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<br />BUREAU OF RECLAMATION REPORT <br /> <br />would be an earth-fill structure 180 feet in height above stream bed and <br />1,450 feet in length at the crest. It would be a rolled earth-fill struc- <br />ture with an upstream section of impervious material blanketed with a 3- . <br />foot layer of rock riprap and a downstream section of semi pervious material <br />also blanketed with rock. A 30-foot cut-off trench backfilled with imper~ <br />vi?us materials would extend across the stream bed and a concrete cut-off <br />wall would be constructed to bedrock in the abutments. Both the outlet <br />works and spillway would be located. in the right ab\ltment and would dis- <br />c~rge into a concrete stilling pool in the river bed. The outlet works <br />woUld be housed in a concrete-lined tunnel and would have a maXimum <br />capacity of 480 second-feet at normal water surface elevation ~,132 feet. <br />The spillway would be a concrete side channel with ~ discharge capacity <br />of 12,000 second-feet. A light-duty road in the Lenton Resei'1toir Basin <br />would be relocated as a part of dam construction. <br /> <br />water would be released from the reservoir as heeded and conveyed <br />in the natural river channel to heads of various downstream canals and <br />ditches that would divert the flow for distribution to project lands. <br />The largest diversion from the river would be made e.pproxima. tely 15 <br />miles below Lemon Dam where a concrete weir approximately 7 feet high <br />and 60 feet long would be constructed to turn water into the existing <br />Florida Farmers ditch. This ditch would be enlarged along the first <br />5.2 miles of its course to an initial capacity of 158 second-feet, <br />approximitely twice its present capacity. At the end of the enlarged <br />section, a special concrete turn-out would be installed to deliver part <br />of the water to the existing Florida Canal which passes under the ditch <br />at this point. Both the canal and the ditch would convey the water to <br />lands on Florida Mesa. The existing canal and lateral system would be <br />utilized to serve the presently irrigated lands on the mesa, and the <br />distribution systems would be enlarged and extended where necessary to <br />serve the new lands on the mesa. Small ditches also would be constructed <br />to serve the new lands in Florida River Valley, and minor drainage works <br />would be provided for about 650 acres in the valley. Fish screens would <br />be installed at the headings of the Florida Farmers ditch and Florida <br />Canal. Some Florida River channel improvement would also be made ti" <br />better conditions for fish. <br /> <br />Geologic studies, including exploration by test pitting and diamond <br />core drilling, indicated that the foundation at the Lemon site is compe~ <br />tent for support of the dam as designed and that the reservoir basin, <br />being underlain by iIIlpervious layers of shales and san:lstone, is well <br />suited for water storage. Materials near the dam site, including imper- <br />vious and semipervious earth material, rock, sand, and gravel, were also <br />found suitable for construction. Manufactured materials could be hauled <br />over gravelled road either from Durango or from the Florida railroad <br />siding, both about 16 miles from the site. <br /> <br />The plan discussed herein for storage at the Lemon site was selected <br />as the most desirable means of development in the area since it would pro- <br />vide more benefits for the costs involved than any of the several other <br />plans considered. Other plans studied in the investiga.tion included storage <br /> <br />3 <br />