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that farming would not be interrupted, discontinued or precluded; proposed operations would not cause material damage to quantity and quality of suzface and ground water that supply the AVF, and the proposed operation would be conducted to preserve the essential hydrologic functions of the AVF. An alluvial body on Foidel Creek downstream from the permit area below the water gap in Sections 21, 22 and 28 (TSN, R86W) was determined to be an AVF based on an assumed capability to support subirrigation. As in the case of Fish Creek, findings were made to the effect that the AVF would not be negatively impacted by the proposed mining operation. An alluvial body upstream from the water gap in section 28, 29, 31 and 32 (TSN, R86W) was detezmined not to be an AVF based on a finding of insufficient water to support flood irrigation and a determination that subirrigated areas were less than 10 acres in extent and supported species which were not agriculturally useful. Alluvial deposits in the vicinity of the Foidel Creek/Middle Creek confluence and alluvial deposits on lower Middle Creek and Lower Trout Creek (helow Middle Creek confluence) were found to be alluvial valley floors because of a presumed capability to support flood irrigation and subirrigated crops. Again, findings were made that the alluvial valley floors would not be negatively impacted by the proposed mining operation. Due to the significant expansion of mining operations proposed in the LOM revision application, the potential impacts to identified alluvial valley floors have been reevaluated. Areas previously determined by the Division to not meet alluvial valley floor criteria were not reexamined. As a result of additional vegetation data and land use information submitted by the applicant and site visits made by Division staff, however, certain lands previously identified as alluvial valley floors have been found not to meet AVF criteria. Based on the limited extent of arable land and relatively high percentage of non-agriculturally useful species as documented by species composition data included in the September 22, 1986 submittal, the Division has concluded that the area of subirrigated alluvium on lower Foidel Creek denoted as "Pasture 19" on supplemental Map No. 1 is not an alluvial valley floor. A negative determination has also been made for sub-irrigated portions of Middle Creek between the Foidel Creek confluence and the first Trout Creek irrigation diversion in Section 12, TSN, R86W due to the limited extent of farmable acreage resulting from the narrow alluvial body (averaging less than 500' in width) which is bisected by the meandering channel of Middle Creek. In both instances the extent of farmable acreage would be 10 acres or less. The areas are not presently and have not historically been farmed and evidence presented indicates that farming is not typically practiced on similar parcels in the region. Effects of Mining on Identified Alluvial Valley Floors Due to elevated levels of salinity documented in current mine discharge water and projected for future mine discharge and potential inhibitory effects of increased soil and alluvial ground water salinity on flood irrigated and subirrigated crops, the potential for material damage caused by salt loading was a major concern which had to be evaluated for each of the alluvial valley floors. Material damage projections were calculated in both a sub-irrigation and a flood irrigation case analysis, using data obtained during low-flow-of -record years (see TABLE 17 contained in Section IX (CHIS) of this Findings Document). The subirrigation scenario assumed that the stream would recharge the alluvial aquifer in the spring during 19