 = 3.0 inches Note: For discharge into Detention Basins, analyze the hydraulic characteristics of the basin for the design storm to determine the combination of conduit discharge and tailwater that results in the largest required D50 stone size. Riprap Lining Thickness The thickness of riprap lining shall meet at least one of the following criteria: 1. A thickness of at least three times the D50 size if a filter layer is not used. t= 2.2 inches 2. A thickness of at least two times the D50 size if a filter layer is used. t= 1.4 inches *Minimum required thickness is 6 inches. Use Min. t = 6.0 inches For tailwater elevation greater than or equal to the elevation of the center of the pipe La = 11 W= 8 For tailwater elevation less than the elevation of the center of the pipe La = 0 W= 0 Project: HW1-3 RIP RAP APRON DESIGN 300 Kimball

HW1-3 RIP RAP APRON DESIGN 300 Kimball Drive Parsippany, NJ WEST ORANGE NEW JERSEY P: 973.560.4900 F: 973.560.4901 Project No. Date: By: Ckd: Sheet. No. NJ Certificate of Authorization No: 24GA27996400 101049802 10/17/2025 TEG MJV 2 of 2

COUNTY CONVEYANCE SYSTEM DESIGN

= = SUPPORTING BASIN OUTFLOW HYDROGRAPH REPORTS

SSBB-1

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-22-2025 PR-1A Routing Hyd. No. 11 Hydrograph Type = Pond Route Peak Flow = 2.246 cfs Storm Frequency = 10-yr Time to Peak = 12.28 hrs Time Interval = 1 min Hydrograph Volume = 19,163 cuft Inflow Hydrograph = 10 - PR-1A Total Max. Elevation = 535.71 ft Pond Name = SSBB-1 Max. Storage = 8,419 cuft Pond Routing by Storage Indication Method Center of mass detention time = 1.63 hrs Hydrograph Discharge Table Time Outflow Time Outflow Time Outflow Time Outflow Time Outflow (hrs) (cfs) (hrs) (cfs) (hrs) (cfs) (hrs) (cfs) (hrs) (cfs) 10.53 0.026 10.95 0.136 11.37 0.344 11.78 0.703 12.20 2.136 10.55 0.029 10.97 0.144 11.38 0.355 11.80 0.725 12.22 2.185 10.57 0.033 10.98 0.151 11.40 0.366 11.82 0.747 12.23 2.218 10.58 0.037 11.00 0.158 11.42 0.377 11.83 0.774 12.25 2.235 10.60 0.040 11.02 0.166 11.43 0.388 11.85 0.794 12.27 2.244 10.62 0.044 11.03 0.173 11.45 0.399 11.87 0.816 12.28 2.246 10.63

0.794 12.27 2.244 10.62 0.044 11.03 0.173 11.45 0.399 11.87 0.816 12.28 2.246 10.63 0.048 11.05 0.181 11.47 0.410 11.88 0.839 12.30 2.245 10.65 0.052 11.07 0.188 11.48 0.421 11.90 0.862 12.32 2.238 10.67 0.055 11.08 0.196 11.50 0.432 11.92 0.887 12.33 2.226 10.68 0.059 11.10 0.204 11.52 0.443 11.93 0.918 12.35 2.207 10.70 0.063 11.12 0.211 11.53 0.456 11.95 0.953 12.37 2.182 10.72 0.067 11.13 0.219 11.55 0.471 11.97 0.990 12.38 2.154 10.73 0.071 11.15 0.227 11.57 0.487 11.98 1.029 12.40 2.125 10.75 0.075 11.17 0.235 11.58 0.503 12.00 1.067 12.42 2.096 10.77 0.079 11.18 0.243 11.60 0.519 12.02 1.106 12.43 2.066 10.78 0.083 11.20 0.251 11.62 0.536 12.03 1.153 12.45 2.036 10.80 0.087 11.22 0.259 11.63 0.552 12.05 1.206 12.47 2.005 10.82 0.091 11.23 0.267 11.65 0.567 12.07 1.263 12.48 1.976 10.83 0.095 11.25 0.276 11.67 0.581 12.08 1.371 12.50 1.947 10.85 0.099 11.27 0.284 11.68 0.596 12.10 1.498 12.52 1.918 10.87 0.103 11.28 0.292 11.70 0.610 12.12 1.670 12.53 1.887 10.88 0.107 11.30 0.301 11.72 0.624 12.13 1.807

0.292 11.70 0.610 12.12 1.670 12.53 1.887 10.88 0.107 11.30 0.301 11.72 0.624 12.13 1.807 12.55 1.854 10.90 0.114 11.32 0.311 11.73 0.641 12.15 1.921 12.57 1.820 10.92 0.121 11.33 0.321 11.75 0.661 12.17 2.007 12.58 1.792 10.93 0.129 11.35 0.333 11.77 0.682 12.18 2.076 12.60 1.764 Printed values > 1% of Qpeak. nth-point print interval = 1