Union Valley Reservoir
Encyclopedia
Union Valley Reservoir is a reservoir
in eastern El Dorado County, California
, about 20 miles (32.2 km) northeast of Placerville
. The 277000 acre.ft lake is in El Dorado National Forest in the Sierra Nevada at an elevation of 4870 feet (1,484.4 m). It was formed in 1963 by the 453 feet (138.1 m) high earth and rockfill Union Valley Dam
on Silver Creek, which is a tributary of the American River
. The reservoir is owned by the Sacramento Municipal Utility District, a public electric utility, which operates the dam and many other dams in the area. Recreation such as boating
, fishing
and camping
is available there.
It stores snow melt runoff during the spring and releases it during the summer when electrical demand is greatest to a chain of hydroelectric power plants downstream. Union Valley Powerhouse at the base of the dam has a capacity of 46.7 MW and is operated as a peaking power plant
, supplying electricity during times of the greatest demand. Consumptive rights to the water itself are held by the City of Sacramento, California
.
The reservoir is fed by Big Silver Creek, Jones Fork Silver Creek, Tells Creek, Wench Creek and the outflows of Robbs Peak and Jones Fork powerhouses
. Jones Fork Powerhouse is not on Jones Fork Silver Creek but instead conveys water from Ice House Reservoir. Robbs Peak Powerhouse gets its water from the Middle Fork American River headwaters, by way of Loon Lake Reservoir
, and small reservoirs on Gerle Creek and South Fork Rubicon River. Downstream from Union Valley Dam, Silver Creek waters are largely diverted through two additional powerhouses below small reservoirs before joining the South Fork American River a few miles north of Pollock Pines, California
. Silver Creek was an intermittent creek before the development of Union Valley Reservoir and the diversions from the Middle Fork American River.
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...
in eastern El Dorado County, California
El Dorado County, California
El Dorado County is a county located in the historic Gold Country in the Sierra Nevada Mountains and foothills of the U.S. state of California. The 2010 population was 181,058. The El Dorado county seat is in Placerville....
, about 20 miles (32.2 km) northeast of Placerville
Placerville, California
Placerville is the county seat of El Dorado County, California. The population was 10,389 at the 2010 census, up from 9,610 at the 2000 census. It is part of the Sacramento–Arden-Arcade–Roseville Metropolitan Statistical Area.-Geography:...
. The 277000 acre.ft lake is in El Dorado National Forest in the Sierra Nevada at an elevation of 4870 feet (1,484.4 m). It was formed in 1963 by the 453 feet (138.1 m) high earth and rockfill Union Valley Dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
on Silver Creek, which is a tributary of the American River
American River
The American River is a California watercourse noted as the site of Sutter's Mill, northwest of Placerville, California, where gold was found in 1848, leading to the California Gold Rush...
. The reservoir is owned by the Sacramento Municipal Utility District, a public electric utility, which operates the dam and many other dams in the area. Recreation such as boating
Boating
Boating is the leisurely activity of travelling by boat, or the recreational use of a boat whether powerboats, sailboats, or man-powered vessels , focused on the travel itself, as well as sports activities, such as fishing or water skiing...
, fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....
and camping
Camping
Camping is an outdoor recreational activity. The participants leave urban areas, their home region, or civilization and enjoy nature while spending one or several nights outdoors, usually at a campsite. Camping may involve the use of a tent, caravan, motorhome, cabin, a primitive structure, or no...
is available there.
It stores snow melt runoff during the spring and releases it during the summer when electrical demand is greatest to a chain of hydroelectric power plants downstream. Union Valley Powerhouse at the base of the dam has a capacity of 46.7 MW and is operated as a peaking power plant
Peaking power plant
Peaking power plants, also known as peaker plants, and occasionally just "peakers," are power plants that generally run only when there is a high demand, known as peak demand, for electricity.-Peak hours:...
, supplying electricity during times of the greatest demand. Consumptive rights to the water itself are held by the City of Sacramento, California
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
.
The reservoir is fed by Big Silver Creek, Jones Fork Silver Creek, Tells Creek, Wench Creek and the outflows of Robbs Peak and Jones Fork powerhouses
Power station
A power station is an industrial facility for the generation of electric energy....
. Jones Fork Powerhouse is not on Jones Fork Silver Creek but instead conveys water from Ice House Reservoir. Robbs Peak Powerhouse gets its water from the Middle Fork American River headwaters, by way of Loon Lake Reservoir
Loon Lake (California)
Loon Lake Reservoir is a reservoir in the El Dorado National Forest of El Dorado County, California, United States. The lake is formed by Loon Lake Dam, completed in 1963 by Sacramento Municipal Utility District to conserve spring snow melt runoff for use during the summer and autumn for...
, and small reservoirs on Gerle Creek and South Fork Rubicon River. Downstream from Union Valley Dam, Silver Creek waters are largely diverted through two additional powerhouses below small reservoirs before joining the South Fork American River a few miles north of Pollock Pines, California
Pollock Pines, California
Pollock Pines is a census-designated place in El Dorado County, California, United States. It is part of the Sacramento–Arden-Arcade–Roseville Metropolitan Statistical Area...
. Silver Creek was an intermittent creek before the development of Union Valley Reservoir and the diversions from the Middle Fork American River.