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SPECIFY THAT THE AS-BUILT CHAh;NEL MEETS THE MINIhiUM REQUIREMENTS OF THE <br />APPROVED DESIGN INCLUDING DIMEf1SI0NS, GRADES, RIPRAP AND BED THICKNESS AND <br />SORTING. <br />RESPONSE: <br />As discussed, CYCC has had new maps made for the Eckman Park area. <br />This was done after it was found that the mapping, which was used in <br />the permit revision, contained some discrepancies. The new maps <br />demonstrate that the drainage gradients have been reduced. The <br />Postmining Topography Map (Permit Revision 86-2-2 (Map 48A)), was <br />redrawn using this latest mapping. <br />Profiles drawn for drainage 9/10-2 (51E) show that there is little <br />difference, if any, between the premining gradient and the proposed <br />gradient. Also, as per Map 86-2-2 (Map 48A) the drainage, where it <br />intercepts the active pit, will be routed to the west. This will <br />• decrease the amount of flow through this drainage. CYCC, as proposed <br />in the permit revision, will riprap this drainage to further stabilize <br />this drainage. Drainage 9/10-3 does not appear on the new mapping. <br />In reference to drainages 31-1 and 31-2, Table 3-2 of Appendix II, <br />shows that riprap would be required if the drainage is reconstructed <br />per the approved plan. Therefore, it is recommended that the proposed <br />work for. these drainages be approved. The proposed riprap should <br />provide for a stable drainage and complement the proposed postmining <br />land use. <br />In reference to the remainder of the drainages, the new map indicates a <br />reduction in the drainage gradient. The slopes for these are as <br />follows: <br />Existing Topographic hlap <br />Location 1985 I4apping <br />. 7-1 330 <br />51 25°~ <br />New Topographic Map <br />1986 Mapping <br />23.8,E <br />13.9`,b <br />