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the permit area, a CaMgSO~HCO3 water type predominates, and TDS typically ranges from <br />526 to 695 mg/1 at high and low flows, respectively. <br />Most of the flow in Sage Creek is diverted out of the stream for irrigation purposes prior <br />to reaching the site where downstream baseline data was collected. Sage Creek water is <br />also used for livestock watering. <br />Grassy Creek <br />Grassy Creek is a perrenial stream to the east of the permit area. Flow in Grassy Creek <br />upstream from the permit area was perennial during baseline data collection Mean flow <br />rates in the spring, summer and fall were 0.91, 0.10, and 0.06 cfs respectively. A <br />CaMgSO,HCO3 water type predominates upstream from the permit area. TDS ranges from <br />680 to 853 mg/I at high and low flows, respectively. <br />Permit Area <br />Intermittent flows from the northern side of the permit area drain through Armand Draw <br />into Scotchmans Gulch, and then into Grassy Creek. Spring flows in Armand Draw are <br />predominately from the melting of snowpack. Late spring to eazly summer flows are a <br />combination of bank storage, runoff from precipitation events over saturated or frozen <br />ground, or perched spring flow recharged by snowmelt. The remainder of the year, the <br />channel exhibits ephemeral flow characteristics. The mean flow rate in the spring is .056 <br />cfs, and .02 cfs in the summer. <br />Within the permit area, there are five primary drainages, four of which are ephemeral. The <br />drainage channels have been identified as Armand Draw, 011 Draw, Yl Draw, Y2 Draw, <br />and Y3 Draw. Armand Draw is intermittent. The drainage patterns exhibited in these <br />draws aze a combination of parallel and dendritic. The drainage densities are moderate <br />(7.26 to 10.38 mi/mi2), channel sinuosities are low (1.01 to 1.07 mi/mi), and channel <br />gradients are moderate to steep (.039 to .218 ft/fr). <br />Ground Water <br />Aquifers of particulaz interest in the proposed permit area include the coals and <br />interbedded units of the Williams Fork Formation Middle Coal Group as well as the <br />overlying Twentymile Sandstone and the underlying Trout Creek Sandstone. Recharge to <br />the bedrock aquifers occurs as infiltration at the outcrops which are pazallel to the axis of <br />the Fish Creek Anticline. Discharge is through bedrock springs which aze tributary to Sage <br />Creek and one in the upper reach of Armand Draw. Bedrock groundwater is confined <br />except in outcrop areas. <br />Baseline studies showed that the Lennox Overburden and Coal units are artesian flowing <br />aquifers. The Wadge Overburden occurs under confined and unconfined conditions. The <br />Yoast Mine 9 July 6, 1995 <br />