S. County Pipeline Break Disrupts Water to 700,000

One of the two massive pipelines that carry water to south Orange County burst Monday, flinging concrete chunks into the air and curtailing the water supply to as many as 700,000 residents in 13 communities, officials said.

No one was injured by the rupture of the Metropolitan Water District’s Allen-McColloch Pipeline under a strawberry field near the Foothill Transportation Corridor and Portola Parkway, officials said.

The 69-inch reinforced concrete pipeline was buried 25 feet down.

“This is the largest leak I’ve ever witnessed and a little frightening,” said Bill Cooper, a manager for the Municipal Water District of Orange County and one of the first people on the scene. “This was a catastrophic failure. It appears that portions of the pipe were actually blown up into the surrounding hillside.”

Karl Seckel, assistant general manager and principal engineer of the water district, said, “We’re asking south Orange County residents to curtail landscape irrigation and reduce indoor water usage as much as possible.” He suggested that residents take shorter showers and delay washing cars or doing laundry.

The communities affected are Irvine, Lake Forest, El Toro, Laguna Woods, Trabuco Canyon, Santiago Canyon, Mission Viejo, Rancho Santa Margarita, San Clemente, Laguna Beach, Laguna Niguel, Laguna Hills and Dana Point.

Water will be redirected there from local reservoirs and other sources in Orange County, officials said, but without conservation efforts that supply would last only four to five days. Officials estimate that repairing the leak will take seven to 10 days.

A crew of about two dozen worked under lights and used earthmoving equipment through the night Monday to dig to the rupture, hoping to reach it by morning. The damaged portion of the pipeline then will be removed and taken to a water district facility in La Verne to be repaired or replaced.

Officials also want to find out what caused the break. Erosion, faulty construction or recent earthquakes may have been a factor, water officials said.

The break could particularly affect residents of Mission Viejo and Rancho Santa Margarita, where a separate pipeline break Saturday already had lowered reservoir levels. That rupture appeared to be unrelated to Monday’s incident, officials said.

The pipeline, built by the Municipal Water District of Orange County and dedicated in 1981, is 26 miles long and runs from Yorba Linda to South County. It was carrying treated water from the Colorado River and Northern California on Monday morning when system operators near Pasadena noticed that its flow had decreased.

Repair crews were dispatched immediately and began repairs as water was rerouted through another pipeline to as many customers as possible.

“We have contacted our south Orange County customers to determine their supply situation,” said Eddie Rigdon, assistant manager of Metropolitan’s water system operations group.

Metropolitan’s regional system control center spotted trouble on the pipeline about 9 a.m. The break was located and sections on either side of the break shut down by about 2 p.m., officials said. Mud had covered a section of nearby Portola Parkway. Orange County sheriff’s deputies directed traffic while the road was cleared.

Rigdon said the flooded hole will have to be pumped out before the pipeline can be uncovered and inspected to determine the length of pipe that must be replaced.

Times wire services also contributed to this report.