Laserfiche WebLink
Tuttle Draw was considered to be a potential AYF by the applicant based solely <br />upon the identification of unconsolidated stream-laid deposits. The results <br />of the applicant's study indicate that Tuttle Draw does not meet the necessary <br />irrigation criteria to be identified as an AYF, This conclusion is <br />substantiated by the results of an Environmental Protection Agency AYF study <br />(EPA, 1977) conducted in the western United States. The basis for this <br />conclusion is discussed in greater detail below. <br />Geomorphology <br />The applicant has identified about 20 acres along Tuttle Draw which are <br />underlain by unconsolidated stream-laid deposits. These areas are not <br />considered extensive enough to permit the construction of an effective <br />irrigation system. <br />Flood Irrigation <br />Water in Tuttle Draw is not currently diverted for flood irrigation purposes. <br />Water availability and the geomorphic criteria discussed above make it <br />uneconomical to construct a flood irrigation system. <br />An irrigation ditch does cross the northern part of the permit area, This <br />ditch transmits water diverted from the San Miguel River further upstream. <br />Peabody does not propose to disturb this ditch. The ditch does not receive <br />any water from the mine area, Therefore, no mine-related water quality <br />impacts are anticipated for water in the ditch. <br />subirrigation <br />A small amount of subirrigation does occur along the Tuttle Draw stream <br />channel, Much of the alluvial ground water along Tuttle Draw is a result of <br />seepage from the irrigation ditch that was discussed above. In many areas <br />where the subirrigation occurs, the vegetation and soil quickly dry up when <br />the ditch is turned off from October to June. The subirrigation along Tuttle <br />Draw is not considered extensive enough to support agricultural development. <br />Conclusion <br />Based on the preceding discussion, it is concluded that no alluvial valley <br />floors exist in either the permit area or the potentially affected area <br />associated with Nucla Mine. <br />During the Permit Revision No. 1 application review, the Division again <br />assessed the potential for alluvial valley floors in the new permit area or <br />the potentially affected area associated with the Nuc1a Mine. The new areas <br />being added to the permit are incidental area additions to include roads to <br />the ponds and explosive bunker, and topsoil stockpile No. 1. Based on this <br />reevaluation, the Division reaffirms its previous conclusion that no alluvial <br />valley floors exist in either the permit area or the potentially affected area <br />associated with this mine. <br />-14- <br />