2010-06-04_GENERAL DOCUMENTS - C1982056

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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 downstream of Routt County Road No. 27 crossing does not meet AVF criteria due to limited farmable acreage, as was also discussed previously. The alluvial body at the confluence of Foidel Creek and Middle Creek, extending from the County Road No. 33 crossing of Middle Creek upstream on Middle to the first Trout Creek irrigation diversion as depicted on Map No. 15, Water Rights and Alluvial Valley Floors, 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. 1. The proposed mining operations would not interrupt, discontinue or preclude farming on the alluvial valley floor. The mine plan for the Eastern Mining District was shortened from the originally proposed panel length for longwall panels 9R and 8R. Longwall panels in the Eastern Mining District did not undermine the Foidel Creek/Middle Creek Confluence AVE Proposed longwall panels 6R through 2R in Eastern Mining District presented in PR- 04, undermined a portion of Middle Creek; however, the affected portion of Middle Creek is not designated as an AVE 2. The proposed mining operations would not cause material damage to the quantity or quality of surface and ground water that supply the alluvial valley floor. As discussed in the PHC Section of this document, significant dewatering of the Foidel Creek or Middle Creek stream/alluvial systems due to undermining would be precluded by the low vertical permeabilities between the Wadge seam and the alluvia. Stream flow loss to surficial tensional cracks which may develop is expected to be minimal and the fine-grained nature of the alluvium will rapidly fill any cracks that may develop. Furthermore, surface cracking due to subsidence is typically limited to a maximum of 50 feet in depth and direct connection to the workings is not anticipated due to overburden depths in this area in excess of 600 feet. Also, any stream flow loss will be more than compensated by the projected and existing mine discharge to Foidel Foidel Creek Mine 46 June 4, 2010