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Rule 4.05.4 - Stream Channel Diversions and Stream Channel Reconstruction <br />4. The narrative on revised page Exh.7-14R-3 discusses the use and design of temporary <br />ditches to divert runoff from spoil and reclaimed areas to the unreclaimed East Pit. These <br />temporary ditches result in areas that are excluded from producing runoff in the <br />SEDCAD modeling for the Prospect Pond. The text narrative references Figure Exh.7- <br />14R-7 and states that the ditches are "short term in nature and will be removed as <br />reclamation progresses." Figure Exh.7-14R-7 shows one of the ditches extending a <br />significant distance northeast into previously reclaimed areas. Please explain in more <br />detail in the narrative on revised page Exh.7-14R-3 how and when these ditches will <br />be constructed and used and when each ditch will be removed or reclaimed. <br />Currently approved permit page Exh.7-14D2 (revised 25 July 2006, TR-63) shows the <br />approved design information for the Final East Pit Ditch and the Prospect Ditch <br />permanent channels. Proposed SEDCAD design runs for the 10-year, 24-hour storm <br />event for the Prospect Pond result in new design information for the Final East Pit Ditch <br />and Prospect Ditch that would appear to supersede the currently approved information on <br />page Exh.7-14D2. Please review the designs for the Final East Pit Ditch and the <br />Prospect Ditch and submit new permanent channel design information that is <br />consistent with the SEDCAD modeling submitted with Technical Revision 87 for <br />these two ditches. <br />6. Based on the backfilling and grading schedule (Map 29), Colowyo will be constructing <br />portions of their permanent, post-mining drainage channels over several reclamation <br />seasons. In order to ensure that the yearly channel construction has been completed as <br />designed, the Division has requested that Colowyo provide a yearly as-built certification <br />of all ditch segments constructed during a reclamation season. The Division has <br />requested that this information be included in the Annual Reclamation Report. Please <br />revise the text in Permit Section 4.05.4 and in the introductory text to Exhibit 7, <br />Item 14 committing to providing the Division with yearly as-built certifications for <br />all post-mining drainage channels constructed in a reclamation season in the Annual <br />Reclamation Report for that year's reclamation. The as-built certification will, at a <br />minimum, detail the construction of each channel segment (Width, depth, riprap <br />D50, etc.) and, provide a map or drawing of each channel segment, reference the <br />exhibit that was used to determine design requirements for the channel segment and <br />provide representative pictures of each channel segment constructed. <br />Rule 4.05.9 - Impoundments <br />7. Colowyo has provided revised page Exh.7-14R-1, which describes the five proposed <br />stock tanks in the Prospect watershed area of the East Pit. The text in the third paragraph <br />of revised page Exh.7-14-R1 does not accurately describe the proposed stock tanks either <br />by name and/or by year of construction when compared to Map 12 and the figures <br />contained in the SEDCAD modeling. This deficiency was identified and discussed <br />during both the 18 August 2010 meeting at the Mine and the 13 October 2010 meeting at <br />the Division's office. Please review the stock tank information provided on revised <br />page Exh.7-14R-1, Map 12 and the SEDCAD modeling and correct this information <br />as necessary. <br />8. Colowyo has provided revised page Exh.7-14R-2, which describes the Prospect <br />watershed condition in three future years, with the 2017 condition identified as the worst