Los Angeles Department of Water and Power crews Wednesday evening began pouring asphalt over the sinkhole caused by a water-main rupture that flooded a swath of West Hollywood.
The crews had to wait until completion of the 24-hour curing process for the slurry poured into the Sunset Boulevard sinkhole Tuesday, according to the DWP. The department hopes to reopen the heavily traveled roadway Thursday night or Friday morning.
DWP officials said that since the 36-inch water main ruptured last Thursday, repair crews “have performed complex work including pumping, repairing the 36-inch riveted steel pipe, welding the pipe, repressurizing and ensuring there are no leaks, flushing, disinfecting and water quality testing.”
The DWP water quality team is preparing to conduct water quality testing to ensure all standards are met before the repaired 36-inch pipe is returned to service. The new section of the pipe has been disinfected and is now filled with water that is being isolated and held in preparation for water quality testing.
Once test results confirm the water inside the repaired section of the pipe meets water quality standards, the trunk line can be returned to service as early as Friday, according to the DWP.
On Wednesday, crews used chlorine “to treat the pipe and ensure it is free of any bacteria,” according to the DWP.
“LADWP continues to assure customers that water remains safe to drink and there are no service interruptions expected as this work approaches completion,” the utility stated. “Customers are still urged to conserve water to help avoid low-pressure periods during high demand.”
Sunset Boulevard remains closed between Sherbourne Drive and San Vicente Boulevard, with limited local access on nearby streets including Cynthia and San Vicente, as repairs continue.
Work on repairing the broken main, which dates to 1916, involved more than 250 LADWP workers toiling around the clock after the rupture that was reported at about 3 a.m. Thursday on Sunset Boulevard at Holloway Drive. Roughly 17 million gallons of water poured out of the pipe and flowed down West Hollywood streets, pushing around cars and flooding garages while shifting massive chunks of asphalt and concrete slabs.
By 7 a.m. last Thursday, the rushing water, which sent debris downhill to Santa Monica Boulevard, had been stopped.
Repairs of the broken main were completed Sunday night as a new 25-foot section was welded into place.
The LADWP was working with the Metropolitan Water District of Southern California, Los Angeles County Public Works and other utilities to protect underground infrastructure during the repairs.
Some businesses in the area remain closed, and many residents suffered property damage in the disaster.
Customers with questions regarding the pipe rupture may call 1-800-DIAL-DWP. Claims information is available at LADWP.com/Claims.
West Hollywood has launched a website with regularly updated information about the response and recovery effort. The site, weho.org/watermainbreak, includes repair updates, street closures, traffic information, Metro detours, parking enforcement changes, claims information, hotel discounts for affected residents and other resources.
Officials said the 10-mile Sunset Trunk Line that ruptured had already been designated for replacement. The department said design work is underway on a project to replace nearly 6.4 miles of large-diameter pipeline and 3.5 miles of distribution pipe, with construction expected to begin in 2031.
The utility said it replaced more than 246,000 feet of water pipeline during 2024 and 2025 and is on track to replace another 246,000 feet this year. The department also said its leak rate is 36% below the national average, averaging 16.1 leaks per 100 miles of pipe compared with 25 leaks per 100 miles nationwide.
The specific cause of the break was under investigation, but Anselmo Collins, the LADWP’s chief operating officer and senior assistant general manager of the water system, said pressure in water delivery lines is highest at night when demand drops.