Work to pump a slurry into bore holes on Western Avenue are set to resume in the coming days as assessments of an underground Clearwater tunnel breach undergoes further work. Single-lane closures will be required on Monday, May 11, Wednesday, May 13, and Thursday May 14 during construction hours.
One southbound lane will be closed from 6 a.m. to 6 p.m., with vehicle traffic using the lane adjacent to the sidewalk side of the road, a spokesperson said, reminding drivers to use caution as they drive though the area.
The Clearwater project, which began in 2019 and involves laying down two larger, underground wastewater pipes from Carson to Royal Palms Beach in San Pedro, has been halted now for nearly a year after a July 2025 breach temporarily stranded workers some 320 feet below Western just north of Ninth Street.
The project was nearing completion to lay the larger wastewater pipes underground when the breach occurred.
Work to assess and repair the breach while also inspecting the entire length of the tunnel to insure its overall stability has been ongoing since the incident — and is proving to be painstaking, a spokesperson said.
“Attempts continue to drain the large amount of water that has built up behind the debris pile (at the breach),” said Michael Chee, spokesperson for the Los Angeles County Sanitation Districts in an email responding to questions. “But draining the water to an acceptable level has proven difficult. There’s no timeframe for how long this will take. We continue to emphasize that conditions are complicated and safety is a primary concern inside the tunnel.”
Work on the $630 million, multiyear Clearwater Tunneling Project remains paused as workers also now are doing first-hand, in-person walking assessments of the underground structure to make sure it is stable. They now are about 150 feet from reaching the point of the breech, Chee said.
The work next week will entail a contractor pumping slurry — a cement mixture — into the boreholes to try to fill the surrounding voids down to the tunnel, Chee wrote.
“This will help stabilize the tunnel structure around the breach so that work can continue safely from inside the tunnel,” he said. “If we have problems with our bore holes or the weather, then the slurry pumping will be rescheduled until any issues are resolved.”
Attempts also continue, he said, to drain a large amount of water that has built up behind the debris pile but “draining the water to an acceptable level has proven difficult.”
“There’s no timeframe for how long this will take,” he said. “We continue to emphasize that conditions are complicated and safety is a primary concern inside the tunnel.”
The work and approvals to proceed, he added, remain at the discretion of CalOSHA.
“Longer term,” he said, “assuming the slurry effort on Western Avenue is successful and the water draining effort is as well, a plan is in place to begin removing debris and repairing the breach area inside the tunnel. This phase of work is very complicated and will take months.”
Meanwhile, Chee said limited construction continues at Royal Palms Beach to the south to prepare that location to connect to the tunnel in the future. That work began in March.
“This is planned work that needs to happen regardless of the tunnel breach,” he said.