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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 />it consists of an earthfill structure founded on bedrock along Little Fountain Creek. <br />The dam is about 350 feet long and approximately 32 feet high with a crest width of <br />approximately 13 feet. The dam crest is situated at elevation 6433.5, according to <br />GMS survey data. The upstream slope of the dam is lined with riprap that has been <br />overgrown by brush and trees. The upstream slope of the dam varies from 2.6 to <br />3.2 : 1.0 (horizontal:vertical). The downstream slope varies from 2.1 to 2.5 : 1.0. <br />The reservoir had an original storage capacity of approximately 20 acre-feet, but a <br />substantial amount of this storage volume has been displaced by sand and gravel that <br />washed into the reservoir during heavy rainstorms. Fountain and Fort Carson have <br />dredged sand and gravel at least twice in the past in order to maintain the reservoir <br />capacity. Water is released for use by Fountain and Fort Carson through a 12-inch <br />outlet works pipeline, constructed in about 1935, controlled by a gate valve. <br /> <br />The dam has two spillways. The service spillway at the north abutment has a <br />width of approximately eight feet and is lined with grouted riprap. The emergency <br />spillway at the south side of the dam is approximately 30 feet wide. The upper <br />portion of the emergency spillway is concrete-lined, but the lower portion does not <br />have any erosion protection. The lower portion has eroded over the years to bedrock <br />at several locations, which is a sandstone bed, "approximately 10 to 15 feet thick <br />and composed of course-grained, moderately well cemented sand and gravel," <br />according a preliminary geologic reconnaissance conducted by Kumar and Associates. <br />The eroded channel is presently threatening to undermine the access road along the <br />south side of the valley. This spillway may have been added some years after the <br />dam was constructed. To our knowledge, there has been no major maintenance or <br />rehabilitation work at the dam since its construction in the 1930's except for removal <br />of sand and gravel from the reservoir and minor maintenance such as brush removal, <br />etc. Roughly, 6,000 cubic yards of sand and gravel have accumulated in the <br />reservoir. <br /> <br />The construction drawings dating from 1935 indicate that the dam includes <br />one or two cutoff walls that are founded on bedrock. The drawings, however, <br /> <br />19 <br />