Clearwater Tunnel Inspection Finds Initial Area 'Stable and Intact'

Crews continue drilling to assess conditions above 360-foot breach in San Pedro.

Published on Feb. 6, 2026

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The investigation into the Clearwater wastewater tunnel breach in Los Angeles has found that the initial 3-mile section of the tunnel is in stable and intact condition, allowing inspectors to move forward with further assessments. Drilling activity on Western Avenue continues as crews work to better understand the underground conditions and determine the best method for filling and reinforcing the area around the breach, which occurred about 360 feet below street level.

Why it matters

The $630 million Clearwater Tunneling Project is a critical infrastructure undertaking to install new regional wastewater pipes, and the breach in July 2025 temporarily halted progress. Ensuring the safety and stability of the existing tunnel is a key step before work can resume on the final leg of the project, which will connect to the end point at Royal Palms Beach.

The details

Inspection teams were allowed inside the Clearwater tunnel for the first time on December 8, 2025 and found the initial 3-mile section to be stable and intact. This has allowed the investigation to move forward, with Cal/OSHA authorizing a second phase of re-entry to inspect the tunnel up to 150 feet from the breach area. Crews have been using remote technology like ROVs and drones to assess conditions, and are now drilling multiple bore holes to better understand the underground situation and determine how to fill and reinforce the area around the breach.

  • On July 9, 2025, the underground breach temporarily trapped several workers, halting the Clearwater Tunneling Project.
  • On December 8, 2025, inspection teams were allowed inside the Clearwater tunnel for the first time.
  • On February 5, 2026, a new report stated the initial 3-mile section of the tunnel is 'stable and intact'.
  • In August 2025, construction at Royal Palms Beach was suspended following the discovery of Native American artifacts.
  • On January 21, 2026, the State Historic Preservation Office authorized Royal Palms Beach construction activities to resume.

The players

Los Angeles County Sanitation Districts

The agency overseeing the Clearwater Tunneling Project and conducting the investigation into the tunnel breach.

Cal/OSHA

The state occupational safety agency that has authorized further re-entry and inspection of the Clearwater tunnel.

State Historic Preservation Office

The agency that authorized the resumption of construction activities at the Royal Palms Beach site after a five-month archaeological investigation.

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What’s next

The entire length of the Clearwater tunnel from Carson to San Pedro — about seven miles — will be carefully inspected before work on the final leg of tunneling can resume. Limited construction work at the Royal Palms Beach site is expected to resume in the next few months to prepare for the eventual connection to the new tunnel.

The takeaway

The Clearwater Tunneling Project has faced significant challenges with the unexpected tunnel breach, but the latest inspection findings indicate progress is being made to assess and address the underground issues before work can continue on this critical infrastructure upgrade for the Los Angeles region.