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~. However, data from a recent survey of the stream channel through the alluvial body (Application Table 68) indicate the deposits underlying the channel are clays and silty clays with very limited permeability. The applicant has presented evidence that, due to the limited permeabilitiea, recharge of the alluvium by Foidel Creek would be insufficient (5 x 10~ gal/day/sq.ft. of channel) to provide enough water to support subirrigation. &vidence indicates that the alluvium in the vicinity is recharged from upper Williams Fork sandstone unite which occur 10-20 feet below the valley surface. As result, alluvial waters would not be impacted by the increased levels of dissolved constituents in Foidel Creek resulting from high TDS sine water discharge. The proposed operation would preserve, throughout the mining operation, the essential hydrologic functions of the alluvial valley floor. The essential hydrologic functions for this alluvial valley floor have been identified as the capacity to support subirrigated agricultural activities. Since no mining activities would occur within or beneath the alluvial valley floor, and since no material damage would occur to the surface and ground water that supply the alluvial valley floor, the essential hydrologic functions of the alluvial valley floor would not be affected by the proposed operations. Foidel Creek, Middle Creek Confluence Area Map 15 of the life of mine application delineates previously designated alluvial valley floors in the vicinity of the Foidel Creek/Middle Creek confluence, downstream along Middle Creek to the Trout Creek confluence and downstream on Trout Creek to the Yampa River. Map 15 shows a flood irrigated field at the confluence of Foidel and Middle Creek and a number of flood irrigated fields along the Trout Creek AVF downstream from the Middle Creek confluence. In the 1983 Findings for the Foidel Creek Mine, the Division concluded that lower Foidel Creek, lower Middle Creek and lower Trout Creek were alluvial valley floors because of a presumed capability to support flood irrigated and subirrigated agricultural activities. The Trout Creek AVF was addressed previously in this section. Subirrigated alluvium on Middle Creek below the Routt County Road No. 27 crossing does not meet AvF criteria due to limited formable acreage, as was also discussed previously. The alluvial body at the confluence of Foidel Creek and Middle Creek extending from the County Road No. 27 crossing of Middle Creek upstream on both Foidel and Middle to the first Trout Creek irrigation diversion as depicted on Foidel Creek Life of Mine Application Map No. 15 does meet alluvial valley floor criteria based upon existing flood irrigation and a presumed capability to support subirrigated vegetation. These findings do not address areas further upstream on Middle Creek, as they are not hydrologically connected to the proposed mining operation. The required findings for the identified alluvial valley floor at the confluence of Foidel Creek and Middle Creek are set forth below. The proposed mining operations would not interrupt, discontinue or preclude farming on the alluvial valley floor. Proposed mining activity would not directly impact any portion of the confluence AVF, as it is outside of the proposed Foidel Creek Mine Permit Area and would not be undermined or disturbed by proposed surface facilities. 26