Successful Pipeline 4 Repair Saves San Diego County Ratepayers Money

March 09, 2022

Tens of millions of gallons of water will soon be flowing again through a major pipeline in North County following successful repairs on a distressed section of Pipeline 4 near Bonsall.

San Diego County Water Authority staff detected potential pipeline weaknesses just north of West Lilac Road in late January using real-time acoustic fiber-optic monitoring. This technology locates distressed sections of pipelines even while they are in use as part of the agency’s high-tech asset management program.

The repair is part of the Water Authority’s proactive approach and long-term commitment to maintaining regional water supply. Strategic investments in money-saving management tools and training paid off when staff spotted a potential problem that could have led to an unplanned shutdown of a 7.5-foot diameter water pipeline.

The pipeline was shut down March 1 so repairs could begin. While Pipeline 4 was out of service, five North County water agencies that rely on it continued water deliveries by other means to homes and businesses.

Even during the shutdown, the Water Authority’s resilient system can deliver treated water to member agency connections from multiple sources, including the Carlsbad Desalination Plant.

The Water Authority operates and maintains a water delivery system capable of delivering more than 900 million gallons of water per day through 310 miles of large-diameter pipeline, 1,600 aqueduct-related structures, and approximately 100 metering/flow control facilities. It also includes a state-of-the-art water treatment plant, hydroelectric facilities, pump stations, flow regulatory structures, and reservoirs that store water for emergencies and dry years.

As assets age, the Water Authority proactively replaces and repairs them to minimize impacts to member agencies and the public. Investments in the latest inspection technologies, including electromagnetic scanning, robotic inspections and 3D tunnel inspections help the Water Authority’s asset management team detect defects in pipelines and related facilities. By identifying corrosion or other types of deficiencies early, potential problems are corrected so they don’t become large and more costly issues.

(Editor’s Note: B-roll video and photos of Pipeline 4 work: https://bit.ly/3hUsIkc.)

Tens of millions of gallons of water will soon be flowing again through a major pipeline in North County following successful repairs on a distressed section of Pipeline 4 near Bonsall.
  • The San Diego County Water Authority sustains a $268 billion regional economy and the quality of life for 3.3 million residents through a multi-decade water supply diversification plan, major infrastructure investments and forward-thinking policies that promote fiscal and environmental responsibility. A public agency created in 1944, the Water Authority delivers wholesale water supplies to 23 retail water providers, including cities, special districts and a military base.

    Media Contact Information

    Jordan Beane

    Phone: (858) 221-3975

    Email: jbeane@sdcwa.org