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Twentymile Coal, LLC (TC) <br />Narrative <br />Lease by Modification Application Wolf Creek Reserve — April 2014 <br />responding to the requirements of Rule 2.06.8(4). This report has been incorporated into <br />Exhibit 4e-2 of the Mining and Reclamation Permit (Permit No. C-82-056). The following <br />information from this permit is incorporated into this application by reference. <br />The soils information presented in the Kaman Tempo report was updated to reflect <br />subsequent work by Habitat Management, Inc., and a copy of their report is presented in <br />Exhibit 4e-4 (Foidel Creek Mine Permit C-82-056). Additionally, chemical and physical <br />properties of the dominant soil type for the Fish Creek AVF, Binco Silty/Clay Loam, are <br />presented in Table 73. None of the data presented, indicate any significant concerns with this <br />soil relative to seasonal flooding or increased sub -irrigation. As an example, the low sodium <br />adsorption ratio (SAR) for this soil indicates that leaching will not be problematic relative to <br />soil characteristics and productivity, or water quality downstream of the mined area. The <br />original data presented on this table was taken from Table 72 of Colorado Yampa Coal <br />Company Permit C-1981-071. The conclusions presented in the report agree with TC's <br />contention that subsidence of portions of the Fish Creek AVF will not materially damage <br />either the AVF, its essential hydrologic function, or associated land uses. It should be noted <br />that the Kaman Tempo report was prepared in 1982, and since that time, land <br />use/management practices have not changed, i.e. large acreage ranches with seasonal <br />livestock grazing to meet the economic requirements of the marketplace. This ownership/use <br />pattern continues in the Twentymile Park Basin. <br />The only surface owners that would be directly affected by any subsidence -related impacts to <br />Fish Creek or the associated AVF are TC. Immediate downstream surface owners are <br />limited to TC and Ashley Investments. The only potentially affected upstream surface <br />owners are Rogers and Rice. Although adverse impacts are not anticipated, TC previously <br />contracted with Habitat Management, Inc. to conduct a baseline vegetation study of the Fish <br />Creek AVF to identify and evaluate vegetation communities and productivity, as a basis for <br />identification, evaluation, and any necessary mitigation. <br />There are no known irrigation head -gates located within the proposed mining area, indicating <br />that flood -irrigation of these bottom lands has not previously occurred and is probably not <br />practical, and that any enhancement of vegetative growth in the AVF areas probably results <br />from sub -irrigation. Subsiding portions of the AVF will tend to increase the potential for <br />sub -irrigation to occur by lowering the stream base level and adjacent terrain relative to <br />normal seasonal flow levels. <br />It is anticipated that for the portion of the Wolf Creek Reserve where Fish Creek will be <br />undermined, the response of the Fish Creek channel to subsidence will be essentially the <br />same as previously experienced where Fish Creek was undermined in TC's EMD and NMD. <br />The entire length of Fish Creek overlying mining areas was surveyed for outcrop areas. The <br />survey showed that approximately 1,260 feet of channel in Section 10, T5N, R86W (NMD) <br />is underlain by an exposed outcrop of the Fish Creek Sandstone. In this area, the potential <br />existed for subsidence -related fractures to develop, resulting in drainage from the stream to <br />bedrock. Subsidence evaluations, however, indicated that overburden depth, combined with <br />WCR BLM Lease App Narrative 0414.docx Page 8 <br />