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Show existing canals. No serious disruption of the environment would be expected. Tyzack Aqueduct would traverse a ridge and would leave, construction scars which would not be expected to be completely restored on the steep north side. As the aqueduct leaves Brush Creek scars would be left. There would be very little spoil to be disposed of in conjunction with this Unit. Transmission lines would cause visual impact and landscape scarring which would remain visible for many years. The Unit drains would be principally buried pipelines with some open drains used as outlet channels. They would be installed through irrigated ground. Adverse impacts would be expected to be minor. Esthetics would be altered in the largely undeveloped area where the reservoir and aqueduct would be built, and much of its isolated atmosphere would be lost. Depletion of the Colorado River as a result of this Unit would be about 15,000 acre- feet per year. The increase in salt concentration at Hoover Dam would be 1 mg/ 1. Using the EPA economic analyses, this increase would cost downstream water users $ 41,400 per year in decreased yields. c. Upalco Unit148 ( 1) Description The Upalco Unit, which would supply an average annual amount of 20,500 acre- feet of water for supplemental irrigation to 42,610 acres of land, is scheduled for construction in the latter part of 1974. Major features of the Unit would include the Taskeech Dam and Reservoir and the Taskeech Feeder and Service Canals. A sketch map of the Unit and these features is found on Figure C- 21. Taskeech Reservoir would be formed by a dam constructed on the Lake Fork River approximately 6 miles downstream from the existing Moon Lake Dam. The reservoir site would be in the lower slopes of the Uinta Mountains. At normal water level the reservoir would inundate about 1,225 acres, which would include trees and willows along the stream, and grass and brush along the floor of the valley and up the slopes of the reservoir basin. Water to fill the reservoir would be obtained from Lake Fork and Yellowstone Rivers. The water from Yellowstone 415 |
