Work progresses on $66 million upgrade to San Diego’s first aqueduct
(UI) — The San Diego County Water Authority has reached the halfway point on a $66 million project to extend the life of the historic First Aqueduct and maintain reliable water delivery across the region.
The Southern First Aqueduct Facilities Improvement Project, set to continue through summer 2026, involves renovations to 99 structures along two large-diameter pipelines running from North to South County.
“The First Aqueduct has served our region for over 70 years, and this investment is about making sure it continues to do so reliably,” said Nick Serrano, chair of the San Diego County Water Authority Board of Directors. “This project is a great example of our water bills at work – ensuring that the infrastructure delivering safe and clean water to our homes and businesses remains strong for generations to come.”
The First Aqueduct, built in the late 1940s and 1950s, supplies 11 water agencies countywide. The three-and-a-half-year project covers a 21-mile stretch, beginning north of Escondido and east of Interstate 15, continuing south through Slaughterhouse Canyon in unincorporated San Diego County, and ending at San Vicente Reservoir in Lakeside. The work spans Escondido, Poway, Rancho Bernardo, and parts of unincorporated San Diego County.
Phase One, which began in spring 2024, focused on Pipeline 2 structures and is scheduled to conclude at the end of February. Once completed, work will shift to Pipeline 1 while keeping the other pipeline operational to prevent water service interruptions.
“As Phase One of the project moves toward completion, the Water Authority is grateful to the many neighbors and property owners impacted by the construction for their patience and support as this vital work continues,” Serrano said. “By making these improvements before they become urgent, we avoid more costly repairs and reduce the overall cost of system maintenance while keeping our water supply safe and the taps flowing.”
To transition to Phase Two, crews will work around the clock for 10 days from Feb. 23 to March 4, with night work planned at seven locations. Most sites are in undeveloped areas with minimal impact on residents or businesses.
The Water Authority is working closely with member agencies to minimize disruptions and ensure uninterrupted water service.
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