Pipeline 4 repairs
A worker checks Pipeline 4 during repairs in 2019. Courtesy San Diego County Water Authority

The San Diego County Water Authority announced Monday that it will begin precautionary repairs to a key pipeline in Bonsall.

The Water Authority said its staff detected potential weaknesses in a 48-foot section of Pipeline 4 just north of West Lilac Road in late January using acoustic fiber-optic monitoring.

Plans are to shut down and drain that stretch of 90-inch diameter pipe starting Tuesday. Work to replace the segment will continue until the line is back in service approximately 10 days later.

“This repair highlights the value of strategic investments in money-saving asset management tools and training,” said Martin Coghill, a senior manager for operations and maintenance at the Water Authority. “By proactively identifying this problem spot, we prevented what could have been a major unplanned shutdown.”

The Water Authority has been coordinating closely with retail water agencies in North County that rely on deliveries from Pipeline 4, including Rainbow Municipal Water District, Fallbrook Public Utility District, the city of Oceanside, Valley Center Municipal Water District, and Vallecitos Water District.

Pipeline 4 carries supplies of Colorado River water from Metropolitan Water District facilities in Temecula to San Diego County.

When the pipeline is shut for repairs, the Water Authority’s system can deliver treated water from other sources, such the Carlsbad Desalination Plant and various local reservoirs.

Chris Jennewein

Chris Jennewein is Editor & Publisher of Times of San Diego.