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basin. The permit area within this drainage is limited to approximately three miles <br />of light use road used to monitor well SK 3.75. The applicant submitted very little <br />information in regard to alluvial valley floor designation of this drainage. Therefore, <br />the Division conservatively assumed that the unconsolidated streamlaid deposits in <br />Alkali Creek comprise a significant alluvial valley floor. <br />Alkali Creek Findings <br />1) None of the light use road is located within the alluvial valley floor. Based on <br />that fact, the Division finds that the proposed operation will not interrupt, <br />discontinue, or preclude farming on the alluvial valley floor. <br />2) The only anticipated effect to surface water in the Alkali Creek drainage is a <br />slight increase in suspended solids. The light use road construction techniques <br />are in conformance with all applicable design standards; therefore, the slight <br />increase in suspended solids should have an insignificant effect on the quality of <br />water in Alkali Creek. <br />There should be no effect on the quantity of water in the Alkali Creek drainage <br />basin due to the light use road. The roads were to be constructed with adequate <br />cross-drains capable of passing the peak flow from a 10-year, 24-hour <br />precipitation event. In addition, there will be no detention structures associated <br />with this road. <br />Based on the above discussion, the Division finds that the proposed operation <br />will not materially damage the quantity and quality of water in the surface and <br />underground water systems that supply the alluvial valley floor or portions of the <br />alluvial valley floor. <br />3) The proposed mining operation will not physically disturb the alluvial valley <br />floor. As discussed above, there will be no effects on the quantity and quality <br />of water supplied to the AVF. Therefore, the Division finds that the proposed <br />mining operations will be conducted to preserve, throughout the mining and <br />reclamation process, the essential hydrologic functions of the alluvial valley <br />floor. <br />Colorado River <br />The applicant identified unconsolidated streamlaid deposits within and adjacent to <br />the proposed permit area which meet the minimum size requirement of 50 feet in <br />width by 10 acres in extent as set by the OSM alluvial valley floor guidelines. These <br />unconsolidated streamlaid deposits border the Colorado River. <br />Three distinct types of unconsolidated deposits were mapped which meet the <br />geomorphic criteria for alluvial valley floors. These deposits are quaternary terrace <br />deposits, quaternary transition zone between terrace and colluvial outwash, and <br />Coal Ridge No. 1 Mine 16 Permit Rcncwal No. 3 <br />