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Creek, Sylvester Gulch, and the North Fork of the Gunnison River (Exhibit <br />2. 8.4.B). <br />Tc,~o of these areas, ?fi nnesota Creek and Dry Fork :~!inesota Creek, althouch geo- <br />graphically adjacent to the permit area, are not hydrologicallu adjacent to <br />the activities being re vie,.~d _.. ts:is cer.~~t a~tlicat'c~. __-: _ s`-.==a <br />crater disida and a gro::nd ,Tatar divide (=xhibit 2.5.2.:J separate tr.~se <br />areas Eton the mining actin ties beino perritted. =cric~ltura: ___a_ <br />currentl exist along .,_:nesota Creek, and the a_a~ is __.._a..=_ ,>.. a_....-_a_ <br />valley floor. However, a formal determination for either of these two areas <br />wi1Z not be made at this time. [then the applicant submits an application <br />that proposes mining activities within either the surface watershed or ground <br />water system for these areas, the Division will make the required alluvial <br />valley floor determinations. <br />A third area is located along Sylvester Gulch. As identified in the Mt. <br />Gunnison application, this area is approximately 20 acres in size. Examination <br />of the Division's aerial photography suggests that the area of possible fill <br />may be considerably smaller. The applicant notes (page 2-34a) that the <br />"alluvial origin of the valley deposits at this location is doubtful". The <br />non-alluvial origin of this fill is confirmed by geologic mapping by the <br />Colorado Geological Survey (lunge, 1978, see attached map) which identifies <br />the fill material as colluvial-wedge deposits formed by gravity-dominated <br />processes (Qcw). On the basis of this information, this area is found not <br />to meet the geomorphic criterion for an alluvial valley floor. <br />The fourth area identified as having alluvial deposits is located along the <br />North Fork of the Gunnison River. Deposits located upstream of the proposed <br />operations are not a part of the hydrologic system that could be effected, <br />and no determination will be made at this time. The first area of uncon- <br />solidated streamlaid deposits adjacent to the permit area is found at the <br />mouth of Sylvester Gulch, This area is identified by the applicant as being <br />an alluvial fan and is excluded by the applicant from alluvial valley floor <br />consideration because it is an upland area by definition (page 2-343d). The <br />Division rejects this argument. The definition of upland areas (Rule 1.04 <br />(147j)only excludes Iandforms, such as alluvial fans, rohen they are located <br />outside the floodplain and terrace complex. The area in question is clearly <br />located within the valley bottom landform. However, this area is found rot <br />to be an alluvial 6a11ey floor. 't'he Colorado Department of Highways is in <br />the process of relocating State Highway 133 to cross the site under consideration. <br />As a result, any determination that the site is an alluvial valley floor is <br />pointless. <br />Between Sylvester Gulch and the town of Somerset, several smaller bodies of <br />alluvium lie along the course of bhe river. Two of these areas are occupied <br />by the Bear hfine Portal and Bear loadout. None of these areas meet the size <br />criteria of the OSt~ technical guideline (10 acres), and these areas are found <br />not to be alluvial valley floors. <br />Downstream from the town of Somerset, the valley opens up and the applicant <br />has identified a much larger body of alluvium, Areas within Sections 13 and 14 <br />have been identified as currently supporting agriculture. No specific <br />information has been provided concerning flood irrigation (existing or <br />