Power Loss, Earlier Break Blamed for Burst Pipe

A power outage and an earlier break in the line were blamed Sunday for causing a 66-inch water main to burst, temporarily turning one of the city’s busiest roadways into a free-flowing river.

Calleguas Municipal Water District officials said it will probably take two weeks to replace a 20-foot section of the water main that severely damaged Madera Road just north of Royal Avenue.

District officials also expressed concern Sunday that another break in the line could occur if there are additional power outages while the repair work is being done. An outage would increase water pressure on the main line because several of Calleguas’ purveyors would not be able to pump water out, officials said.

“We’re vulnerable right now,” said Donald Kendall, general manager for the water district. “If another outage occurs, we could be in trouble.”

The water main’s 4-inch-thick concrete-and-steel pipe ruptured about 5 p.m. Saturday, spewing about 8 million gallons of water along Madera Road before it was finally shut off 1 1/2 hours later.

Although dozens of people were temporarily evacuated from their homes and businesses, only one apartment unit was damaged. About 50 residences in Moorpark lost water service for about eight hours. No injuries were reported.

The broken main left a massive hole in the southbound lanes of Madera, measuring 30 feet long, 12 feet wide and 10 feet deep. A half-mile section of the roadway was shut down, but the northbound lanes were reopened Sunday evening to traffic in both directions.

“We want to get things back in operation as quick as we can,” said Simi Valley Mayor Greg Stratton, who spent part of the morning inspecting the site. Still, Stratton advised motorists to find an alternate route to work if possible while the roadway is being repaired.

The mayor said he was pleased that no one was hurt when the line burst, hurling 2- and 3-foot chunks of asphalt through the air and leaving a gaping hole in the roadway large enough to swallow several cars.

“We’re fortunate that it happened when it did,” Stratton said. “If this had occurred at 5 o’clock on a Monday afternoon, it may have taken a car with it.”

As for the cause of the water main break, Kendall said Calleguas officials traced the source to two separate events, the first of which occurred Wednesday morning.

That is when a construction contractor working for a Wood Ranch developer accidentally cracked the water line while taking soil samples, he said.

A section of the line was shut down for repairs and was about 15 minutes away from being reopened Saturday when a power outage occurred on the city’s west end, Kendall said. The brief power failure knocked out pumping stations that transfer water from the main line to several of Calleguas’ purveyors.

At the time, about 20,000 gallons of water per minute were flowing through the main--an especially high volume attributed to the day’s warm temperatures, Kendall said. When the outage occurred, he said, it caused a huge surge in the main line.

With nowhere for the water to go, the line burst.

“It was like driving your car through a brick wall at 100 mph,” Kendall said.

Although there were no preliminary damage estimates Saturday, Kendall said repair costs for the pipeline and roadway would be “in the six figures.” He said that Calleguas and its insurance company would probably pick up the cost for the break.

Kendall added that Calleguas will be working closely with Southern California Edison officials over the next two weeks to do everything possible to avert another power failure.