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In Mann Draw, there is insufficient water to support agricultural activities. The stream channel <br />of the draw is small and discontinuous in many Section. There is no existing or historic flood <br />irrigation in the draw. A regional flood irrigation study was conducted in North Park to assess <br />whether flood irrigation was feasible. Both the Canadian and Michigan Rivers and their <br />tributaries were considered in the study (Plate 22 of the permit application). The results of the <br />study show that irrigated watersheds in the region generally flow toward the southwest and have <br />maximum basin elevations from (0,880 to 12,560 feet. Mann Draw is oriented northeast and has <br />a maximum elevation of 8,340 feet. The higher elevated watersheds receive greater than 25 <br />inches of annual precipitation, while Mann Draw receives approximately 10 inches of <br />precipitation annually. <br />Little evidence of subirrigation in Mann Draw was found in the study. Areas where the <br />vegetation suggests subirrigation aze discontinuous and limited to narrow bands along the <br />channel ways. <br />Groundwater <br />Five aquifer systems have been identified in the general azea; the Upper Sandstone member of <br />the Pierre Shale, the Sudduth coal seam, the perched lenticulaz sandstones of the Coalmont <br />Formation, the Upland Terrace deposits, and the alluvium of the Canadian River and its <br />tributazies. <br />The Upper Sandstone member of the Pierre Shale can be considered a regional aquifer, since it is <br />continuous and can transmit limited quantities of water. Pump tests conducted by Kerr Coal <br />Company on this unit yielded a permeability of 0.15 gpd/ft2, thus indicating that the Upper <br />Sandstone member of the Pierre Shale is a poor aquifer. Low permeabilities were obtained by <br />Wyoming Fuel Company in two slug tests run at sites 1C and SA on the siltstone underburden <br />separating the Sudduth coal seam from the Upper Sandstone member. Testing indicated <br />permeabilities of 0.09 gpd/ft2 and 0.01 gpd/ftz, respectively. Kerr Coal Company, in their <br />pumping test, obtained no drawdowns in the Sudduth coal seam while pumping the Upper <br />Sandstone member well located 20 feet away. The results of the two separate sets of aquifer <br />analyses indicate that the siltstone underburden acts as an aquiclude, preventing dewatering of <br />the sandstone member into mine pits. <br />Faults which cut through the mine pits may, however, transmit small quantities of water from the <br />Upper Sandstone member to the mine pits. This had occurred in Wyoming Fuel's Pit 1. <br />Wyoming Fuel had estimated inflows in Pit 2 to be less than 10 gpm. <br />No wells have been completed into the Upper Shale member of the Pierre Shale to date due to its <br />salinity and the low yields. No seeps or springs emanate from the Pierre Shale within the general <br />azea. <br />Bourg Strip Mine. C-81-021 8 August 4, 1998 <br />