Courtright Reservoir
Encyclopedia
Courtright Reservoir is a reservoir
in Fresno County, California
. The reservoir is at an elevation of 8,170 feet (2,490 m) in the Sierra National Forest
, in the Sierra Nevada Mountain Range. The reservoir is formed by Courtright Dam on Helms Creek and has a capacity of 123300 acre.ft. The dam
is composed of rock-fill and is 315 feet (96 m) tall, measured from the crest to the original streambed. It was completed in 1958 and is owned by Pacific Gas and Electric. Its sole purpose is hydroelectricity
production.
In addition to conventional hydroelectricity production, Courtright Reservoir also serves as the upper reservoir in a pumped storage hydroelectric
system. Wishon Reservoir, a couple of miles downstream, is the lower reservoir. During times of peak demand for electricity
, which is also when it is most expensive, water is drained from Courtright Reservoir, run through the 1,212 MW Helms Power Plant and empties into Wishon Reservoir. When demand and prices for electricity are low, water is pumped from Wishon Reservoir to Courtright Reservoir using the power plant's reversible turbines. Interestingly Helms Power Plant is 1,000 feet (300 m) underground in a chamber carved out of solid granite
at the north end of Wishon Lake. It is similar to Southern California Edison
's Eastwood Powerhouse near Shaver Lake
, which is also a pumped-storage plant.
Courtright reservoir is a haven for weekend and outdoor enthusiasts seeking to camp, fish, hike, boat, swim, rock climb, and 4x4 among others. It is surrounded by unique domes of granite that are essentially in the center of the Sierra Batholith and are highly sought after by rock climbers from all around. It is also used during warmer-weather months by local astronomers, such as members of the Central Valley Astronomers, who take advantage of its excellent location for night sky viewing free from light and air pollution .
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 Fresno County, California
Fresno County, California
Fresno County is a county located in the Central Valley of the U.S. state of California, south of Stockton and north of Bakersfield. As of the 2010 census, it is the tenth most populous county in California with a population of 930,450, and the sixth largest in size with an area of . The county...
. The reservoir is at an elevation of 8,170 feet (2,490 m) in the Sierra National Forest
Sierra National Forest
Sierra National Forest is a U.S. National Forest located on the western slope of central Sierra Nevada in the state of California. The forest is known for its mountain scenery and natural resources. Forest headquarters are located in Clovis, California...
, in the Sierra Nevada Mountain Range. The reservoir is formed by Courtright Dam on Helms Creek and has a capacity of 123300 acre.ft. The 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...
is composed of rock-fill and is 315 feet (96 m) tall, measured from the crest to the original streambed. It was completed in 1958 and is owned by Pacific Gas and Electric. Its sole purpose is hydroelectricity
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
production.
In addition to conventional hydroelectricity production, Courtright Reservoir also serves as the upper reservoir in a pumped storage hydroelectric
Pumped-storage hydroelectricity
Pumped-storage hydroelectricity is a type of hydroelectric power generation used by some power plants for load balancing. The method stores energy in the form of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost off-peak electric power is used to run the pumps...
system. Wishon Reservoir, a couple of miles downstream, is the lower reservoir. During times of peak demand for electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
, which is also when it is most expensive, water is drained from Courtright Reservoir, run through the 1,212 MW Helms Power Plant and empties into Wishon Reservoir. When demand and prices for electricity are low, water is pumped from Wishon Reservoir to Courtright Reservoir using the power plant's reversible turbines. Interestingly Helms Power Plant is 1,000 feet (300 m) underground in a chamber carved out of solid granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
at the north end of Wishon Lake. It is similar to Southern California Edison
Southern California Edison
Southern California Edison , the largest subsidiary of Edison International , is the primary electricity supply company for much of Southern California, USA. It provides 14 million people with electricity...
's Eastwood Powerhouse near Shaver Lake
Shaver Lake
Shaver Lake is an artificial lake on Stevenson Creek, in the Sierra National Forest of Fresno County, California. At elevation , several smaller streams also flow into the lake and receives water from the underground tunnels of Southern California Edison's Big Creek hydroelectric project...
, which is also a pumped-storage plant.
Courtright reservoir is a haven for weekend and outdoor enthusiasts seeking to camp, fish, hike, boat, swim, rock climb, and 4x4 among others. It is surrounded by unique domes of granite that are essentially in the center of the Sierra Batholith and are highly sought after by rock climbers from all around. It is also used during warmer-weather months by local astronomers, such as members of the Central Valley Astronomers, who take advantage of its excellent location for night sky viewing free from light and air pollution .