A water line break that ripped a gaping hole in Coldwater Canyon Avenue Saturday, closing the street for at least a week, was the unavoidable result of failing to replace aging water pipes in the Valley, and similar breaks are bound to occur again, water officials warned Monday.
But Los Angeles Mayor Richard Riordan, apparently refusing to accept more such breaks as inevitable, fired off a letter to the Board of Water and Power Commissioners, asking that it investigate the cause of the break and “report to me immediately so we can avoid any further incidents.”
The 75-year-old water line that weakened and broke due to erosion was repaired early Monday when DWP workers replaced the burst section with eight feet of new pipe. But completing repairs to the street will keep Coldwater Canyon Avenue closed, between Mulholland Drive and Ventura Boulevard, to all traffic except local residents for at least a week, city transportation officials said.
DWP officials warned, however, that they expect similar breaks to occur elsewhere in the Valley as rust and erosion take their toll on about 200 miles of large trunk lines used to carry water into the city from the State Aqueduct near Sylmar, because the city has not been spending enough to replace them.
Most of the trunk lines are in the Valley, said Robert L. Simmons, assistant engineer in charge of the DWP’s water-operating division.
“We have an aging infrastructure--the pipes underground are not getting any younger,” Simmons said. “What we are doing is crossing our fingers and hoping that this kind of thing doesn’t happen again.”
Simmons said the city has no program to upgrade the trunk lines, such as the five-foot diameter line that broke on Coldwater Canyon Avenue, because the price of tearing up hundreds of miles of city streets to replace the pipes would be astronomical.
He added, however, that the city spends about $1.5 million annually to upgrade the city’s smaller water lines that carry water supplies from the trunk lines to residences and businesses.
Although the trunk lines, which are between five feet and 3 1/2 feet in diameter, are the “backbone of the system,” they are only replaced on a piecemeal basis when they rupture, Simmons said.
The water break Saturday spewed between 5,000 and 10,000 gallons of water per minute, boring a crater 30 feet wide and up to 20 feet deep. A break in an adjacent gas line forced fire officials to evacuate 24 residences in the upper-middle income neighborhood of Studio City.
The accident reminded officials of a similar incident in 1991 when a three-foot water pipe burst under Ventura Boulevard in Sherman Oaks, sending a current of water down the street and into some stores.
More than $1 million in claims were filed against the city over businesses, cars and apartments damaged during the 1991 accident. More than $500,000 in damages has been paid and several cases are still pending.
On Monday, DWP representatives went door-to-door to the residences in the area hardest hit by the flood, passing out instructions on how to file claims.
Although Harvey Lutske, chief claims agent for the DWP, said no one had yet filed a claim, he estimated that up to 100 may eventually be filed, mostly for waterlogged lawns and other minor damage.
Lutske, who along with the city attorney must approve claims before they are paid by the city, said the city would pay for all documented damage.
“If they can prove their loss, we’ll pay,” he said. “It’s only fair if they sustained damage and we’re responsible.”
He said reported cases of flooding were limited to a couple of inches of water.
“There is some (damage),” Lutske said. “But this is not the Mississippi River, like this past summer.”
He said although he expected the bulk of claims to come from residential property owners, there would probably be some claims filed by businesses that lost customers during the closure of Ventura and Laurel Canyon boulevards for several hours Saturday.
DWP workers Monday poured tons of slurry--a mixture of gravel and cement--to shore up the water-soaked soil around the site of the water break. The break also ruptured a smaller water line, a sewer line and the gas line.
DWP officials said all water, gas and sewer services were shut off immediately after the break but have since been repaired.
Coldwater Canyon Avenue is often used by commuters traveling between the Valley and the Westside as an alternate to the San Diego Freeway, carrying 27,000 to 30,000 vehicles a day.
Los Angeles Department of Transportation officials said they hope to reopen at least one lane on Coldwater Canyon Avenue within a week, but cannot predict a date. The lane would alternate between northbound and southbound traffic to accommodate the commuting patterns from the Valley to the Westside.
Immediately after the break, transportation officials closed Coldwater Canyon Avenue between Ventura Boulevard and Halkirk Street, prompting commuters to skirt around the closure through adjacent surface streets.
The resulting traffic increase on adjacent streets irked Studio City residents who awoke Monday to find a slow-moving parade of cars on their narrow, usually quiet streets.
Jeff Stuart, a 10-year resident of Alcove Avenue, watched in frustration Monday as a procession of cars lined his street, with some impatient drivers honking to move ahead.
Stuart suggested that the city assign a traffic officer to the intersection of Alcove Avenue and Ventura Boulevard so traffic will flow out of his neighborhood quicker.
“We could use a human being at the end of the street,” he said.
But Stuart said he was most annoyed by the constant buzzing of broadcast news traffic helicopters hovering over his house to report on the congestion.
“This is a bigger problem,” he said, gesturing to a circling helicopter.
Times correspondent Scott Glover contributed to this story.