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the surface. Hay crop species commonly grown in the Yampa Basin would be expected <br />to derive benefit from ground water when present at such depths. <br />The major vegetation type on the Fish Creek AVF within the proposed permit area is a <br />sagebrush meadow community dominated by silver sagebrush with a number of sedge <br />and rush species contributing significantly to the community. All of these species are <br />hydrophytes typically associated with sub-irrigated conditions. <br />Information has not been provided concerning the significance of the alluvial valley floor <br />to farming. Consequently, the Division must assume that the Fish Creek alluvial valley <br />floor is significant to farming and make the three required alluvial valley floor findings. <br />1. The proposed mining operations would not interrupt, discontinue or preclude <br />fazming on the alluvial valley floor. <br />The only mining activity occurring within the boundaries of the AVF was undermining <br />subsidence of a small area of the Fish Creek AVF by the Foidel Creek Mine. The <br />undermined area cottesponded with Foidel Creek Mine's Longwall panels no. 5, 6, and <br />7. No farming activities have been occulting in this vicinity of Fish Creek. Subsidence <br />would not preclude farming of this area. The reclaimed slopes of CYCC's Mine No. 2 <br />drain to Fish Creek but no mining or reclamation operations were conducted within the <br />boundaries of the AVF and CYCC does not propose any future operations which would <br />interrupt discontinue or preclude farming of the AVF. <br />2. The proposed mining operations would not cause material damage to the quantity <br />and quality of surface and ground water that supply the alluvial valley Floor. <br />The potential for subsidence cracking at the surface and subsequent interception and <br />reduction of flow in Fish Creek is minimal. Depths of subsidence cracks produced by <br />tensile stress are generally less than 50 feet. Due to the presence of thick, fine-grained <br />sediments in this area, significant surface cracking is not anticipated. Any cracks which <br />may develop in the stream channel will rapidly heal as alluvial materials collapse in the <br />voids and stresses are relieved due to adjacent subsidence movements. Mining has been <br />completed in this area at the time of PR-03 approval. Hydrologic monitoring data for <br />this area is presented by the applicant in Exhibit Tj of the permit application. An <br />analysis of the data collected is also included. No changes in Fish Creek flow volumes <br />in lower Fish Creek were observed. <br />Surface water quality should not be impacted by subsidence. A slight increase in <br />sediment load may occur as the stream channel gradient is slightly modified due to <br />localized channel slope changes. However, this increase will be localized and is within <br />normal sediment load increases due to spring runoff and normal flow volume increases <br />along Fish Creek. No change due to potential degradation of surface water via ground <br />33 <br />