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-29- <br /> o Limited subirrigation potential . <br /> o Assessment of regional practices documented by local SCS personnel <br /> and the results of a published SCS land inventory. <br /> o Professional judgements of Colorado MLRD representatives who <br /> inventoried the site. <br /> o Verbal discussions held with the permittee confirming the nature of <br /> the regional inventory performed. <br /> 3. White River <br /> On the basis of available annual water yield, the presence of unconsolidated <br /> streamlaid deposits, the availability of supplemental moisture through <br /> subirrigation, and the presence of established irrigated lands, the Division <br /> and OSM identify the White River and its associated alluvial deposits as an <br /> alluvial valley floor. <br /> The permittee has supplied sufficient information to address material damages <br /> to the White River AVF. For the most part, the White River lies outside the <br /> permit area. Mining will not take place beneath the river or its alluvial <br /> deposits. The permittee has adequately demonsrtated that bedrock <br /> contributions of ground water from the area to be mined are insignificant in <br /> relation to the flows observed in the White River. Flows to the White River <br /> from Red Wash and Scullion Gulch, which may be impacted by mining, are also <br /> insignificant in relation to the flows observed in the White River. By <br /> minimizing disturbances to Red Wash and Scullion Gulch during mining, the <br /> White River will not suffer material damage via either of these drainages. <br /> At the time of permit issuance, Kenney Reservoir which presently exists within <br /> the project area had not yet been filled. As such, the original findings <br /> document for the Deserado Mine contained an assessment of the potential for <br /> material damage to occur to the White Rier AVF as a result of the permittees <br /> proposed pumping of water from the AVF for use in the mine. The permittee had <br /> demonstrated-that the volume of water removed from the alluvium was <br /> insignificant to the flow volumes observed on the White River even during low <br /> flow years, and had concluded that the effects of drawdown on the alluvial <br /> water body would not significantly impact farming due to the exclusive use of <br /> artificial flood irrigation practices in the area rather than natural <br /> sub-irrigation. This was felt to be a reasonable conclusion, however it was <br /> also felt that natural sub-irrigation may provide additional , supplemental <br /> moisture to flood irrigated crops. In view of this, two stipulations were <br /> attached to the permit to provide for ongoing monitoring of the alluvial body <br /> to verify the anticipated drawdowns caused by pumping, and to provide for the <br /> development of a mitigation plan to protect farming operations in the event <br /> that drawdown of the White River alluvial aquifer had a detrimental effect on <br /> established agricultural activities. A monitoring plan was subsequently <br /> approved and implemented, 'thereby resolving the requirements of the <br /> stipulation. The approved, plan called for monthly monitoring of six alluvial <br /> wells installed within the', White River alluvium above, below, and adjacent to <br /> the alluvial well field utilized to supply water to the mining. operation. At <br /> present, only one well , Qa -5 is monitored due to the complete inundation of <br /> the. remaining wells by rising water levels from the gradual filling of Kenney <br /> Reservoir. <br />