2000-03-10_GENERAL DOCUMENTS - C1980007

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Waters section). However, Flow from these springs would be such a minor contribution of the water supplied to the alluvial valley floor, no degradation of water quality in the alluvial valley floor is predicted. 3. Surface coal mining and reclamation operations are conducted to preserve, throughout the mining and reclamation process, the essential hydrologic functions of alluvial valley tloors not within the affected area (Rule 4.24.2). None of the mining activities are located within the alluvial valley floor and the natural geologic and hydrologic characteristics of the valley floor would not be disturbed. In addition, mining operations are not expected to affect the quantity and quality of surface and groundwater that supply the alluvial valley floor. Minnesota Creek Drainage -Life of Mine AVF Determination: Currently, the West Elk Mine's five-year permit boundary is situated near the Minnesota Reservoir. Mining which could potentially affect the Minnesota Creek intermountain diversion and reservoir system will not be approved until an appropriate subsidence control plan is submitted and approved. One of the locations for alluvial deposits within the life-of-mine permit area is a 90-acre tract of land on the Dry Fork, immediately above Minnesota Reservoir. These alluvial deposits range from 100 to 300 feet in width. The valley floor above the reservoir widens and there is a definite break in slope from the steep sides confining the valley floor. Numerous beaver ponds and willow thickets occupy the valley floor in this location, and grazing is limited to isolated locations along the margins of the valley. The soils in this location are primarily deep clays. The Haplaquoll soil predominates. It is associated with beaver activity and commonly exhibits mottled conditions in subsurface horizons. The alluvial origin of this material is plausible because of the beaver activity and downstream channel blockage from a landsiide and from Minnesota Reservoir dam which was placed at the blockage point. Normally the soil is saturated with water at or near the surface. Because of absence of the good aeration, organic matter content is high. The applicant states that the valley floor in this reach of the Dry Fork would be incapable of supporting agricultural activities without proper drainage. Approximately 20 percent of the total alluvial fill deposits above Minnesota Reservoir have an artificially high water table as a result of backwater conditions from the reservoir pool. This area could not be drained adequately without removing the reservoir. Even with adequate drainage on the remaining 72 acres, the agricultural development would be restricted to grasses and pasture because of the high elevations and short growing season. Furthermore, the beaver ponds and willow thickets are an important factor in the general ecological picture, since they help regulate stream flow, provide water for domestic animals and wildlife. and provide wildlife cover. A letter from the 58