Sunset Boulevard reopens after water-main break

Sunset Boulevard reopened early Monday morning when crews finished repaving the thoroughfare after a water-main break created a massive sinkhole and flooded structures at the adjacent UCLA campus, the mayor’s office said.

Mayor Eric Garcetti’s office confirmed Sunset had reopened in time for Monday’s rush hour, but noted that drivers will be required to travel at reduced speeds on the affected part of the street.

Sunset near UCLA will close during overnight hours on Friday and Saturday as crews continue final repairs, officials said.

The break, which occurred at the juncture of two trunk lines running underneath Sunset, spilled 20 million gallons of water.

The surging stream, which shot upward for hours, created a 25-by-30-foot oval sinkhole about seven feet deep, said Joe Ramallo, spokesman for the Los Angeles Department of Water and Power.

Repairing the water main required more excavation. DWP crews used about 400 tons of sand and 540 tons of crushed aggregate to fill the hole.

Work crews also have been busy at UCLA, which sustained widespread damage. The water stranded about 960 cars in two parking structures and flooded the floor of Pauley Pavilion, the school’s storied basketball arena.

According to a statement from the mayor’s office, the arena will be ready for the UCLA men’s and women’s basketball seasons.

The lower garage levels were submerged to the ceiling in water. No one was injured because the garages filled up gradually, and a water-rescue team was quickly on the scene, helping several people to safety, said UCLA spokesman Tod M. Tamberg.

Most vehicles were parked above the flooding and simply had to await retrieval with owners.

But 400 were on floors that flooded. Owners can inspect and possibly retrieve them Tuesday at a lot adjacent to Jackie Robinson Stadium.

Even among these, said Tamberg, “there could be cars with water that went halfway up the wheel. The owners may be able to drive those off, and if they do that will be terrific. For others, it will be a tough day emotionally to see their car ruined.”

The college has begun “crowdfunding” aimed at raising $1 million to help with repair work and victim assistance. By Sunday it had raised more than $42,000.

Water was not fully pumped out till late Friday night, and then crews had to deal with mud and debris.

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, the DWP spokesman, 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, and containing the main flow took about 51/2 hours, according to the utility.

After the main leak was stopped, shutting off more than 90% of the flow, about 1,000 gallons per minute poured out for a day. Some, if not most, of that discharge was unavoidable, Ramallo said.

“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, then of nine valves in the area.

“We also had to maintain positive flow and pressure through the pipes to maintain water quality,” Ramallo said. 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 cause further leaks and breaks.

“The complexity of this job cannot be overstated,” Ramallo said.

The DWP has tentatively assumed responsibility for at least some of the damage, making claim forms available online at https://www.ladwp.com/claims. They can be emailed to claims@ladwp.com or mailed to 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 will return Monday.

howard.blume@latimes.com

Twitter: @howardblume