Water Pipeline Break May Affect 700,000

A major pipeline to south Orange County broke Monday in Irvine, affecting the water supplies of as many as 700,000 residents in 14 communities, officials said.

“We’re asking south Orange County residents to curtail landscape irrigation and reduce indoor water usage as much as possible,” said Karl Seckel, assistant general manager and principal engineer of the Municipal Water District of Orange County.

The break, on the Metropolitan Water District’s Allen-McColloch Pipeline near California 241 and Portola Parkway, could particularly affect residents of Mission Viejo and Rancho Santa Margarita, where a separate pipeline break Saturday had already lowered reservoir storage levels.

Water officials asked residents and businesses to begin conserving water immediately in Irvine, Los Alisos, Lake Forest, El Toro, Laguna Woods, Trabuco Canyon, Santiago Canyon, Mission Viejo, Santa Margarita, San Clemente, Laguna Beach, Laguna Niguel, Laguna Hills and Dana Point.

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 the southern part of the 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.

The pipeline break was discovered in a strawberry field east of Irvine, water officials said. Crews were dispatched and began repairs as water was rerouted through another pipeline to as many customers as possible.

“We have crews there assessing the repair work, and 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. “We’re estimating that repairs may take seven to 10 days, but we can’t be sure until we excavate the pipe and determine the extent of the damage.”

The 69-inch reinforced concrete pipeline was buried 25 feet below the surface in an undeveloped area, water officials said. Investigators were still trying to determine Monday night what caused the rupture, which blew pieces of concrete to the surface. No one was injured by the blast, officials said.

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.