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Aqueduct Shutdown Expected to Begin Nov. 4

The repair to the San Diego County Water Authority’s Pipeline 4 in Moosa Canyon will require a shutdown of the SDCWA aqueduct which is expected to begin Nov. 4, and the CWA’s actions also included a unanimous CWA board vote Oct. 24 to approve a change order in the CWA’s contract with Fibrwrap Construction Services, Inc.

The change order increases the contract by $140,409 to create a total contract amount of $1,011,751 while also amending the contract to increase the number of carbon fiber layers.

Pipeline relining is an efficient technique that extends the lifespan of pipes while minimizing costs and impacts to nearby communities. Photo: Water Authority

Innovative Pipeline 5 Relining Completed

San Diego County Water Authority crews completed relining a segment of Pipeline 5 in Fallbrook and San Marcos in late July, reaching a milestone in a strategic, multi-decade pipeline relining program. The 2.3-mile segment of Pipeline 5 was relined with new steel liners that are planned to last for more than 75 years.

The proactive pipeline relining program is a crucial part of asset management efforts that improve the reliability of San Diego County’s water supplies.

30-year pipeline relining program

Since the relining program began in 1991, nearly 47 miles of pre-stressed concrete cylinder pipe have been rehabilitated. This constitutes more than half of the total PCCP in the Water Authority system. The remaining 35 miles are expected to be rehabilitated by 2027.

The Pipeline 5 project was conducted in eight segments to minimize impacts to the nearby communities of Fallbrook and San Marcos.

Proactive measures to protect infrastructure

Pipeline relining is an efficient technique used on long stretches of pipelines. It involves inserting new steel liners into the existing pipes. The new liners can extend the lifespan of the pipe by several decades.

“Relining our existing pipes is quicker and more cost-effective than excavating, removing and replacing an entire pipeline,” said Gary Olvera, senior construction manager at the Water Authority. “In partnership with our member agencies, the Water Authority has developed an efficient and proactive plan to ensure continued water supply reliability for the entire region.”

New steel liners can extend the lifespan of a pipe by several decades. Photo: Water Authority

New steel liners can extend the lifespan of a pipe by several decades. Photo: Water Authority

Innovative technique to minimize impacts

To access Pipeline 5, crews excavated dirt to create eight 25-foot by 60-foot access portals spaced roughly 525 to 2,500 feet apart. During construction, crews eliminated two of the originally planned portals, helping save more than $217,000. Most of the work was then performed underground, inside the pipe.

Once the new liner was installed, the joints were welded together. Then, each new steel liner was coated with a cement mortar lining. Finally, the portals were backfilled, the pipeline was disinfected, and the pipe was put back into service.

A welder works inside the pipe to connect the new joints. Photo: Water Authority

A welder works inside the pipe to connect the new joints. Photo: Water Authority

Maintaining regional water supply reliability

Large-diameter pipelines operated by the Water Authority and its 24 member agencies extend approximately 310 miles to convey water throughout San Diego County.

Approximately 82 miles of the pipelines are pre-stressed concrete cylinder pipes. These types of pipes were installed between the early 1960s and late 1980s and some are nearing the end of their service life.

By relining the pipes ahead of time or conducting timely repairs with the latest technology, the Water Authority and its member agencies avoid pipeline failures and improve the reliability of future water supplies.

Innovative Pipeline 5 Relining Completed

San Diego County Water Authority crews completed relining a segment of Pipeline 5 in Fallbrook and San Marcos in late July, reaching a milestone in a strategic, multi-decade pipeline relining program. The 2.3-mile segment of Pipeline 5 was relined with new steel liners that are planned to last for more than 75 years. The proactive pipeline relining program is a crucial part of asset management efforts that improve the reliability of San Diego County’s water supplies. Since the relining program began in 1991, nearly 47 miles of pre-stressed concrete cylinder pipe have been rehabilitated. This constitutes more than half of the total PCCP in the Water Authority system.

The $24 million Pipeline 5 Relining Project in Fallbrook is expected to conclude in summer 2019. Photo: San Diego County Water Authority

Pipeline 5 Upgrades Begin in Fallbrook

A $25.3 million Pipeline 5 relining project is under way in North County to improve the reliability of the San Diego region’s water delivery system. The project involves rehabilitating approximately 2.3 miles of one of the San Diego County Water Authority’s regional wholesale water pipelines in eight segments along a 9.5-mile stretch through the community of Fallbrook.

Construction work will be done in phases and completed in summer 2019. When finished, the Pipeline 5 Relining Project will help extend the service life of this vital piece of infrastructure for more than 75 years. Generally, relining construction rehabilitates segments of pipelines based on their age and the need for improvements.

Relining process advances in well-planned stages

Construction activities in Fallbrook began September 19 with the installation of protecting fencing, establishing an entrance to the construction area, and clearing the site of all vegetation and debris for safety. The relining itself will begin in November.

In broad terms, the relining process begins with dirt being excavated to create an access portal or work area. The construction crews will conduct most of the work underground, inside the pipe. They will access the pipe by excavating, establishing, and entering the pipeline through nine access sites, or portals. The portals will be 25-foot by 60-foot excavated pits, spaced approximately 525 to 2,500 feet apart. At each portal site, 40 feet of existing pipe is removed to permit access inside the pipe to install relining materials.

The work involves removing 20-foot sections of old concrete pipe at each portals. Then, new steel liners are inserted into the existing pipe using a specialized pipe cart. Liners are installed into the entire pipe section. Once installed, the joints of the liner pipe are welded together. Each new steel liner is coated with a cement mortar lining. Finally, portals are backfilled and — after pipeline disinfection — the pipe is ready to be put back into service.

Community kept informed about project’s progress

Much of the construction work associated with the project is in Water Authority rights-of-way. Some portals within the unincorporated San Diego County portion of the alignment will be in undeveloped areas.

As people living and working in the area begin to see the activity, project team members will be available to address questions or concerns. Contact information including 24-hour phone numbers, email contacts, and website links are posted on nine informational signs along the construction route. Construction workers on site will also have contact information to pass out on request.

For more information, residents can call the 24-hour project information line at (877) 682-9283, ext. 7009 or email . A representative from the project team will respond within one business day.

Pipeline upgrades ensure safe, reliable water supplies

The Water Authority’s large-diameter pipelines extend approximately 310 miles to convey water throughout western San Diego County. Approximately 82 miles of these pipelines were installed between the early 1960s and late 1980s with pre-stressed concrete cylinder pipes, or PCCP, made from a combination of steel and concrete. First used during World War II to help minimize the use of precious steel, this pipeline type is used extensively around the world.

Numerous failures of similar pipes nationwide prompted the Water Authority to take proactive measures to reinforce its PCCP type pipelines with steel liners in an strategic, multi-decade program starting in 1991.

In addition, in 2003 the Water Authority started using an innovative carbon fiber technology to conduct urgent pipeline repairs, helping ensure a safe and reliable water supply to the region.

When the Fallbrook project is finished, the Water Authority will have rehabilitated approximately 47 miles of PCCP — more than half of the total in the Water Authority system.