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4.05.3 Diversions and Conveyance of Overland Flow and Shallow <br />• Groundwater Flow, and Ephemeral Streams Draining a Watershed Less <br />Than One Square Mile <br />The drainage and sediment control plan described under Section 2.05.6, <br />provides for temporary diversion of surface drainages within the permit <br />area. Temporary ditches, as shown on the Regional Hydrology Map (Map <br />6), will divert runoff out of disturbed areas and, in other cases, be <br />used to divert runoff from disturbed areas. Temporary diversions will <br />be constructed to pass runoff from the precipitation event of a 10-year, <br />24-hour recurrence interval. <br />The temporary diversions will have the purpose of reducing contribution <br />of suspended solids to runoff in diverting undisturbed drainage from the <br />mining area. The diversions will be constructed with a minimum gradient <br />to pass the design flow and will be revegetated with grasses or lined <br />with appropriate riprap. Upon completion of mining and at an <br />• appropriate point mandated in the Coal Regulations of the Colorado Mined <br />Land Reclamation Board, temporary diversions will be reclaimed as <br />required in Section 4.05.17. Additional information on removal and <br />reclamation of temporary diversions is found in Section 2.05.4. None of <br />the proposed temporary diversions will be located so as to increase <br />potential for landslides. Channel lining riprap and energy dissipators <br />will be used when necessary. Peerless Resources does not anticipate <br />that there will be any significant excess material resulting from the <br />construction of diversion ditches. <br />Only one permanent diversion has been designed and will be constructed <br />at the planned operation. Due to previous mining activities, the <br />original channel for Coal Gulch has been completely changed. As <br />explained in Section 2.05.6, Peerless Resources will construct and <br />maintain a new drainage channel for Coal Gulch. Although Coal Gulch is <br />only an ephemeral drainage, the proper construction of a permanent <br />diversion for the drainage will ensure that water is kept away from the <br />• mining area during opewations and long-term integrity of the site will <br />be met fallowing reclamation. <br />4.05-4 <br />