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Materials from both stockpiles will be used for mine reclamation. Basin C is 9.23 acres in <br /> area with shrubs, pinyon, and juniper trees <br /> The access road from Temple Canyon Road will be located east of the laydown and <br /> stockpile areas. Culverts are shown on the design drawings at strategic locations to direct <br /> offsite surface water between these areas and into Channel C: Onsite Stormwater Diversion <br /> Channel. Water in Basin C will flow downward towards the west into Channel C and then <br /> into the detention-sedimentation pond north of the stockpiles. A 24-inch culvert will release <br /> water at historical rates for the entire project by reducing the historical flows in Basin C by <br /> the increase in flow at Basins B, C and F. <br /> Historical and post-development runoff flows for this basin are presented in Tables 2 and <br /> 3 above. <br /> Basin D— East Offsite Stormwater <br /> Basin D has been divided into 4 subbasins(D I, D2, D3, and 134)to determine culvert sizes <br /> and offsite flow onto the project from the east. Each subbasin was delineated based on <br /> culvert locations and site topography. Basin D extends from the primary access road <br /> upward to the ridge tops to the east. <br /> Basin D is 23.5 acres with a 24-hour — 10 year, and 100-year discharge of 61.69 cfs and <br /> 84.20 cfs respectively. No development is proposed in Basin D and no changes to water <br /> discharge rates are expected due to the proposed mine. <br /> Water will flow downward to the access road, through 24 or 30-inch culverts, down to <br /> Channel C and then into the detention-sedimentation pond where it'll be released at <br /> historical flow rates for the project. <br /> Basin E—Offsite Natural Drainage <br /> Offsite flows were determined for the natural drainage as it enters the project. <br /> Basin E is 207.03 acres with a 24-hour— 10 year, and 100-year discharge of 81.29 cfs and <br /> 231.6 cfs respectively. <br /> Water in this basin will enter the site at an existing 84-inch diameter corrugated metal pipe <br /> (CMP) culvert. The natural drainage is between the operations and stockpile areas of the <br /> project, leaves the project, crosses Temple Canyon Road, and flows through undeveloped <br /> areas until it discharges into Grape Creek. <br /> Vegetation in Basin E is shrubs, pinyon and juniper trees, and native grasses. <br /> No development is proposed in Basin E and no changes to water discharge rates are <br /> expected due to the proposed mine. <br /> Basin F—Access Road Improvements <br /> N <br /> To determine the difference in runoff from access road improvements, pre and post o <br /> development runoff rates were determined. The access road is currently a 2-track dirt road Z <br /> and will be improved to a 40-foot-wide gravel surfaced road. <br />