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conclude that the mining operation could result in channel cut-off causing the Poudre River to <br />shortcut through the gravel mine or ponds created from it. In order to prevent this from <br />occumng, the report recommended two options: first, leaving a 440 foot strip of undisturbed land <br />between the mine excavation and the edge of the river on the northern border with the river or, <br />second, constructing a concrete rubble wall on the order of 50 feet wide extending the width of <br />the mined area on the northern border with the river. <br />2.2 Development and Utility Easements <br />Two other factors contribute to the reduction of the mining area. Kehn is considering the <br />preservation of two portions of the property for later commercial development. These areas <br />would probably not be mined. There are also two utility easements that have to be respected <br />during the mining and reclamation process. The two portions of the property Kehn is <br />considering for future commercial development are the 18.9 acre area at southwest corner of the <br />property and fhe 16.4 acre area on the west side that currently houses their offices and. asphalt <br />plant. The two areas are labeled on Figure 2.1 and further reduce the mining area to 226.7 acres. <br />One natural gas pipeline and one fiber optic telecommunications cable run north to south through <br />the property. As shown on Figure 2.1 the utilities easements are 540 feet apart and each has an <br />easement of 100 feet. Careful consideration was given in the reclamation plan to the areas over <br />the utility easements to avoid any permanent excavations (i.e. ponds) that might conflict with the <br />utilities. In the reclamation plan the ground over the utilities was put into wetlands or other uses <br />that will provide adequate cover. In some areas the boundaries of the mining phases were <br />adjusted to insure full coverage of the utility easements under the desired use. This results in <br />differences between the net and allocated areas in each phase. <br />2.3 Depth of Mining <br />Plans for reclamation, mitigation, and economic optimization of the Timnath Pit are <br />dependent upon the depth to which the pit will be mined. The reclamation plan and final layout <br />were developed under the assumption that each phase of the pit will be mined to bedrock. From <br />experience, observations, and other data the depth to bedrock in the area of the Timnath Pit has <br />been assumed to average 15 feet below the ground surface. The surface contour of the bedrock <br />is also assumed to follow the contour of the ground surface. Calculations of the volume of <br />removed material, final storage of reclaimed ponds and fill volume requirements are based upon <br />this assumed mining depth. It was further assumed that after grading and lining the bottom of <br />T:IOPEMCodkcOllcodkc0/ finnl report.doc 4 AN(JERSON CONSU~TINC{ ENGINEERS ANC. <br />