2010-12-17_REVISION - C1981019 (153)

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Surface water 39 • Colowyo Alluvial Valley Floor Analysis Report, Dames & Moore, December, 1995, and • Kennecott Energy Colowyo Coal Company L.P. Jurisdictional Waters Report, JBR Environmental Consultants Inc., September 1998. The existing studies are discussed in chronological order below. The studies were evaluated for the following questions in mind: • Were any AVFs identified? If so, are they significant to farming? • Is the study area adequate for the Collom Pit project? • Does the study contain all of the maps and data required under Section 2.06.8(3)(b) of the Regulations? • Do the conclusions reached seem reasonable and consistent with conditions today? Dames & Moore, 1980 study The original body of work delineating potentially affected AVFs was performed by Dames and Moore in 1980. Areal photographs and topographic maps were used to identify potential AVFs based primarily on geomorphic characteristics in portions of: • Wilson Creek, • Jubb Creek, • Collom Gulch, • Straight Gulch, and • Morgan Gulch. These areas were then field checked, and observations of vegetation, soils, hydrology, and historic land use were made. The report concluded "that the upper reaches of these drainages could be classified as AVFs ". The study concluded that these potential AVFs "have limited economic and agricultural significance to the present ranching and agricultural operations in the area ". The study area for the 1980 evaluation consisted of lands within a 2 -mile radius of a project, which would have mined, primarily in Sections 25, 35, and 36 of T4N, R94W. The currently proposed Collom Mine is expected to operate in areas further south than was the subject of the 1980 Dames and Moore study, including mining in Sections 1 through 4, 11, and 12, T3N, R94W. The D &M study area includes all of Sections 1 through 3 and most of Sections 4 and 10 through 12. • 2572 -R2 Colowyo Coal Company Water Management Consultants