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. . . CHAPrER III DESIGNS AND ESTIMATES Spillway The spillway would be an open concrete structure 1,075 feet long, buH t in the breccia bedrock of the right dam abutment. The structure would have an uncontrolled ogee overflow crest at elevation 8,440 feet, a long chute of rectangular section, and a bucket-type energy dissipater located about ;00 feet downstream from the toe of the dam. The interior width of the spillway would be 25 feet at the overflow crest but would be reduced to the 12.5-foot chute width in a short transition. A channel would be excavated to an elevation of 8,436 feet upstream from the inlet, and another channel would be excavated in the canyon bottom to convey spillway discharges from the bucket to Soap Creek. A concrete bridge would be constructed across the lower end of the spillwa;,< as part of the access road to the outlet tunnel. The spillway would have a discharge capacity of 2,090 second-feet at the maximum reservoir water surface elevation of 8,448.2 feet. The spillway, in combination with the surcharge storage in the reservoir, would be capable of protecting the dam against the design flood which has a peak of 7,330 second-feet and a 15-day volume of 29,000 acre-feet. Crystal Creek Diversion Dam The Crystal Creek Diversion Dam would be constructed on Crystal Creek for diversion of a maximum of 600 second-feet of water into Fruit- land Canal. The existing diversion dam for the Fruitland ditch located about a half mile upstream and the diversion works for the Cattlemens ditch still farther upstream would be abandoned. The new structure would consist of an uncontrolled ogee spillway, canal headworks, and a sluice- way, all of concrete construction, and a compacted earthfill dike on the left side of the spillway extending to higher ground. Mancos shale bed- rock and well graded stream gravels would provide the foundation for the structure. The spillway would have a crest length of 60 feet and is designed to pass 870 second-feet, the flood flow of 100-year frequency, at a maximum water surface elevation of 7,970 feet. A 4-foot by 4.foot slide gate with pedestal lift would control flows through a 5-foot sluice- way located to the right of the spillway. The canal beadworks would be located adjacent to the sluiceway and would consist of an intake structure, a trashrack, an inlet transition, a rectangular flume, and an outlet transition. Releases through the headworks would be regulated by two 10-foot by 9-foot radial gates oper- ated by an electric motor. The earth dilte would be about 880 feet long and would have a crest width of 15 feet at an elevation of 7,973 feet. An existing county road adjacent to the headworks would serve as a dike on the right side of the diversion structure. A concrete apron witb a steel sheet piling cutOff would be constructed on the upstream face of the concrete structures. Riprap protection would be prOVided on 19