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Ditch D-D2 Ditch D-D2 is formed when the flow from ditch D-D1 and ditch D-E1 join below sediment pond C. From the intersection of the two flows the ditch becomes a V-Ditch that must be capable of handling the combined flow from the two ditches (1.79 + 14.62) = 16.41 The following information is generated from the use of the computer program Haestad Methods FlowMaster I version 3.43. The ditch side slopes are 1.5h:1v, Manning's n = 03. Ditch Flow Velocity Flow cfs Grade Depth fps 16.41 2% 1.5 5.1 16.41 10% 1.1 9.3 Construct Ditch D-2 two feet deep to allow for freeboard, The section with the 10% grade will require gunnite riprap or riprap and concrete lining for erosion protection. Culvert C-D1 Culvert C-D1 is located in ditch D-D2. The culvert must be 30" in diameter to handle the 16.41 cfs flow. Ditch D-D2 must be constructed at least 30"deep al the transition between the ditch and culvert Drainage Area E Drainage area E is the upland area located above the haul road that provides access to the gob pile. A berm will be constructed along the south side of the road to contain run-off to the site. A single ditch will be constructed on the north side of the road to handle the flow from drainage area E. The peak flow for this area is 1.79 cfs. Ditch D-E1 Drainage area E is the upland area located above the haul road that provides access to the gob pile. A berm will be constructed along the south side of the road to contain run-off to the site. A single ditch will be constructed on the north side of the road to Ditch Flaw Velocity Flow cfs Grade Depth fps 1.79 2% 0.65 2.90 Construct ditch D-E1 1.5 feet deep to allow for freeboard. Alternative sediment control features will be installed in the ditch to trap sediment before it leaves the site. Culvert C-E1 Culvert C-E1 was deleted from the design Jan. 1998. PR-07 EXH-8 -12 2/03