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drainage area of East Salt Creek. Obviously, the reduction of such a small amount of <br />the drainage area will result in an insignificant reduction of surface flow tributary to the <br />alluvial valley floor. Additionally, all surface runoff retained by the structures will <br />eventually be returned to the system. Runoff from the portion of the mining operation <br />situated along East Salt Creek (87 acres) will also be contained in sedimentation ponds, <br />with the exception of the haul road which connects the central facilities area with the coal <br />processing waste pile. The amount of area essentially removed from the drainage of <br />East Salt Creek due to containment within the sedimentation system is approximately <br />73.2 acres. This accounts for less than six -hundredths of one percent of the drainage <br />area of East Salt Creek below the confluence with Munger Canyon. This will result in an <br />insignificant reduction of surface flow to the alluvial valley floor. As with the sediment <br />ponds situated in Munger Canyon, all surface runoff retained by the structures will <br />eventually be returned to the system. <br />No ground water was encountered within coal seams and their associated roof and floor <br />strata during exploratory drilling in the mine plan area. The applicant, therefore, does not <br />anticipate any significant mine inflow which would require discharging of mine water. <br />Munger Canyon is an ephemeral stream. Therefore, its flow is not sustained by ground <br />water during low flow periods through springs and seeps. If the mine were to <br />experience mine inflows, the ground water depleted from the hydrologic system would <br />not be significant. Therefore, the depletion of ground water will not impact the quantity <br />of water tributary to the alluvial valley floor. <br />The Division has sufficient information to determine the absence of alluvial valley floors <br />in Stove and Buniger Canyons. Sideslopes in the canyons are excessively steep (16 to <br />50%) and are deeply incised. The potential for extensive deposits of unconsolidated <br />alluvium is minimal. Further, because these drainages encompass less drainage area than <br />that of Munger Canyon, it is likely that there is insufficient surface water runoff to sustain <br />agricultural activities. The fact that both streams are ephemeral indicates a low potential <br />for subirrigation by springs or seeps. Inspection of 7.5 minute topographic maps also <br />indicates that there is no irrigation along any stream courses in these drainages. <br />The water quality in Stove Canyon and Buniger Canyon will not be effected by mining <br />since there are no surface disturbances planned in these drainages. The quantity of water <br />in these drainages may be affected to a limited extent if surface waters are diverted <br />into the mine workings through natural or mining -induced fractures. Slopes of the <br />natural surface in the affected drainages range from 2v:Ih to 6v:Ih. On such high angle <br />slopes, rainfall incidental to the surface would have a greater tendency to flow over the <br />surface than to infiltrate into any mine workings. <br />The area of Stove and Buniger Canyons which would potentially be affected by <br />subsidence over mine workings for this permit term is approximately 185 acres. The <br />Big Salt Wash drainage basin encompasses 31,448 acres above the confluence with Stove <br />Canyon. Approximately 0.6% of the drainage area of Big Salt Wash could be effected by <br />the operation in this worst-case scenario. This fact indicates that there is very little <br />35 <br />