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• In order to minimize erosion, the pile will be seeded with the temporary seed .mix approved in the Mt. Gunnison Mining and Reclamation Plan (M&R Plan}. (See Table 4.4.5.C. entitled Temporary Seeding Mix in the Mt. Gunnison M&R Plan). Necessary seedbed preparation and seeding of the stockpile will take place in October or November of this year. Hydrologic Protection There are no springs, seeps, or streams located within the area to be disturbed. However the north perimeter of the stockpile will be located within 50 to 25 feet of the North Fork of the Gunnison River. Therefore, as part of this submittal, a variance from the 100-foot stream buffer zone requirement is requested. To prevent degradation of the North Fork of the Gunnison River from this activity a system of ditches, berms and an incised • sedimentation pond will be constructed. As shown in Attachment D, a diversion ditch will be constructed to divert runoff from the undisturbed area above the temporary stockpile. The ditch will be sized to safely pass the peak runoff from the 25-year, 24-hour precipitation event. The ditch will be constructed and maintained to the extent possible to prevent additional contribu- tion of suspended solids to the river. Revegetation of the ditch will be done if necessary to reduce sediment loading, although it is unlikely that this will be necessary, given that the ditch gradient averages 1% and the design runoff velocity from a 25-year, 24-hour event will not exceed 3.1 feet per second. Ditch calculations are presented in Attachment F. As shown in Attachment D, a berm will be constructed between the stockpile and' the river to help prevent disturbed area runoff from entering the river. A ditch on the inside of the berm will be constructed to divert all disturbed area runoff to the incised • sedimentation pond located as shown in Attachment D at the west -3-