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Table 3-3. Hydrologic Inputs <br /> Drainage Area Proposed Area Flow Path Length Percent (%) <br /> (Acres) (Miles) Impervious <br /> 02A 15 0.405 25 <br /> 02B 55 0.327 50 <br /> 03 87 1.401 50 <br /> Table 3-4 presents a summary of the 5-year and 100-year peak flow calculations for each sub- <br /> drainage basin impacted by the drainage design. <br /> Table 34. Hydrology Summary Table for Basins Used in Diversion Channel Design <br /> Drainage Area Area(acres) 5-year Peak Flow Rate 100-year Peak <br /> (cfs) Flow Rate (cfs) <br /> 02A 15 6.6 25.4 <br /> 02B 55 67.3 201.8 <br /> 03 87 48.9 151.4 <br /> Based on these calculations, the diversion channel design flow is 25.4 cubic feet per second (cfs). <br /> Detailed calculations and the proposed drainage conditions to support these results are included in <br /> Appendix E. <br /> 3.3 Diversion Channel Design <br /> The design focused on a diversion channel that will collect and convey water from the <br /> reclaimed south quarry highwall above elevation 7110 ft., down a steep chute, to the existing <br /> south quarry drainage area. The diversion channel design was completed using Manning's <br /> equation for open channel flow for the design criteria presented in Section 2.3. <br /> The diversion channel configuration along the south quarry highwall bench is limited by the width of <br /> the inactive quarry bench. In concert with the geotechnical analysis summarized in Section 3.4, the <br /> channel is proposed to have a bottom width of 2 feet, a constructed depth of 3 feet, side slopes of <br /> 21-1:1 V, and have a geotextile anchor trench along the reclaimed highwall with clay content material <br /> to mitigate potential infiltration of flows entering the channel. The configuration of the diversion <br /> channel chute is identical to the bench diversion channel configuration with the exception of the <br /> bottom width increase to 3 feet to ensure that a commonly available D50 = 12 inch riprap material is <br /> stable. For both channel features, the channel geocomposite liner is proposed to be Canal3® by <br /> Huesker because it allows for an impermeable layer that is also geotechnically stable. The key <br /> design parameters are summarized in Table 3-5. <br /> Refer to Appendix F for detailed hydraulic calculations and Appendix H for the design drawings <br /> and specifications. <br /> 1670 Broadway,Suite 3400,Denver,CO 80202-4824 hdrinc.com <br /> (303)764-1520 <br />