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sediments are Canyon Creek, the Colorado River, and South Canyon Creek. All the area <br />below the Vulcan ditch can be irrigated with water from Canyon Creek; therefore, this <br />area meets the water availability criteria for an AVF. Water from Canyon Creek cannot <br />be used to irrigate the unconsolidated sediments above the Vulcan ditch due to the <br />physical barrier of elevation differences. In order to irrigate the remaining area from <br />South Canyon Creek and the Colorado River, over 9 and 14 miles of ditch, respectively, <br />would have to be constructed over extremely steep terrain. Water from the Colorado <br />River would have to be diverted in Glenwood Canyon and the ditch would have to be <br />constructed through Glenwood Springs. It is not the regional practice to divert water over <br />extremely rough terrain; therefore, the area above the Vulcan ditch does not meet the <br />water availability criteria for an AVF. The exception to this is the subirrigated area above <br />the Vulcan ditch. <br />Based upon the above discussion, the Division has determined that all the area underlain <br />by unconsolidated streamlaid deposits below the Vulcan ditch plus the small subirrigated <br />area above the Vulcan ditch is an alluvial valley floor. For reference, the alluvial valley <br />floor includes all the area denoted as: (1) land presently flood irrigated; (2) land <br />historically flood irrigated; and (3) areas of probable sub - irrigation, as shown on Figure <br />5.2 -4 in the permit. <br />Colorado River Findings <br />1) None of the proposed mining operation will be located within the alluvial valley <br />floor. Therefore, the Division finds that the proposed operation will not interrupt, <br />discontinue, or preclude farming on the alluvial valley floor. <br />2) Surface waters which supply the alluvial valley floor are diverted from Canyon <br />Creek on the opposite side of the Colorado River from the surface facilities. A total <br />of 115 acres of land are presently flood irrigated. NCIG projects that two to four <br />acre -feet of water per year is required to irrigate each acre of land. Based on historic <br />records, the average flow in the Vulcan ditch is 1,400 acre -feet. Since mining has <br />ceased, other than irrigation of reclaimed areas, NCIG is not proposing any <br />consumptive use of water from the Vulcan Ditch. <br />Irrigation of the reclaimed disturbance area is considered a mining related use. The <br />permittee must, at all times, supply adequate water for flood irrigation of the <br />alluvial valley floor below the Vulcan ditch. If at any time during the irrigation <br />season (May, June, July, August, and September) the flow in the Vulcan ditch drops <br />below 1.6 cubic felt per second, the permittee must receive Division approval based <br />on a demonstration that the water is not necessary for irrigation of the AVF before <br />using the water in the mining operation. <br />The water supply for the subirrigated area near the Colorado River is, as previously <br />discussed, groundwater flow due to irrigation from the Vulcan ditch. Since NCIG <br />has committed to not diverting excessive water for flood irrigation, the source of <br />water for subirrigating this area will not be affected. <br />The source of water for the subirrigated area bisected by the Vulcan ditch is a small <br />Coal Ridge No. 1 Mine <br />Permit Renewal 6 20 31 October 2011 <br />