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<br />nr:3,~ <br />'-; w . <br /> <br />. <br /> <br />6. poor Site for Dam Construction <br /> <br />Approximately four miles south of the present location of the South <br /> <br />Platte River at the proposed Narrows Dam Site is an old ancestral river <br /> <br />valley. This channel was cut in bedrock known as Pierre shale, thousands <br /> <br />of years ago. The general direction of this bedrock is to the east. The <br /> <br />indications of this ancestral river were discovered when the area was <br /> <br />drilled for irrigation wells. Later there were exploratory holes drilled <br /> <br />to prove it. The horizontal distance between the two channels is variable <br /> <br />up to four miles. Starting at the railroad at Hardin, the old river bed <br /> <br />appears to be alon~ the north wall of the valley, then eastwardly to just <br /> <br />north of Empire Reservoir, then near the south end of Bijou #2 and continues <br /> <br />on to the south side to near Julesburg. At Fort Morgan the two come as <br /> <br />. <br /> <br />close as one mile. The river at the Narrows has erroded into the bedrock <br /> <br />some twenty plus feet. The bedrock channel to the south is filled with <br /> <br />up to 250 feet of sand and coarse gravel. <br /> <br />There is a negative vertical slope to the south of approximately <br /> <br />75 feet. This difference in elevation is from the bottom of the South <br /> <br />Platte River at the Narrows to the floor of the old channel. These <br /> <br />measurements are made from bedrock. This overburden is primarily river <br /> <br />sand and gravel with some dune sand on top in places. This deep bedrock <br /> <br />depression is an excellent aquafier for water. <br /> <br />The lakes of Empire and Bijou 12, along with the irrigation ditches <br /> <br />in this area, have a very high seepage loss. This stands to reason as <br /> <br />they are located very near or are on top of this old river bed filled <br /> <br />t <br />