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East Salt Creek has been determined to be an alluvial valley floor. The irrigated agriculture which exists in the East Salt Creek Valley is evidence of this conclusion. Irrigated cropland as well as areas used for grazing are shown on Figure 4.1-15 of Volume VII of the permit application. Unconsolidated alluvial deposits were mapped by the applicant in the lower reaches of Munger Canyon. The proposed underground development waste pile and associated features are located at the edge of these deposits. Exploratory drilling in the Munger Canyon alluvium by the applicant indicates that ground water is greater than 40 feet below the surface of the valley floor. Also, the absence of mottling in test pits PT-1, TP-2, and TP-3 indicate the lack of natural subirrigation in the Munger Creek alluvium. Mean annual discharges in Munger Canyon were estimated by the applicant to range from 0.02 cfs to 0.48 cfs, with an average of 0.17 cfs. Mean monthly flows were estimated at 0 during winter months and 1 cfs maximum in May. flow in Munger Creek occurs mainly in response to snowmelt and storm events. The Division has determined that Munger Canyon does not contain an alluvial valley floor. The depth to ground water precludes subirrigation and surface water flows are prohibitively low for use in successful irrigated agriculture without a means of retaining the flows. Salt Creek Mining Company has not supplied information with respect to the presence of an alluvial valley floor in the Big Salt Wash. Therefore, for the purpose of this findings document, the Division will assume the worst case; that there is a potential alluvial valley floor in the Big Salt Wash. The following analysis will consider potential effects of the operation under this assumption: The only direct effects to the Colorado River could be from the Loma loadout which occupies a rail siding along the D&RGW Railroad right-of-way near the town of Loma, Colorado. This rail siding existed prior to the loadout, and was historically used as a loading site for sugar beets. The total disturbed area at the loadout is 5.6 acres. The loadout is roughly two miles from the Colorado River. All runoff, which only results from direct precipitation over the 5.6 acre disturbance, will be contained at the site, and no runoff will he discharged from the site. Due to the limited surface disturbance, the potential impact of the loadout on the Colorado River alluvial valley floor is insignificant. Alluvial Valley Floor Findings With Regard to Farming The only identified alluvial valley floor area to be affected by mining operations lies within the East Salt Creek alluvium. The central facilities area will affect approximately 43.4 acres of the East Salt Creek AVF. The applicant has calculated the significance of this area to farming in the pre-mining farming unit. The existing ranch runs approximately 793 animal units. Based upon assumption that the -44-