Before wind, the sun and fossil fuels, there was water to generate electricity. And one of the largest hydroelectric plants in the country is Big Creek, located in California’s Sierra Nevada Mountains.

The historic plant recently turned 100 years and Southern California Edison (SCE) employees, retirees and the community gathered at Big Creek to not only celebrate the facility’s history, but to recognize those who continue to help produce and deliver clean, reliable energy to Californians.

The Big Creek system was America’s first large-scale integrated hydroelectric project. In addition to generating enough electricity to power approximately 650,000 homes, Big Creek’s contribution to the San Joaquin Valley community includes providing flood control, irrigation, recreation and environmental preservation.

The Big Creek project was conceived by John Eastwood, an engineer in the 1880s. Eastwood surveyed the San Joaquin River region of the Sierra Nevada Mountains, convinced that the abundant and steeply falling mountain streams could generate large amounts of electricity.

Ron Litzinger, SCE president, told the participants who attended the centennial event that Big Creek represents more than 1,000 megawatts of hydroelectric generation.

“What started in the imagination of one person has become a historical marvel, and has helped power the lives of countless Edison customers,” he said.

The impetus for building Big Creek came from California industrialist Henry Huntington, who financed and brought it to completion to power his Los Angeles Red Car trolley system and also the city’s burgeoning power demands in the early 20th century.

Construction of Big Creek started in 1910, with power reaching Southern California in 1913. But it wasn’t until 1917 that SCE acquired Big Creek and ran with Eastwood’s ambitious vision to build it into what it is today: one of the most important hydroelectric facilities in the country.

“It was one of the largest construction projects of its time, using the labor of thousands of people and unprecedented achievements in design, engineering and dam building for the 241-mile-long transmission line to Los Angeles,” said William Delain, SCE region manager in the San Joaquin Valley.

The Big Creek system draws from a watershed of 1,200 square miles in the Sierra Mountains, about 250 miles north of Los Angeles. The system includes nine power houses, 23 generating units, six major reservoirs and 27 dams that help generate 1,000 megawatts of cost-effective, renewable and environmentally sustainable hydro power that SCE delivers into the California power grid. The reservoirs can store more than 560,000 acre-feet of water.

The same water passes through multiple turbines that run numerous electric generators. From start to finish, water flowing through the Big Creek system travels more than 50 miles and falls 6,637 feet.

“The entire Big Creek system uses gravity to generate power,” said Delain. “We call Big Creek the ‘hardest working water in the world.’”