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In addition to the permanent diversion of Coal Creek mentioned above, the Division has <br />approved construction of a riprapped permanent channel diversion beginning at the ephemeral <br />drainage above the Roadside South Mine Portal Bench Area, and extending to the south above <br />the Roadside Refuse Disposal Area (RSRDA) and down along the south end of the RSRDA. <br />This diversion was constmc[ed in 2002. <br />A third major permanent channel diversion has been approved for the lower segment of Coal <br />Gulch in the vicinity of Sediment Pond 11. Excavation of soil from the adjacent Cameo Borrow <br />Area has resulted in a "hanging segment" of the lower Coal Gulch ephemeral drainage. Upon <br />reclamation of Sediment Pond 11, the lower segment of the channel will be re-aligned via a <br />riprap channel segment to direct the drainage to the bottom of the excavated borrow azea. This <br />will result in a topography that is geomorphically stable and appropriate for the permanent <br />drainage configuration. <br />Approval of a permanent diversion of an ephemera] channel draining less than one square mile <br />has been made for a channel in the vicinity of the Two West Portals reclaimed area. <br />The following Findings 1-3 apply to the Coal Creek and Coal Gulch diversions and the South <br />Portal azea permanent diversion; Finding 4 applies to the Two West Portals permanent diversion. <br />1. The Division has approved permanent diversion of a segment of Coal Creek, a segment of <br />Coal Gulch, and permanent diversion of unnamed ephemeral drainages above the South <br />Mine facilities and Roadside Refuse Disturbance area. These diversions are consistent <br />with applicable state law, will not diminish downstream water rights, and will meet the <br />requirements of Rules 4.05.4 and 4.05.1 S (4.05.4(4)). <br />2. The permanent diversions shall make use of artificial structural controls in order to allow <br />them to remain in dynamic equilibrium with the drainage basin system. The Division <br />approves the use of rip-rap channel lining along various segments of these channels. <br />3. Channel lining structures and artificial channel roughness stmctures are proposed for use to <br />control erosion. Artificial structures include arip-rap transition zone structure in the Coal <br />Creek channel at the location of the former Haul Road 2 crossing, and riprap lining along <br />the South Portal facilities permanent diversion and the Coal Gulch permanent diversion <br />segment. These means were approved by the Division since they aze necessary to control <br />erosion, they aze stable and will require infrequent maintenance (4.05.4(2)(a)). <br />4. In addition to the permanent diversions mentioned above, a pem~anent diversion of an <br />ephemeral stream draining less than one square mile has been approved for an unnamed <br />ephemeral tributary to the Colorado River located within the 2 West Portal Disturbance <br />Area. The outside bank closest to the North Portal was built up to prevent the diverted <br />stream from entering the portal. Bedrock lies close to the bottom of the diverted channel <br />and the channel does not require armoring. This decision is based on a fmding that the <br />proposed diversion meets the requirements of 4.05.18 and 4.05.4, applicable local, State, <br />and Federal statutes and regulations and that the diversion is designed to safeguard public <br />safety and to minimize adverse impacts to the hydrologic balance (4.05.4(1) and (4)). <br />25 <br />