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Hay Gulch. Field observations by Division staff and information contained in <br /> permit applications indicate that small areas of unconsolidated stream-laid <br /> materials are present in tributary drainages, where the King I and King II <br /> surface facilities are located. These smaller areas do not meet the size criteria <br /> for AVFs. <br /> It has been determined that Hay Gulch does meet the criteria for an AVF <br /> based on the following findings: (1) The valley contains unconsolidated <br /> stream-laid deposits; (2) The valley contains sufficient water to support <br /> agricultural activities as evidenced by (a) the historical use of flood irrigation <br /> in the area, and (b) the demonstrated capability of the area to be flood <br /> irrigated, and (3) the valley has demonstrated subirrigation. <br /> Hay Gulch does not contain a stream channel, probably because the original <br /> channel was plowed over and smoothed out to facilitate hay production and <br /> grazing. Surface water flow in the gulch is diverted upstream of the permit area <br /> into the Hay Gulch Irrigation Ditch, which parallels La Plata County road 120. <br /> The Hay Gulch Irrigation Ditch is used for flood irrigation in the vicinity of <br /> the King I and II Mines. The naturally occurring water table of the AVF <br /> fluctuates from just above the ground surface to a few feet below the surface. <br /> This ground water supply is sufficient to provide sub-irrigation on the AVE <br /> The land use on the AVF is primarily pastureland with occasional hay <br /> production. The essential hydrologic functions that supply water to the AVF <br /> are flood irrigation and subirrigation as described above. Absent information <br /> to the contrary, the AVF is considered significant to individual farming units <br /> in the area. <br /> Degraded water from the King I and II Mines could infiltrate Hay Gulch <br /> alluvium either from the mines' ponds or haul roads. The infiltrating volumes <br /> would be so small compared to the volume of natural flow in the alluvium that <br /> the natural flow would readily dilute and attenuate the infiltration. The <br /> Division concludes that the mines have been designed to minimize impacts to <br /> the AVE <br /> The Pine Gulch drainage crosses through the southern end of the King I area of <br /> the permit. Sufficient information has been supplied by the operator in <br /> regard to Pine Gulch, and confirmed in the field by the Division,to make the <br /> determination that Pine Gulch does not contain an alluvial valley floor (AVF) <br /> within the permit area. While there are limited alluvial deposits in Pine Gulch, <br /> they are not currently flood irrigated for agricultural purposes and have not <br /> been cultivated historically. Due to the limited surface water availability in <br /> 26 <br />