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Drainage ditches will be placed at the toe of all cut slopes formed by the construction of haul roads. <br />• Water will be intercepted before reaching a large fill and drained safely away in accordance with the <br />requirements of 4.03.1. Water from a fill will be released below the fill through conduits or in <br />adequately lined channels and will not be discharged onto the fill. <br />When haul road drainage ditches discharge onto open terrain, a number of measures will be taken to <br />protect the terrain from erosion. SCC will utilize measures as revegetation, straw dikes, and riprap to <br />protect the terrain from erosion caused by discharge from haul road ditches. When the road ditch <br />discharges onto an area disturbed by haul road construction, the terrain will be revegetated to control <br />runoff and erosion. In an area where revegetation would not be sufficient to control erosion, the area <br />will 6e riprapped. Temporary measures to reduce erosion (straw dikes, containment ditches, silt fence, <br />etc) will be employed while the area is undergoing revegetation. <br />SCC typically constructs ditches on the inside of roadway cuts and safety berms for drainage. A <br />typical V-ditch section would be a minimum of one foot deep with side slopes 2:1 or flatter. As most <br />road cuts are into resistant bedrock-type material, ditches normally do not require lining. Culverts will <br />be designed and installed to minimize the runoff volume conveyed in each ditch. Culverts and ditches <br />will typically be designed using SEDCAD+ or SEDCAD 4 to predict the peak runoff and Manning's <br />equation to determine the peak velocity and flow depth Isee Attachment 13-1, General Hydrology <br />• Design Methodsl. Attachment 13-7, Haul Road Ditch Designs, contains the design calculations for <br />Haul Road A and B ditches, while Exhibit 13-9. Typical Haul Road Details, shows the ditch details. <br />Attachment 13-12, Drainage and Sediment Control Plan, contains the details and designs for the <br />proposed haul roads. <br />Drainage from haul roads within the areas disturbed by mining and reclamation activities Isee Exhibit <br />13-2, Surface Water Control Plan, and Attachment 13-12, Drainage and Sediment Control Plan) will be <br />constructed to meet the requirements of 4.05.2 and such haul roads will at a minimum be constructed <br />and maintained to minimize erosion of the disturbed area. Erosion control measures to be used singly <br />or in combination include but are not limited to: <br />a. Stabilizing all exposed surface areas to promote a reduction in the rate and volume of <br />runoff; <br />b. Using straw dikes, riprap, check dams, berms, geotextile materials, mulches, vegetation <br />sediment filters, contour furrows or other measures that reduce overland flow velocity, <br />reduce runoff volume, or trap sediment; or <br />• <br />17 Revised 2/99 <br />