Wishon Dam (National ID # CA00411) is a dam in

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 ...

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. It impounds the

North Fork Kings River The North Fork Kings River is a tributary of the Kings River, in the U.S. state of California. The river's main stem is entirely within Fresno County, and its watershed drains about of the southern Sierra Nevada mountain range. Course It ri ...

to form Wishon Reservoir. The earthen and rockfill gravity dam was constructed in 1958 by

Pacific Gas and Electric Company 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 ...

(PG&E) with a height of 260 feet and a length of 3,330 feet at its crest.Federal Register, Volume 60 Issue 112 (Monday, June 12, 1995)
/ref> Wishon Dam and its companion Courtright Dam, which stands about five miles to the north, along with other smaller auxiliary gravity dam structures, are elements of PG&E's Haas-Kings River Project. Courtright Reservoir serves 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 is the lower. 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 ...

, which is also when it is most expensive, water is drained from Courtright Reservoir, run through the 1,212 MW Helms Power Plant and emptied 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. The reservoir Wishon Dam creates, Wishon Reservoir, has a maximum capacity of 128,606

acre-feet The acre-foot is a non- SI unit of volume equal to about commonly used in the United States in reference to large-scale water resources, such as reservoirs, aqueducts, canals, sewer flow capacity, irrigation water, and river flows. An acre-f ...

. PG&E maintains Lily Pad Campground with 15 campsites on the southern shore, and recreation includes fishing (for German brown, rainbow or Eastern Brook trout), boating, camping and hiking. The area north of the dam that is now covered by the reservoir was known as Coolidge Meadows prior to the construction of the dam.

References

{{authority control Dams in California Reservoirs in California Pacific Gas and Electric Company dams Buildings and structures in Fresno County, California Embankment dams Dams completed in 1958 Dams in the Tulare Basin Reservoirs in Fresno County, California Reservoirs in Northern California

See also

References