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z.s-2 Runoff from watershed B, the 0.1 sgmi, drainage area south of the • bench area, will be conveyed around the disturbed area in a ditch constructed to convey the volume of flow safely. The flow will be directed to a ditch on the north side of the haul road using a 21 inch diameter culvert, see Figure 2.2-14. The ditch shall then convey the flow west beyond the sedimentation reservoir. DISTURHBD FLUW - MINB BBNCH ARBA The total area to be disturbed by the mine bench is approximately six acres. This bench will consist of three main features: the cut slope to the south, the mine bench area, and the permanent diversions to the northeast. Flow from direct precipitation over the cut slope and mine facilities area will be intercepted by collector ditches along the perimeter of the area as shown in Figures 2.2-14 and 2.3-1. These ditches are designed to carry the runoff from a 10 year 24 hour precipitation event and will direct the flow to a culvert inlet on the north corner of the bench. The mine bench will slope from 2~ to 3ro toward the ditches. The culvert will be buried on the outslope of the embankment to direct runoff to the sediment pond. Runoff from the outslope will be directed to the same pond. Pond design is discussed in Section 2.3.4. UNDISTURBBD FLOW - HAUL ROAD Runoff from the undisturbed areas of watersheds C, D, H, F, X, and the Munger Creek drainage basin will be passed through culverts • under the haul road as shown in Figure 2.3-4. Flow rates and culvert sizes are listed in Table 4.5-11. Headwall protection for the culverts will be provided by a flared end section at the inlet. UNDISTURBBD FLOW - WASTfi ROCK DISPOSAL ARfiA The flow from approximately 18 acres of drainage area X will be affected by the waste rock disposal site. This area will be drained by two channels designed to carry peak flows from a 10 year 24 hour precipitation event. The diversions are shown on Figure 2.2-6, and runoffs for each are given in Table 4.5-11. Drainage from the eastern portion will be diverted to an existing drainage where it will flow through a culvert under the road into the receiving drainage. The remaining flow, from approximately 6 acres, will be diverted to the west where it will enter natural drainages. DISTURBHD FLOW - WASTB ROCK DISPOSAL ARBA Runoff from disturbed areas of the waste rock disposal area will be limited to direct precipitation. Total area of the site is about 2.6 acres. Interceptor channels are designed to contain and direct this flow to the sediment pond as shown in Figures 2.2-6 and 2.2-7. This pond is discussed ir. Section 2.3-4. • Mli R IV - off, ~~~ ~~?:;