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determination that subiriga[ed areas were less than 10 acres in extent and supported species which <br />were not agriculturally useful. <br />Due to the significant expansion of mining operations proposed in the LOfvl revision application <br />(PR-01), the potential impacts to identified alluvial valley Floors were reevaluated. Areas previously <br />determined by the Division to not meet alluvial valley Floor criteria were no[ reexamined. As a result <br />of additional vegetation data and land use information submitted by [he applicant and site visits made <br />by Division staff, however, certain lands previously identified as alluvial valley Floors were found not <br />to meet AVF criteria. <br />Based on the limited extent of arable land and relatively high percentage ofnon-agriculturally useful <br />species as documented by species composition data included in the September 22, 1986 submittal, the <br />Division concluded that the area of subirrigated alluvium on lower Foidel Creek denoted as "Pasture <br />19" on supplemental Map No. I is not an alluvial valley floor. The extent of formable acreage would <br />be l0 acres or less. The areas are not presently and have not historically been farmed and evidence <br />presented indicates that farming is not typically practiced on similar parcels in the region. <br />During PR03 review, the Division determined that azeas upstream of the Leiske ditch crossing of <br />Foidel Creek as shown on Map 15 (Sections 14, 21, 22, 23, and 28, TSN, R86W) are not alluvial valley <br />floors. This determination was based on the lack of sufficient water for flood irrigation, the lack of <br />flood irrigation, the small size of the valley bottom and the narrow nature of the stream, and the lack of <br />meaningful production or cover differences between the creekside and upland vegetative communities. <br />Therefore, in summary, the Division finds that all valley bottom areas along Foidel Creek above the <br />County Road No. 33 crossing are not alluvial valley floors. <br />Middle Creek <br />Prior to PR-03, no previous AVF determination had been made for areas above the Foidel/Middle <br />Creek confluence AVF on Middle Creek as these areas were not proposed to be affected or impacted by <br />the Foidel Creek mine operation. During the PR-03 review process, the applicant submitted <br />information to support that areas along the Middle Creek valley floor in sections 12, 23, and 26 TSN <br />R86W are not alluvial valley floors. Twenrymile Coal Company provided information which is <br />contained in the permit application as Exhibit 42a and consists of vegetation sampling data, valley floor <br />cross-sections, and a ttansect location maps. The applicant also refers to the narrow and deeply incised <br />nature of Middle Creek. <br />There is no indication of past or current flood irrigation of these areas along Middle Creek and the <br />geomorphic characteristics of this area would not lend themselves to the development of an irrigation <br />system. Based on the lack of Flood irrigation potential, the narrow and incised nature of the valley <br />bottom, and the lack of meaningful differences between the creekside and upland vegetative <br />communities, the Division has determined that areas upstream of the Connel ditch lateral crossing of <br />Middle Creek, as shown on Map l5, are not alluvial valley floors. In this case, the extent of formable <br />acreage would be 10 acres or less. The areas are not presently and have not historically been farmed <br />and evidence presented indicates that farming is not typically practiced on similar parcels in the region. <br />A previous negative determination had already been made far those lands along Middle Creek <br />downstream from the County Road No. 33 in section l2 to the first irrigation ditch crossing (Connel <br />ditch lateral). <br />Effects of Minine on identified Alluvial Valley Floors <br />C:U H B\C82056\R N03\RN03FIND.doc <br />28 <br />