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diversion of an ephemeral channel draining less than one square mile has also been made <br /> 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 <br /> South Portal area permanent diversion; Finding 4 applies to the Two West Portals <br /> permanent diversion. <br /> 1. The Division has approved permanent diversion of a segment of Coal Creek, a <br /> segment of Coal Gulch, and permanent diversion of unnamed ephemeral drainages <br /> above the South Mine facilities and the Roadside South Refuse Disposal area. These <br /> diversions are consistent with applicable state law, will not diminish downstream <br /> water rights, and will meet the requirements of Rules 4.05.4 (4.05.4(4)). <br /> 2. The permanent diversions shall make use of artificial structural controls in order to <br /> allow them to remain in dynamic equilibrium with the drainage basin system. The <br /> Division approves the use of rip-rap channel lining along various segments of these <br /> channels. <br /> 3. Channel lining structures and artificial channel roughness structures are proposed for <br /> use to control erosion. Artificial structures include a rip-rap transition zone structure <br /> in the Coal Creek channel at the location of the former Haul Road 2 crossing, and <br /> riprap lining along the South Portal facilities permanent diversion and the Coal Gulch <br /> permanent diversion segment. These means were approved by the Division since <br /> they are necessary to control erosion, they are stable and will require infrequent <br /> maintenance (4.05.4(2)(a)). <br /> 4. In addition to the permanent diversions mentioned above, a permanent diversion of <br /> an ephemeral stream draining less than one square mile has been approved for an <br /> unnamed ephemeral tributary to the Colorado River located within the 2 West Portal <br /> Disturbance Area. The outside bank closest to the North Portal was built up to prevent <br /> the diverted stream from entering the portal. Bedrock lies close to the bottom of the <br /> diverted channel and the channel does not require armoring. This decision is based on <br /> a finding that the proposed diversion meets the requirements of 4.05.18 and 4.05.4, <br /> applicable local, State, and Federal statutes and regulations and that the diversion is <br /> designed to safeguard public safety and to minimize adverse impacts to the hydrologic <br /> balance (4.05.4(1) and (4)). <br /> D. Sedimentation Ponds <br /> Information on the surface water sediment control system can be found in Volume 3, <br /> Tab 13, page 13-5 of the permit application. A list of sediment control structures, <br /> along with references to appropriate exhibits for designs and cross sections, are found <br /> in Table 13-4 of the application. Calculations used to design these structures are given <br /> in appendix 13-2 of the permit application. <br /> During operations a total of 12 sediment ponds were designed and built and treated <br /> disturbed-area surface water runoff under the existing permit for the Roadside Mines. <br /> 26 <br />