2013-02-01_REVISION - C1981041 (8)

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of the scour protection and transition zone. Scour protection was installed at the outlet of the upper dip section during 2002. Sections of the Coal Canyon permanent channel diversion near Ponds 6 and 10, and the Coal Gulch drainage in the vicinity of Pond 11 were originally planned and approved by the Division to be re- aligned and modified in conjunction with removal of the ponds. The Coal Gulch and sections of Coal Canyon drainage were going to be diverted back through the pond locations which would approximate these drainages original configuration. However, during a meeting between SCC and the U S Corp of Engineers it was recommended that Coal Canyon drainage, which was previously approved for realignment during the reclamation of Ponds 6 and 10, remain in its current configuration. The re- routing of the Coal Canyon and Coal Gulch drainages would require a permit from the U S Corp of Engineers. Carrie Sheate of the US Corp of Engineers proposed that realignment of Coal Canyon for the sake of routing the drainage back to its original contours would not be a justifiable reason for issuing a Corp Permit. The Division concurred with not re- disturbing the current alignment of Coal Canyon and Coal Gulch and approved PR -5 leaving these drainages in their present alignment and configuration. Coal Canyon drainage and Coal Gulch are stable in their current position. Ponds 6 and 10 were backfilled and graded, as depicted in Exhibit 9C, so as not to disturb the current alignment of Coal Canyon. The reclamation plan of Pond 6 included placement of more fill along the toe of CRDA 41, providing additional protection from any possible cutting into the refuse pile. See Appendix 13 -2, pages Misc 13 through Misc 19 of the permit document for details of the current Coal Canyon Runoff and Drainage design. The design information shows that the diversion drains a watershed greater than one square mile and has been appropriately designed to pass safely the peak runoff of a 100 -year 24 -hour event. A second permanent channel diversion has been approved for the lower segment of Coal Gulch in the vicinity of Sediment Pond 11. The pond 11 embankment is located immediately northwest of Coal Gulch. A small portion of this embankment was removed so pond 11 is opened to Coal Gulch. The embankment material and another 3,500 cubic yards from topsoil stockpile number 1 was placed in Pond 11. This material was used to create a positive 0.5% grade so the reclaimed pond 11 area drains to Coal Gulch. Three to five feet of fill was placed in Pond 11 to create this positive drainage. In addition to the permanent diversion of Coal Creek and Coal Gulch, the Division has approved construction of a riprapped permanent channel diversion beginning at the ephemeral drainage above the Roadside South Mine Portal Bench Area, and extending to the south above the Roadside Refuse Disposal Area (RSRDA) and down along the south end of the RSRDA. This diversion was constructed in 2002. Approval of a permanent diversion of an ephemeral channel draining less than one square mile has also been made for a channel in the vicinity of the Two West Portals reclaimed area. The following Findings 1 -3 apply to the Coal Creek and Coal Gulch diversions and the South Portal area permanent diversion; Finding 4 applies to the Two West Portals permanent diversion. The Division has approved permanent diversion of a segment of Coal Creek, a segment of Coal Gulch, and permanent diversion of unnamed ephemeral drainages above the South Mine facilities and the Roadside South Refuse Disposal area. These diversions are consistent with 23