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material resulting from mass wasting and slope wash from the steep slopes rising to <br /> the north of the permit area(see Map 11 of the PAP). The text indicates that, since <br /> settlement in the early 1900's, the area was graded to allow construction of the Fire <br /> Mountain Canal and accommodate flood irrigation. <br /> The affected area occupies a transitional area(mapped as Qc on Map 2 of the PAP) <br /> between the flood plain and terrace complex below(mapped as Qa on Map 11 of <br /> the PAP) and the steeper upland slopes to the north of the permit area. It is the <br /> Division's determination that this transitional area is more appropriately considered <br /> to be an upland area rather than part of the flood plain and terrace complex as <br /> defined in Rules 1.04(10), (142), and (147). <br /> Although colluvial deposits can be considered to be part of unconsolidated alluvial <br /> deposits in many cases, in this particular instance the deposits are fairly deep and <br /> appear to be underlain by bedrock or other fairly consolidated material (on the <br /> basis of test pits and observation by Division personnel). The permit area is also <br /> on a moderately steep slope (15%), which the applicant suggests was previously <br /> graded to accommodate agricultural activity. The type of irrigation practiced on <br /> these colluvial deposits consists of diverting the flow from a nearby irrigation canal <br /> into a system of furrows. This type of irrigation is the only feasible practice under <br /> such steep slope constraints and is considered to be artificial subirrigation rather <br /> than flood irrigation as strictly defined in Rule 1.04(48). <br /> Based on considerations of the nature of the material, steepness of slopes and <br /> irrigation practice, the Division finds that the permit area is more appropriately <br /> considered to be within the upland area relative to the alluvial valley floor and is <br /> not within the flood plain and terrace complex. The Division therefore makes a <br /> negative determination for the presence of alluvial valley floors in the specific area <br /> of proposed disturbance for the Terror Creek operation. <br /> The valley bottom below the proposed disturbance (below the existing railroad <br /> grade) is considered to be an alluvial valley floor. The Division therefore is <br /> required to make a finding for the impact of the disturbance on an adjacent alluvial <br /> valley floor. These findings are presented below. <br /> B. Alluvial Valley Floor Findings <br /> Pursuant to Rules 2.06.8 and 4.24.2, the Division is required to make specific <br /> written findings on the effect of mining upon any alluvial valley floor' s within the <br /> permit and adjacent area. The findings for the North Fork alluvial valley floor are <br /> presented below. Mining activity (construction of the loadout facility)has already <br /> disturbed approximately 13 acres of land on the colluvial slope. No further surface <br /> disturbance is proposed by the applicant. <br /> Pursuant to Rule 2.06.8(5)(a)(i), the Division finds that the surface coal mining <br /> operations would not interrupt, discontinue, or preclude farming on the alluvial <br /> 20 <br />