Burst Pipe Closes Coldwater Canyon Ave. : Utilities: Water supply is threatened as crews work to repair crater 30 feet wide. Officials say it will be a week before normal traffic can be restored on Studio City street.

In spite of city workers laboring into the night to repair a 75-year-old ruptured underground pipe that threatened water supplies to hundreds of hillside residents, city officials say it will be a week until normal traffic can be restored on busy Coldwater Canyon Avenue.

The five-foot-wide pipe burst Saturday beneath Coldwater Canyon Avenue uncorking a geyser that flooded yards, dug a 30-foot-wide crater in the road and forced a shutdown of the busy traffic corridor.

City officials said the pipe, laid in 1918, ruptured because rust ate through its steel walls. They said the problem was an unavoidable consequence of the aging of Los Angeles’ vast underground web of water lines.

“There is going to be excavation there until Friday at least,” said Ed Freudenburg, a Department of Water and Power spokesman. An eight-inch temporary replacement line is expected to be installed today, but the crater created by the burst line will remain until midweek, Freudenburg said. Then it will take two more days to fill in the hole and resurface the street.

Freudenburg said city transportation officials were debating whether to close the road or create one-way rush-hour traffic lanes. But Councilman Zev Yaroslavsky, who toured the site Sunday, said that even with designated detours onto side streets, using the road at rush hour “would be impossible.” He also noted that continuing roadwork on nearby Laurel Canyon Boulevard has snarled traffic for hillside commuters.

Crews from the DPW brought in dump trucks, a bulldozer and a crane to repair the broken pipe, which funnels water from the state aqueduct near Sylmar to a 2.2-million-gallon storage tank at the top of Coldwater Canyon.

That tank regulates water pressure and delivery to hundreds of homes in the upscale precincts between Coldwater and Laurel canyons and Mulholland Drive and Sunset Boulevard. DWP officials said because of the rupture, the tank had dropped to one-third full.

Water service to hillside customers was not interrupted but officials worried that some could be without water or adequate water pressure as the tank level dropped.

“If that tank runs out of water, you’re going to have people without water and extremely low pressure, depending on where they are,” said Robert L. Simmons of the DWP’s water operating division.

Officials urged residents to open their faucets as little as possible until the pipe is fixed.

The spurting water from the ruptured line also damaged an adjacent gas pipeline, prompting a brief evacuation of about 75 residents on Coldwater Canyon Avenue just south of Ventura Boulevard.

Passersby gawked at the crater as residents pointed video cameras at hard-hatted DWP workers and tried to clean mud off their driveways.

John Moomjian, who lives across the street from the pipe break, sat on his front steps and recalled that the geyser Saturday “looked like Yellowstone National Park.”

Resident Pat Chaimowitz lost one end of her semicircular driveway to the crater, along with some rosebushes and other plants. She shook her head as DWP workers scurried through the neighborhood, testing water faucets.

“They keep turning it on and off,” she said. “I’m trying to do a wash here.”

The home of Chaimowitz’s next-door neighbor, Fred Alaee, absorbed most of the damage from the crater, which sliced away a large portion of his front yard. Chaimowitz said Alaee had retreated to a home in Beverly Hills.

The city is engaged in a large-scale program to reinforce smaller water pipes with concrete, but officials said it is economically impractical to check for leaks on large-diameter pipes such as the ruptured one, all of which would have to be dug up to be inspected.

“There’s no real way at all of predicting where the problem spots are going to be” in larger pipes, many of which are decades old, the DWP’s Simmons said.

He said such ruptures are likely to increase as the city’s water pipes continue to age.