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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />Borrow Areas <br /> <br />The soils encountered In borings in the proposed borrow areas are <br />predominantly clay and weathered shale. These materials are highly <br />impermeable and would be excellent for construction of a dam and they are <br />present in sufficient quantity to construct the proposed dam. These materials <br />could be excavated to approximately fifteen feet below existing grade. <br /> <br />Slope Stability <br /> <br />Slope stability analyses were conducted for the dam cross-section shown in <br />Figure 4 using soil properties determined from the testing of the materials <br />sampled from the proposed reservoir location. The slopes shown on the typical <br />cross-section meet the State's stability requirements for dam safety. Complete <br />results of the stability analyses are in the Geotechnical Report in Appendix C,. <br /> <br />Summary <br /> <br />Based on subsurface investigation, testing, and analysis, the site appears <br />suitable for the construction of the proposed reservoir. Sound, highly <br />impermeable foundation materials were encountered at relatively shallow depths <br />at the location of the proposed dam and suitable clay borrow materials are <br />available in sufficient quantity for construction of the dam. A complete report of <br />the geotechnical investigation is contained in Appendix C. <br /> <br />Geologic Evaluation <br /> <br />A geologic assessment was made for the Dry Creek Reservoir site. The site <br />appears to be geologically simple and straightforward, based on a map study and <br />limited field investigations, with no lithologies, geologic structures or other <br />physical features that would complicate the construction of a dam. The <br />lithologies present would likely be relatively impermeable, and should provide <br />adequate dam construction material. <br /> <br />More specific geologic information is contained in Appendix D. <br /> <br />Mineral Resources <br /> <br />Northeastern Colorado contains various economical mineral resources including <br />petroleum, natural gas, uranium, gravel and crushed-rock aggregate, and <br />limestone. Gravel and crushed-rock aggregates are currently mined from various <br />localities in Northern Colorado, but only small amounts exist on this site. <br />Limestone can be mined from the Niobrara Formation. This formation exists on <br />the site, but no mining is conducted there currently. Uranium deposits are <br />known to exist in the Fox Hill Sandstone and Laramie Formations in Larimer <br />County. Currently there are no mineral resources being extracted from this site <br /> <br />Dry Creek Reservoir Feasibility Study <br /> <br />12 <br />