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<br />41 <br /> <br />have shown that the primary source of inflows are from fractures in areas <br />of low overburden. <br /> <br />As previously described in this document, MCC encountered a large <br />inflow of water while mining through a fault/fracture system in the <br />B East Mains. As of the date of this findings document, MCC continues <br />to experience mine inflow in the Sylvester Gulch area of the mine. <br /> <br />Groundwater in the area can be expected to flow generally in a downdip <br />(northward) direction, parallel to bedding, toward the deeper part of the <br />Piceance Basin. Data from monitoring wells generally indicate downdip <br />flow, although some closely spaced wells in the Barren Member have <br />highly variable water levels. Some wells are dry, indicating no <br />groundwater flow. Dry wells and variable water levels may result from <br />areal variation in permeability. Generally, springs in the permit area <br />seem to act independently of the bedrock water zones and appear to be <br />surface features related to weathered and fractured bedrock. Springs tend <br />to exhibit highly seasonal flow and discharge only during spring snow <br />melt. Springs recharge and discharge in relatively small areas. <br /> <br />Inflows into underground mine workings from faults and fractures <br />located outside stream valleys generally dry up with time or flow <br />intermittently at discrete points along the fault or fracture. Those which <br />continue to flow have flow rates which diminish to a trickle. Such mine <br />inflows from faults and fractures may represent the dewatering of <br />lenticular sandstone units with limited recharge areas, or may represent <br />flows through fracture zones extending to the surface which have narrow <br />recharge zones on steep slopes. The large initial flow rates are much <br />larger than what would be expected from intergranular porosity in low- <br />permeability sandstone (Darcy-type flow), indicating flow probably is <br />from fractures or faults. <br /> <br />Discharge of groundwater occurs through numerous seeps and springs <br />indentified in the life-of-mine area. The locations of these springs are <br />shown on Map 37 and 37A, Springs and Stock Ponds. <br /> <br />c. Surface Water <br /> <br />The North Fork of the Gunnison River is the principal drainage in the <br />mine area. Smaller streams in or adjacent to the life-of-mine areas are <br />tributary to the North Fork. The North Fork has an average annual <br />streamflow at Somerset of approximately 487.8 cfs per year (1980-2017). <br />Flows in the North Fork usually peak in May or June at around 2,000 to <br />3,000 cfs, and generally range between 50 and 200 cfs during the rest of <br />the year. The flow is regulated by the Paonia Reservoir on Muddy Creek <br />five miles upstream of the town of Somerset. The reservoir became <br />operational in 1962. Water yields during that period have ranged from a <br />high of 601,800 acre feet per year in water year 1984, to a low of 82,270