West Fork Carson River offers the best opportunity for power development in the Carson River basin. The Hope Valley reservoir site could be developed to provide adequate storage regulation and concentration of fall would permit utilization of 1,400 feet of head in 51h miles below the clam site, or 1,900 feet of head in about 972 miles below the dam site; however, the average annual runoff susceptible of development is only about 70,000 acre-feet which limits the power that could be developed continuously in an average year with regulation to about 8,700 kilowatts utilizing 1,400 feet of head, or 12,000 kilowatts utilizing 1,900 feet of head. The method and degree of development will be determined to large extent by the method devised to supplement regulated flows from the Hope Valley reservoir to supply the water already appropriated for irrigation. If the Hope Valley site and the Watasheamu site on East Fork Carson River were developed coordinately water could be transferred to the West Fork for distribution through canals leading from that stream thus satisfying the deficiency due to regulation at Hope Valley and release of stored water on a power schedule. This would permit utilization of the entire 1,900 feet of fall.
Independent development of the West Fork for optimum power production would require re-regulation of releases from Hope Valley reservoir and storage of a considerable part of the fall and winter flow for use during the irrigation season. Adequate storage capacity is apparently not available on the West Fork below Hope Valley; but offstream storage may be available in Diamond Valley which could be utilized by diversion from the West Fork near Woodfords. This would limit the utilization of the stream for power purposes to the development of the 1,400 feet of head between the Hope Valley dam site and Wood fords. In a year of average discharge East Fork Carson River and three of its principal tributaries could be developed to produce about 13,500 kilowatts of firm power upstream of the Watasheamu site, which has been proposed as the location of a storage reservoir, the principal use of which would be for irrigation and flood control purposes. Substantial storage regulation would be required because of the seasonal variation in flow; and while sufficient storage capacity is available for such regulation, its value for power development is limited because of the lack of concentration of fall below the storage sites where head could be economically developed.
The Watasheamu reservoir with a powerplant near the Horseshoe: Bend site could be operated to develop about 5,400 kilowatts of continuous power in a year of average discharge; however, priority to use of water for irrigation purposes would undoubtedly require operation of the Watasheamu reservoir on a schedule unfavorable to the production of firm power. It is estimated that 47 million kilowatt-hours represents the maximum generation capability of a plant at the Horseshoe Bend site in year of average discharge and a large proportion of this amount would be generated during the period of peak irrigation demand and would be seasonal in nature. Installation of about 7,000 kilowatts of capacity in a plant at the Horseshoe Bend site appears feasible. Annual energy generation would probably be less than the maximum represented by streamflow, depending on the magnitude of releases from the Watasheamu reservoir for irrigation and the demand for seasonal power.
It is judged, from a general consideration of the probable cost of the required Structures in relation to the benefits which would accrue from the power that could be produced, that development of East and West Forks Carson River for power purposes only would not be feasible.
Additional publication details
USGS Numbered Series
Water-power resources in upper Carson River basin, California-Nevada, A discussion of potential development of power and reservoir sites on east and west forks, Carson River