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perched spring flow recharged by snowmelt. The remainder of the year, the channel exhibits <br /> ephemeral flow characteristics. The mean flow rate in the spring is .056 cfs, and .02 cfs in the <br /> summer. <br /> Within the permit area, there are five primary drainages, four of which are ephemeral. The <br /> drainage channels have been identified as Annand Draw, 011 Draw, Yl Draw, Y2 Draw, and <br /> Y3 Draw. Armand Draw is intermittent. The drainage patterns exhibited in these draws are a <br /> combination of parallel and dendritic. The drainages densities are moderate (7.26 to 10.38 <br /> mi/mi2), channel sinuosities are low (1.01 to 1.07 mi/mi), and channel gradients are moderate to <br /> steep (.039 to .218 ft/ft). <br /> Ground Water <br /> Aquifers of particular interest in the permit area include the coals and interbedded units of the <br /> Williams Fork Formation Middle Coal Group as well as the overlying Twentymile Sandstone <br /> and the underlying Trout Creek Sandstone. Recharge to the bedrock aquifers occurs as <br /> infiltration at the outcrops, which are parallel to the axis of the Fish Creek Anticline. <br /> Discharge is through bedrock springs tributary to Sage Creek, and one in the upper reach of <br /> Armand Draw. Bedrock groundwater is confined 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 /> unconfined conditions are encountered near the outcrops. The saturated aquifer thickness of <br /> these units range between 4 and 200 feet. <br /> The Wadge Coal aquifers appear to be largely confined, whereas the Wadge Underburden <br /> aquifer occurs under both confined and unconfined conditions. The Wolf Creek Coal occurs <br /> under confined conditions; however, the Wolf Creek Underburden is both unsaturated and <br /> unconfined. <br /> Structural folding and faulting as well as stratigraphy control groundwater movement in <br /> bedrock aquifers. Confined conditions occur at synclinal axes, while unconfined conditions <br /> occur near the outcrops. No significant faulting is known to occur within the permit area. <br /> Two recharge boundaries are known to exist in the permit area. An erosional face along the <br /> northerly plunging axis of the Fish Creek Anticline provides a localized recharge boundary for <br /> the Wadge Coal and Wadge Overburden. Additionally, the Wolf Creek Coal outcrop, parallels <br /> the axis of the Dish Creek Anticline, comprises a recharge boundary for the Wolf Creek Coal. <br /> In general, the Williams Fork Formation, which includes the Twentymile Sandstone and the <br /> Middle Coal Group, has yields of up to 100 gallons per minute (gpm). The average yield is <br /> approximately 10 gpm. The underlying Trout Creek Sandstone has a yield of approximately 5 <br /> gpm and occurs under confined conditions with an artesian head of 30 feet above the ground <br /> surface. <br /> Alluvial aquifers in the permit area include the Sage Creek alluvium, Armand Draw alluvium <br /> and Grassy Creek alluvium. The Sage Creek alluvium has a saturated thickness of between 7.5 <br /> and 56 feet. Armand Draw alluvium and Grassy Creek alluvium have a saturated thickness of <br /> 12 and 11-28 feet, respectively. Groundwater occurs under unconfined conditions in the <br /> 7 <br />