Laserfiche WebLink
3 <br />SUN COAL COMPANY <br />MEADOWS N0. 1 <br />IMPOUNDMENT CERTIFICATION <br />"As-Built" Design <br />Impoundment No. 1 (Upper Pond) <br />Ten year 24 hour storm event 1.6 inches <br />Twenty-five year 24 hour storm event 2.0 inches <br />One hundred year 24 hour storm event 2.3 inches <br />Ten year 24 hour runoff 11.0 cfs-Total flow 0.80 acre feet <br />Twenty Pive year 24 hour runoff 20.9 cfs-Total flow 1.52 acre feet <br />One hundred year 29 hour runoff 29.7 cfs-Total flow 2.35 acre feet <br />Soil Conservation Service Curve Number 75 <br />Drainage Area 48.2 acres <br />Vegetative Type-Grassland <br />Principal Spillway <br />Drop Structure 36 inch-Capacity 28 cfs <br />Drop Structure Embankment Discharge Pipe= 18 inch CMP <br />Capacity with Head approximately 22 cfs <br />Emergency Spillway Design <br />Trapezoidal <br />Spillway Depth 2 feet <br />Spillway Width 10 feet <br />Spillway Sideslopes 2:1 <br />Riprap D-50=6 inches <br />Riprap Channel Length 20 feet <br />Spillway Flow Characteristics 100 year storm <br />Peak Flow 30 cfs <br />Depth of Plow .790 feet <br />Flow Velocity 3.3 fps slope W 1 percent <br />Embankment Height 9 feet <br />Embankment Width 15 feet <br />Embankment Length 280 <br />Impoundment Storage Capacity 1.1 acre feet <br />Impoundment Sediment Storage Capacity See Figure 56 <br />Topsoil Depth 6 inches <br />Vegetative Type Grass <br />