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The boundaries of the Fish Creek AVF are as delineated on Map No. 15 of the PAP. The AVF <br />includes all alluvial deposits within and downstream from the permit area as delineated on <br />supplemental Map No. 1. Information discussed below has reaffirmed the Division's original <br />determination that alluvial deposits on Fish Creek meet AVF criteria based on existing flood irrigation, <br />potential for flood irrigation and subirrigation. <br />Map 15 shows the following features in the Fish Creek AVF: areas having potential for flood <br />irrigation, currently flood-irrigated fields, division structures, and irrigation ditches. <br />Several of the soils in the AVF exhibit late growing season ground water elevations within six feet of <br />the surface (Exhibit 16, Soil Mapping Unit Descriptions and backhoe pit data provided on Page 2.06-9 <br />of the PAP). Hay crop species commonly grown in the Yampa Basin would be expected to benefit <br />from such shallow ground water. <br />The principal vegetation type on the Fish Creek AVF within the permit area is a sagebrush meadow <br />community dominated by silver sagebrush with a number of sedge and rush species contributing <br />significantly to the community. All of these species are hydrophytes typically associated with <br />subirrigated conditions. <br />Rule 4.24.3(1) allows for interruption of farming on, "undeveloped rangelands which are not <br />significant to farming..." The Division received a letter from one of the surface owners, Mr. Edward <br />Camilletti, on January 23, 1998, regarding the significance of the Fish Creek AVF to farming in <br />sections 10 and 15, T5N, R86W. The Camelletti's use these lands as undeveloped rangeland. The <br />landowner estimated that 1 % of the ranch production is attributed to the Fish Creek AVF. <br />Twentymile Coal Company owns a significant portion of the lands in and adjacent to the Fish Creek <br />AVF. Twentymile Coal Company operates a cattle operation on these lands and manages the land, <br />through its ranch manager, Trout Creek Ranch, as undeveloped rangeland. TCC does not utilize the <br />Fish Creek AVF as cropland. TCC projects that impacts to the Fish Creek AVF will not significantly <br />impact the cattle operation. <br />Technical Revision No. 14 (TR14) approved the undermining and subsidence of a small portion of <br />Fish Creek due to longwall extraction in panels 5, 6 and 7 in the Southwest Mining District. No <br />farming activities are currently undertaken along Fish Creek in this area. Subsidence did not preclude <br />the farming of this area. <br />Fish Creek was the only AVF approved to be undermined as a result of Permit Revision No. 6 (PR6). <br />No stream pirating or loss of flow was experienced during the mining approved by PR6. <br />The proposed mining operations would not cause material damage to the quantity and quality of <br />surface and ground water that supply the alluvial valley floor. <br />The only significant degradation of the stream water from TCC's mining operations has been caused <br />by pumping of underground mine water into Fish Creek and Foidel Creek. Data in TCC's annual <br />hydrology reports document this degradation. Pumping occurs at two sites, 115 (Fish Creek borehole) <br />and 109(portal area). The pumping loads the streams with dissolved solids, mainly sulfate. The <br />operator has maintained stream water quality below the material damage threshold by limiting the <br />pumping rates at both sites and treating the pumped water at one of the sites, 115. The operator <br />proposes no change in PR8. The operator will continue to limit pumping rates and treating water as in <br />the past; therefore, mine pumping can be expected to not cause material damage to the quality of <br />surface or alluvial water. <br />29