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<br />Sage Creek Alluvium, east of the mine site, will not be affected by mining. <br />Surface runoff from the mine will flow to the west, while regional ground <br />water flow appears to be to the west/southwest (see Section V - Ground Water <br />Hydrology). The lower reach of Sage Creek will be adjacent to the tie-across <br />haul road. Impacts to alluvium at this site will also be discussed in this <br />section. <br />At or adjacent to the mine site potential AVF's include alluvium associated <br />with Watering Trough Gulch, Hubberson Gulch, and Dry Creek. The far east and <br />west portions of the tie-across haul road will cross alluvial deposits <br />associated with Sage and Dry Creeks, respectively. <br />Discussions in the text of the permit application, supported by data, indicate <br />that Alluvial Valley Floors exist adjacent to and locally within the permit <br />area. All of the Gulches and drainages mentioned above contain creeks ho]ding <br />stream-laid deposits. There is potential for sub-irrigation, as documented by <br />water level elevations from wells in Watering Trough and Hubberson Gulches. <br />Depth to water measurements show that the water table in each drainage may <br />vary from land surface to about seven feet below the surface. <br />Flood irrigation is regionally practiced in areas similar to Hubberson Gulch, <br />Watering Trough Gulch, Dry Creek and Sage Creek. Hubberson Gulch supplies <br />enough water to flood irrigate approximately 188 acres during the growing <br />season. Sage Creek supplies enough to support seven acres. <br />Water quality samples indicate that, generally, these waters are marginal for <br />irrigation. Analysis of water samples indicated high values of sulfate, <br />magnesium, and total dissolved solids. The applicant states that the <br />continued use of these waters during the growing season for flood irrigation <br />could pose a long term salinity hazard to poorly drained soils. <br />Portions of each of the above mentioned drainages meet the definition of an . <br />Alluvial Valley Floor as defined by the regulations. <br />The Division finds that mining and mine related activities will not impair the <br />prevailing hydrologic balance of and/or impart material damage to Alluvial <br />Yalley Floors in or adjacent to the permit area. <br />Portions of the tie across haul road are located along areas of the Dry Creek <br />Alluvial Yalley Floor which are currently used for hayland. Approximately <br />2.3 acres of hayland will be taken out of production for the tie across haul <br />road. This represents 0.2% of the ]andowner's farming unit. The Division <br />finds that the amount of land taken out of production by the tie across haul <br />road to be an insignificant percentage of farmed land. The area will not be <br />mined and will be reclaimed to reestablish pre-mining productivity. <br />Actual mining activities are conducted a half mile or more from the alluvial <br />deposits of Hubberson Gulch and Dry Creek. The use of diversion and control <br />structures prevents damage to the prevailing hydrologic regime in each <br />drainage. <br />- 20- <br />