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Historic First Aqueduct-asset management-Pipeline 1-maintenance

Work Begins on Water Authority’s Historic First Aqueduct

The San Diego County Water Authority’s First Aqueduct will be shut down periodically over the next four months for maintenance projects to ensure a safe and reliable water supply for the region. A series of three shutdowns on the First Aqueduct is scheduled from December through March, when portions of the aqueduct will be relined, along with other maintenance.

The Water Authority and its member agencies are coordinating to minimize impacts to residents and businesses, while servicing pipelines that are more than 65 years old.

Customers of these affected retail agencies during the Dec. 5-14 shutdown should check with their local water utility if they have questions about localized impacts: Fallbrook Public Utility District, Rainbow Municipal Water District, Rincon del Diablo Municipal Water District, Vallecitos Water District, Valley Center Municipal Water District, Vista Irrigation District, and the Yuima Municipal Water District.

Proactive Asset Management Program

“Proactively managing our water delivery system in coordination with our member agencies ensures we continue to provide a safe and reliable supply that serves the region’s 3.3 million residents and our $240 billion economy,” said Eva Plajzer, the Water Authority’s director of operations and maintenance. “It requires an extraordinary amount of work each fall and winter during the shutdown season to take care of this critical infrastructure.”

Maintenance work on pipelines is scheduled during low-demand periods to minimize impacts on water service. The other scheduled shutdowns on the First Aqueduct are January 23 to February 1 and February 27 to March 8. The February 27 to March 8 shutdown will also impact the Helix Water District and the cities of San Diego, Poway and Ramona.

Historic First Aqueduct

The historic First Aqueduct was constructed in the 1940s with Pipeline 1 and in the 1950s with Pipeline 2. On November 28, 1947, the first Colorado River water flowed south from Riverside County for 71 miles into the City of San Diego’s San Vicente Reservoir via the First Aqueduct.

First Aqueduct-Asset Management-Historic First Aqueduct-Shutdown

By order of President Franklin D. Roosevelt, the U.S. Navy built the San Diego Aqueduct to deliver Colorado River water to San Diego. Photo: San Diego County Water Authority archives

Asset Management Program

The Water Authority’s Asset Management Program is a key element of providing safe and reliable water supplies to the region. The agency continually assesses and inspects its 310 miles of large-diameter pipelines, which provide treated and untreated water to 24 member agencies in San Diego County. The program is widely recognized for pioneering work – including a patented inspection device – that promotes water affordability by avoiding costly unplanned disruptions in service.

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. Identifying potential issues early avoids more costly fixes later.

(Editor’s Note:The Fallbrook Public Utility District, Rainbow Municipal Water District, Rincon del Diablo Municipal Water District, Vallecitos Water District, Valley Center Municipal Water District, Vista Irrigation District, and the Yuima Municipal Water District are seven of the San Diego County Water Authority’s 24 member agencies that deliver water across the metropolitan San Diego region.)

Major Rehabilitation of First Aqueduct Complete

The San Diego County Water Authority recently completed a major rehabilitation project on the historic First Aqueduct in North San Diego County. The project renovated and replaced dozens of structures on two large-diameter pipelines, including the historic Pipeline 1. Pipeline 1 delivered the first imported water to the San Diego region in 1947 and remains a vital part of the regional water delivery system. The construction contract for the project was worth approximately $30 million.

Water Authority Rehabilitates Historic ‘First Aqueduct’ Dating to 1947 in North County

The San Diego County Water Authority has completed a major rehabilitation project on the historic First Aqueduct in North San Diego County, it was announced Thursday.

The project renovated and replaced dozens of structures on two large- diameter pipelines which delivered the first imported water to the San Diego region in 1947 and remains a part of the regional water delivery system. The construction contract for the project was worth approximately $30 million.

Crews work on First Aqueduct Rehabilitation.

Major Rehabilitation of First Aqueduct Complete

The San Diego County Water Authority recently completed a major rehabilitation project on the historic First Aqueduct in North San Diego County. The project renovated and replaced dozens of structures on two large-diameter pipelines, including the historic Pipeline 1. Pipeline 1 delivered the first imported water to the San Diego region in 1947 and remains a vital part of the regional water delivery system. The construction contract for the project was worth approximately $30 million.

Coordination with member agencies key to success

Over the past two years, four coordinated shutdowns in collaboration with member agencies and communities in North San Diego County ensured minimum impact to nearby neighborhoods and water users.

“The First Aqueduct delivered imported water to our region for the first time more than 70 years ago, and it remains critical to water supply reliability for our region to this day,” said Gary Croucher, chair of the Water Authority Board of Directors. “Through coordination throughout the Water Authority and collaboration with our member agencies, we completed this extraordinarily complex project to ensure these pipelines operate for generations to come.”

The project was completed on January 12 and will be presented to the Water Authority’s Board of Directors at their March meeting.

Proactive asset management program maintains reliable water supplies

The timely rehabilitation of the First Aqueduct is part of the Water Authority’s proactive asset management program. A key element of providing safe and reliable water supplies is continually assessing the agency’s 310 miles of large-diameter pipeline and making the upgrades necessary to continue serving the region. That work is funded through water bills paid by residents and businesses across the county to sustain the region’s $245 billion economy and quality of life.

The First Aqueduct project began in early 2019 and was one of the most complicated pipeline retrofits in the Water Authority’s history. The upgrades included replacing 14,500 linear feet of lining on the steel pipe sections of Pipeline 1, removing 16 associated structures and retrofitting 46 structures. All this work was accomplished while ensuring regional water service remained safe and reliable. In addition, redundant connections to six flow control facilities were added between the two pipelines to improve the aqueduct’s operational flexibility.

Collaboration between departments increased efficiency

The Water Authority’s Engineering Department provided construction management and inspection for the retrofit. Before the pipeline was returned to service, secondary tie-in connections to flow control facilities were added and crews removed bulkheads that were used to isolate pipeline sections during the rehabilitation work. Once the work was completed, staff inspected all work areas in the pipeline to ensure they were clear of construction debris.

After the bulkheads were removed, the Operations and Maintenance team disinfected the highly impacted work areas and then refilled the aqueduct to prepare for a second disinfection of both pipelines with chlorine. Water samples at locations throughout the aqueduct were collected and analyzed to ensure the system was safe to return to service. Once all the samples passed analysis, all flow control facilities were placed back in service and the aqueduct was returned to normal operations.

By order of President Franklin Delano Roosevelt, the U.S. Navy built the San Diego Aqueduct to deliver Colorado River water to San Diego. It is now known as Pipeline 1. Photo: SDCWA

1947: Construction of the First San Diego Aqueduct

San Diego became a hub of Naval Activity after the Japanese bombed Pearl Harbor and the United States entered World War II in 1941. The city’s population doubled in two years, and water use also doubled. It was clear the city and the Navy would soon need water from the Colorado River. An aqueduct for bringing that water to San Diego became a top priority.

The Navy was willing to help build the aqueduct, and let the City of San Diego pay it back. On November 28, 1947, the first Colorado River water finally flowed south from the Colorado River aqueduct’s western end in Riverside County for 71 miles into the City of San Diego’s San Vicente Reservoir near Lakeside via the San Vicente Aqueduct, now known as Pipeline 1 of the First San Diego Aqueduct. It ran over some of the county’s most rugged terrain and could deliver 65,000 acre-feet per year. At a time when all of San Diego County had less that three weeks’ water supply remaining, the completion of the project came just in time.