Courtright Reservoir is a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

Fresno County, California Fresno County (), officially the County of Fresno, is a county located in the central portion of the U.S. state of California. As of the 2020 Census, the population was 1,008,654. The county seat is Fresno, the fifth-most populous city in Cali ...

. The reservoir is at an elevation of 8,170 feet (2,490 m) in the

Sierra National Forest Sierra National Forest is a U.S. national forest located on the western slope of central Sierra Nevada in Central California and bounded on the northwest by Yosemite National Park and the south by Kings Canyon National Park. The forest is kno ...

, in the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

Mountain Range, bordering the

John Muir Wilderness The John Muir Wilderness is a wilderness area that extends along the crest of the Sierra Nevada of California for , in the Inyo and Sierra National Forests. Established in 1964 by the Wilderness Act and named for naturalist John Muir, it encompa ...

and the Dinkey Lakes Wilderness. The high Sierra reservoir is formed by Courtright Dam in Helms Creek canyon and has a capacity of . The

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

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 The Pacific Gas and Electric Company (PG&E) is an American investor-owned utility (IOU). The company is headquartered in the Pacific Gas & Electric Building, in San Francisco, California. PG&E provides natural gas and electricity to 5.2 milli ...

. In 1984 the Helms Pumped Storage Powerhouse was added to the reservoir allowing it to pump water from Wishon to Courtright. Its primary purpose is

hydroelectricity Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewabl ...

production. The lake is an "off-river" (or "off-channel") storage reservoir. In addition to the small amount of conventional hydroelectricity production from the flow of Helms Creek, Courtright Reservoir serves mainly as the upper reservoir for the

Helms Pumped Storage Plant The Helms Pumped Storage Plant is located 50 mi (80 km) east of Fresno, California in the Sierra Nevada Mountain Range's Sierra National Forest. It is a power station that uses Helms Creek canyon on the North Fork of the Kings River for ...

. Wishon Reservoir, an on-channel reservoir a couple of miles downstream on the Kings River, is the lower reservoir and main water source. During times of peak demand for

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

, 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 A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid. Many pow ...

's reversible

turbines A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful Work (physics), work. The work produced by a turbine can be used ...

. Helms Power Plant is 1,000 feet (300 m) underground in a chamber carved out of solid

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...

at the north end of Wishon Lake. It is similar to

Southern California Edison Southern California Edison (or SCE Corp), the largest subsidiary of Edison International, is the primary electricity supply company for much of Southern California. It provides 15 million people with electricity across a service territory of app ...

's Eastwood Powerhouse near

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 it receives water from the tunnels of Southern California Edis ...

, 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 8,170 feet (2,490 m) elevation and excellent location for night sky viewing free from light and air pollution. As with many outdoor areas there are some animal transmittable diseases to be aware of.

Ticks Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...

in the area have been known infect people with the

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

that causes tick-borne relapsing fever. The

yellow-bellied marmot The yellow-bellied marmot (''Marmota flaviventris''), also known as the rock chuck, is a large, stout-bodied ground squirrel in the marmot genus. It is one of fourteen species of marmots, and is native to mountainous regions of southwestern Canad ...

is known to carry

cryptosporidium ''Cryptosporidium'', sometimes informally called crypto, is a genus of apicomplexan parasitic alveolates that can cause a respiratory and gastrointestinal illness (cryptosporidiosis) that primarily involves watery diarrhea (intestinal cryptosp ...

, which can be infectious to humans. Additionally due to the elevation and the thinner atmosphere there has been slightly higher but not dangerous levels of radiation recorded here.

References

External links

United States Forest Service
{{authority control Reservoirs in Fresno County, California Lakes of the Sierra Nevada (United States) Sierra National Forest Reservoirs in California Reservoirs in Northern California

See also

References

External links