Huntington Lake is a reservoir in Fresno County, California on Big Creek, located in the Sierra Nevada at an elevation of 6,955 feet (2,120 m). The lake receives water from Southern California Edison's Big Creek Hydroelectric Project, as well as the many streams that flow into the lake. Some water leaving the lake flows to Big Creek, while some is diverted to nearby Shaver Lake. The lake is home to a variety of recreational activities, including camping, horse-back riding, skiing, sailing, fishing and more. It is drained and refilled through the Big Creek dam system each year, with winter water levels often dipping below 50 percent of the lake's capacity.

The Big Creek Hydroelectric Project is an extensive hydroelectric power scheme on the upper San Joaquin River system, in the Sierra Nevada of central California. The project is owned and operated by Southern California Edison (SCE). The use and reuse of the waters of the San Joaquin River, its South Fork, and the namesake of the project, Big Creek – over a vertical drop of 6,200 ft (1,900 m) – have over the years inspired a nickname, "The Hardest Working Water in the World".