2016-05-04_PERMIT FILE - C1982056 (7)

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rhe Fish Creek "ripple Permit Application (C-036-81) submitted in the fall of 1984 and approved by CMLRD on May 20, 1985 addressed the alluvial valley Floor considerations of the Fish Creek Tipple and • I ...toad areas located on the Fish Creek and Middle Creek drainages. CMLRD issued a Decision and Findings Document for the Fish Creek Tipple Permit Area on May 15, 1985. This document concluded that three areas met the geomorphic criteria of alluvial valley Floors. These areas are: I ) the flood plain of Fish Creek; 2) the flood plain of Middle Creek; and , 3) the flood plain of Trout creek. The alluvial valley Iloor determination concluded by saying: 'Based on available information, the unconsolidated streamlaid deposits of Fish and Trout creeks are found to be alluvial valley Floors because of the current or historical existence of flood irrigation and the presumed capability of these areas to support subirrigation during a portion of the growing season. It is significant to note that this statement relative to current historic flood irrigation is applicable only to portions of these to the drainages as a whole. 'I -his historical perspective is provided to answer concerns relative to how and why the areas marked on Map 15, Alluvial Valley Floors and Water Rights was prepared. The basic assumptions used to prepare this map have been accepted in several previous permit submittals prepared by Twentymile Coal and its predecessors, Colorado Yampa Coal and Energy Fuels since the promulgation of the interim OSM Regulations in 1977. As can be observed in each of these individual submittals and as pointed out previously in this discussion, Map 15, Alluvial Valley Floor and Water Rights, contains all geologically mapped unconsolidated deposits as required under Rule 2.06.8 (3)(b). This approach was taker[ as required under 2.06.8(3)(b), following numerous meetings held with CMLRD. These required consultation meetings were initiated in 1978 and have continued with each permitting action up to and including the present submittal. TCC recognizes that this approach presents a "worse case" scenario since it grossly overestimates the actual extent of alluvial deposits by including all unconsolidated geologic deposits into a designation that should more accurately contain only unconsolidated streamlaid deposits. As a result, the actual areal extent of alluvium is considerable smaller that depicted on Map 15, Alluvial Valley Floors and Water Rights. TCC recognizes this inconsistency but believes that the present submittal • is consistent with the regulatory approach of identifying maximum potential impacts and then determining actual anticipated impacts through detailed evaluation. • 'The extent of alluvial deposits associated with potential alluvial valley floors can easily be determined from the detailed soil mapping information presented on Map 17, Premining soils, and in Exhibit 16, Soil Mapping Unit Descriptions. By combining the land forms associated with alluvial valley floors (i.e., alluvial fans, terraces, floodplains, valley bottoms, and alluvial valleys) with mapped alluvium, the delineation of those alluvial deposits potentially associated with alluvial valley floors can be made. This comparison results in the following soil mapping units meeting these two criteria: 2 - Outlet - Slocum Taxajunct complex, 0-2% slopes; 3 - Unnamed - Abel Variant Complex, 0-5% slopes; AW - Aquents-Aquolls Complex; 5A - Absher fine sandy loam, 3%slopes; 23A - Capo clay loam, 0-3% slopes; 27A - unnamed sandy loam, I -10% slopes; 52A - Venable loam, 0-6% slopes; 56A - Tonks loam, 0-5% slopes; and 69c - Milren loans. 0-6% slopes. Upon locating these areas on Map 17, Pre -mining Soils, within the potential alluvial valley floor houndaries presented on Map 15, Alluvial Valley Floors and Water Rights, tlue actual extent of alluvial deposits can be determined. MR 97-1;a 2.06-9 Revised 1110otoi