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-30- Colorado River Findings 1) None of the proposed mining operation will be located within the alluvial valley floor. Therefore, the Division finds that the proposed operation will not interrupt, discontinue, or preclude farming on the alluvial valley floor. 2) Surface waters which supply the alluvial valley floor are diverted from Canyon Creek on the opposite side of the Colorado River from the surface facilities. One of the major sources of water for hydraulic mining will be the Vulcan Ditch. A total of 115 acres of land are presently flood irrigated. Storm King projects that two to four acre-feet of water per year is required to irrigate each acre of land. Based on historic records, the average flow in the Vulcan ditch is 1,400 acre-feet. A maximum of 460 acre-feet (1.6 cfs average flow) will be required to irrigate the AVF during the five month irrigation season, leaving adequate water for use in the hydraulic mining operation. Storm King has committed to supplying adequate water to the AVF even if it means stopping the use of water from the Vulcan ditch by the mining operation. In order to aid the Division in tracking this commitment, the following stipulation is necessary. Stipulation No. 4 THE PERMITTEE MUST AT ALL TIMES SUPPLY ADEQUATE WATER FOR FLOOD IRRIGATION OF THE ALLUVIAL VALLEY FLOOR BELOW THE VULCAN DITCH. IF, AT ANY TIME DURING THE IRRIGATION SEASON (h1AY, JUNE, JULY, AUGUST, AND SEPTEMBER), THE FLOW IN THE VULCAN DITCH DROPS BELOW 1.6 CUBIC FEET PER SECOND, THE PERMITTEE MUST RECEIVE DIVISION APPROVAL, BASED ON A DEMONSTRATION THAT THE WATER IS NOT NECESSARY FOR IRRIGATION OF THE AVF, BEFORE USING THE WATER IN THE MINING OPERATION. The water supply for the subirrigated area near the Colorado River is, as previously discussed, groundwater flow due to irrigation from the Vulcan ditch. As long as Storm King supplies adequate water for flood irrigation, the source of water for subirrigating this area will not be affected. The source of water for the subirrigated area bisected by .the Vulcan ditch is a small ephemeral drainage. The proposed operation will not affect any of the area tributary to this drainage, therefore, there should be no effect on the water supply to this subirrigated area. Based on the above discussion, the Division finds that the proposed operation will not materially damage the quantity and quality of water in the surface and underground water systems that supply the alluvial valley floor or portions of the alluvial valley floor.