Repaving of a damaged portion of Sunset Boulevard was scheduled to get underway Sunday afternoon five days after a water-main break damaged the thoroughfare and flooded structures at the adjacent UCLA campus.
Officials declined to say when the roadway would reopen.
The break, which occurred at or near the juncture of two trunk lines running underneath Sunset Boulevard, spilled 20 million gallons of water.
The flooding stranded about 960 cars in two parking structures and ruined the floor of Pauley Pavilion -- the school’s storied basketball arena.
The surging stream, which shot upward like a geyser for hours, created a 25-by-30-foot oval sinkhole about seven feet deep, said Joe Ramallo, communications director for the Los Angeles Department of Water and Power.
Repairing the water main required much more excavation. DWP crews used approximately 400 tons of sand and 540 tons of crushed aggregate to fill the hole.
The cause of the break is under investigation. The L.A. water system has many old underground lines that have been deteriorating.
“At this point, corrosion is suspected,” Ramallo said.
The utility endured heavy criticism from residents and city officials for the length of time needed to shut off the water. The incident began about 3:30 p.m. Tuesday; containing the main flow required about five and a half hours, according to the utility.
Even after the main leak was stopped, about 1,000 gallons per minute poured out for a day.
Ramallo said the smaller flow was about 2% to 5% of what had been flowing. And some, if not most, of that discharge was unavoidable, he added.
“One of the things that can happen when we shut down pipes too fast is that it can damage other pipes,” he said.
The shutdown involved the coordinated control first of three valves and then of nine valves in the area.
“We also had to maintain positive flow and pressure through the pipes to maintain water quality,” added Ramallo. Otherwise, Westside residents would have had to boil water to make sure it was safe.
Turning the tap on again also has risks because fluctuation in pressure in the surrounding area could result in further leaks and breaks.
“The complexity of this job cannot be overstated,” said Ramallo.
Los Angeles Department of Water and Power
Attn: Claims Section
P.O. Box 51111, Room 342
Los Angeles, CA 90051-0100
DWP had staff members at UCLA over the weekend to process claims from 8 a.m. to 7 p.m. adjacent to Parking Lot 36; the workers are to return Monday.