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Response to DRMS Adequacy Review(2)—Cotter-9 Mine Reclamation Plan Amendment <br /> The offsite basin 10A is accurately represented by the original drawings. It is <br /> understood why DRMS could assume the need to reconfigure it with the existence of <br /> the channels indicated by the blue dashed lines on the drawings. These channels are <br /> of no significance, if existing at all, and were possibly part of an initial idea to divert <br /> flows away from the stockpile. They do not show up on the topo survey and are not <br /> visible in the site photos. The channel labeled Ill", Proposed Diversion Channel, on <br /> sheet 3 of 10 is actually the natural channel formed by the installation of the waste <br /> rock pile next to the adjacent hillside. The stockpiling of this material formed a berm <br /> which will intercept a portion of the flows from the hillside to the north and send them <br /> west to the large natural open drain. Some flows from the north will enter the waste <br /> rock area(basin 30B) and some will flow to the shop/dry building site. After <br /> installation of the proposed Diversion Berm "2" (sheet 3 of 10 on the last set of <br /> drawings)some flows from the north will be diverted around the shop area to be <br /> discharged overland offsite as described in earlier portions of the response to this <br /> comment. We believe the current representation of the basin boundaries in the revised <br /> drawings provided for this review accurately reflect the runoff patterns for the site. <br /> These areas were used in the hydrologic calculations for the project. A new analysis is <br /> included however for the additional section requested where this channel drops into <br /> the large natural drain along the west side of the site. This can be seen in the <br /> Attachment 2. <br /> 13. Sheet 3 of 10. New and modified features: <br /> a. There are two diversion channels upgradient of proposed retention pond that are <br /> not labeled or analyzed. Please see Figure 3 below and either provide the <br /> 9 <br />