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<br />-la- <br /> <br />• VII. Alluvial Valley r-Zoors - Rvies 2,06.4 and 4.24 <br />The proposed permit area for the ,Hunger Canyon .Hine occupies parts of four <br />drainage basins distinguishable on a topographic map. These basi.~s include <br />Munger Canyon, Stove Canyon, 3uniger Canyon and an unnamed tributary to <br />East Salt Creek, just south of Munger Canyon. Stove Canyon and Buniger Canyon <br />are sub-basins within the Big Salt :vash drainage sustem. ,Munger Canyon and the <br />unnamed tributary are both sub-basins of the East Salt Creek drainage. <br />The only planned surface disturbance related to the mine will occur within <br />Hunger Canyon. Development of mine workings will extend under portions of <br />all the above-mentioned drainage basins during this 5-year permit term. <br />East Salt Creek has been determined to be an alluvial vaZZey floor. The <br />irrigated agriculture which exists in the East. Salt Creek Valley is evidence of <br />this rnnclusion. The only physical disturbance existing on this alluvial valley <br />floor is the haul road to the mine portals. This is a farm road which existed <br />prior to the operation which was improved slightly for the operation, <br />Unconsolidated alluvial deposits were mapped by the applicant in the lower <br />reaches of Munger Canyon. The proposed waste pile and associated features are <br />located at the edge of these deposits. Exploratory drilling in the Muncer Canyon <br />alluvium by the applicant indicates that ground water is greater than 40 feet <br />below the surface of the va1_'ey floor. .also, the absence of mottling in test <br />pits TP-1, TP-2 and TP-3 indicate the lack of natural subirrigation in the <br />. Munger Creek alluvium. <br />Mean annual discharges in t4unoer Canyon were estimated by the applicant to <br />range from 0.02 efs to 0.48 cfs, with an average of 0.17 c1 s. ;!e an monthly <br />flows were estimated at 0 during winter months and ! c.`s maximum in May. Flow <br />in Munger Creek occurs mainly in response to snowmelt and storm events. <br />The Division has determined that tdunger Canyon does not include an alluvial <br />valley floor. The depth to ground water precludes subirrigation and surface <br />watsr flows are prohibitively Iow for use in successful irrigated agriculture <br />without a means of retaining the flows. <br />s'aZt Creek Mining Company has not supplied information with respect to the <br />aresence of an alluvial valleu floor in the Big Salt Wash, or information on <br />its *_ributaries, Stove Canyon and Buniger Canyon. Therefore, for the purnose of <br />this Findings lbcument, the Division will assume the worst case; that there is <br />a potential alluvial valleu floor in the Fig Salt ;Dash. The following analysis <br />:viii consider potential effects of the operation under this assumption. <br />The Loma loadeut occvnies a rail siding along t.`:e DsR.G~ .4ailrcad right-of-way <br />near the town of Loma, Colorado. This rail iding existed prior to the Ioad- <br />out, and :ras histor_'caliu used as a Loading sic= _`or sucar beets. T.`:e total <br />d_sturSed area at the loadout is S.v acres. <br />• <br />