2013-10-08_REVISION - C1982056 (22)

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impacts are discussed in the Yampa River CHIA, which is on file at the Division office. Salt loading projections were arrived at by stream flow modeling and analysis of past monitoring results and projected dewatering activities. In a supplemental information package dated September 22, 1986, the applicant submitted information on vegetation cover and production by species for flood irrigated and sub-irrigated croplands on the affected alluvial valley floors. Alluvial bodies, irrigated fields and vegetation sample locations are depicted on supplemental Map No. 1 "Twentymile Park Salt Loading Study Land Use and Hydrologic - Boundaries." This and other information was used by the Division to make the required findings with regard to material damage. Required findings for identified alluvial valley floors on Fish Creek, Trout Creek, and Foidel Creek/Middle Creek confluence are presented separately below. Fish Creek 1.The proposed mining operations will minimally interrupt, discontinue or preclude farming on a portion of the alluvial valley floor. The boundaries of the Fish Creek AVF are as delineated on Map No. 15 of the PAP. The AVF includes all alluvial deposits within and downstream from the permit area as delineated on supplemental Map No. 1. Information discussed below has reaffirmed the Division's original determination that alluvial deposits on Fish Creek meet AVF criteria based on existing flood irrigation, potential for flood irrigation and sub-irrigation. Map 15 shows the following features in the Fish Creek AVF: areas having potential for flood irrigation, currently flood-irrigated fields, diversion structures, and irrigation ditches. Several of the soils in the AVF exhibit late growing season ground water elevations within six feet of the surface (Exhibit 16, Soil Mapping Unit Descriptions and backhoe pit data provided on Page 2.06-9 of the PAP). Hay crop species commonly grown in the Yampa Basin would be expected to benefit from such shallow ground water. The principal vegetation type on the Fish Creek AVF within the permit area is a sagebrush meadow community dominated by silver sagebrush with a number of sedge and rush species contributing significantly to the community. All of these species are hydrophytes typically associated with subirrigated conditions. Rule 4.24.3(1) allows for interruption of farming on “undeveloped rangelands which are not significant to farming…”. The Division received a letter from one of the surface owners, Mr. Edward Camilletti, on January 23, 1998, regarding the significance of the Fish Creek AVF to farming in sections 10 and 15, T5N, R86W. 38 Foidel Creek MineOctober 8, 2013