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SAN JACINTO, Calif. () — Eyewitness News was given a rare look inside the engineering marvel, which was the largest public works project in Southern California during the Great Depression, while it’s shut down for its annual maintenance.
It’s the final leg of the massive Colorado River Aqueduct: the 13-mile-long San Jacinto tunnel, bringing up to 1,700 cubic feet of water per second underneath one of Southern California’s tallest mountains.
“When you come to constructing a tunnel like this, through 13 miles of granite rock that was leaking water as they were mining, it was certainly a challenge for those folks,” said John Bednarksi, the assistant general manager of water resources and technical services for the Metropolitan Water District of Southern California.
“To come into this facility and see something that our forefathers built almost 100 years ago; just seeing the sheer magnitude, it’s very impressive.”
Bednarski said what’s most incredible about the construction of the San Jacinto tunnel is that it was done entirely by hand, without the assistance of modern-day technology.
“A lot of the things we take for granted today as engineers, like being able to survey with remote equipment, drones and other types of technology, that wasn’t available back in the 1930s,” he said.
“So we literally had people, surveyors, going out on horseback trying to find the best way to find the best route for the aqueduct to come through the Mojave Desert.”
The Colorado River Aqueduct begins near Parker Dam and stretches 242 miles to the west. At the end of the San Jacinto tunnel the water can either continue toward Lake Mathews in Riverside or be diverted toward San Diego.
Bednarksi said he’s unaware of the aqueduct ever being shut down unexpectedly, in part because of annual maintenance done during the winter months.
The aqueduct is scheduled to be reactivated at the end of March.
“The longevity of the facility to reliably deliver water to Southern California is just outstanding,” he added.
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