Tens of millions of gallons of water are flowing through a major pipeline in North San Diego County after successful repairs on a distressed section of Pipeline 4. The urgent repair project is a testament to the San Diego County Water Authority’s proactive Asset Management Program, which helps maintain water supply reliability while saving ratepayers money.
Tens of millions of gallons of water are flowing through a major pipeline in North San Diego County after successful repairs on a distressed section of Pipeline 4. The urgent repair project is a testament to the San Diego County Water Authority’s proactive Asset Management Program, which helps maintain water supply reliability while saving ratepayers money. The pipeline near Bonsall, returned to service in March, after a 10-day shutdown.
Water Authority staff detected potential pipeline weaknesses just north of West Lilac Road in 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.
As a result of the frequency or rate of change of wire breaks, Water Authority staff began preparing in late January for a 10-day shutdown to replace two distressed sections of pipe.
The pipe was delivered on February 28.
The pipeline was shutdown March 1.
By that evening, the pipe was nearly excavated.
The next morning, March 2, the Water Authority asset management team performed
an evaluation of the wire breaks.
After the inspection, the installation of the new steel pipe started, including rebar
work for the concrete encasement. On March 5, the contractor poured 12 truckloads of concrete for the encasement.
Once the pipeline replacement work was completed, crews
took a final walk through of the pipe in preparation of refill.
Maintenance crews reset a blowoff valve assembly that was removed for access to the pipeline.
By the last day of the 10-day shutdown, the contractor had pulled the shoring and was completing backfill, allowing the pipeline to be put back into operation according to schedule.
Pipeline 4 repair work included collaboration with five North County member agencies served by the pipeline, and operations staff from throughout San Diego County, which helped plan and execute the timely completion of the repair.
The asset management team uses the latest inspection technologies to detect age-related defects that might be occurring on pipelines and other water conveyance facilities. By identifying defects early, they can often be corrected using localized, low-cost repair methods prior to them becoming larger, more costly issues.
The Water Authority operates and maintains a regional water delivery system capable of delivering more than 900 million gallons of water per day. The system consists of 310 miles of large-diameter pipeline, 1,600 aqueduct-related structures, and approximately 100 metering/flow control facilities.
March 9, 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.
(Editor’s Note: B-roll video and photos of Pipeline 4 work: https://bit.ly/3hUsIkc)
The San Diego County Water Authority is proactively fixing a 90-inch diameter pipeline in Bonsall. The work is part of the agency’s long-term commitment to maintaining regional investments in water supply reliability and affordability.
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 Water Authority’s high-tech asset management program.
The San Diego County Water Authority is proactively fixing a 90-inch diameter pipeline in Bonsall as part of the agency’s long-term commitment to maintaining regional investments in water supply reliability and affordability.
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 Water Authority’s high-tech asset management program.
Next week, San Diego County Water Authority staff and contractors will begin crucial repairs on Pipeline 5 in rural North County between Fallbrook and Escondido.
The work is part of the Water Authority’s proactive asset management program, which monitors and maintains the condition of regional water infrastructure that includes 310 miles of large-diameter pipelines. The Water Authority’s approach, coordinated closely with its member agencies, has served the region well by avoiding large-scale, unexpected water outages for more than a decade.
After a leak in nearby Pipeline 4 was discovered in Moosa Canyon last summer, Water Authority staff assessed the conditions of Pipelines 3 and 5, which run parallel to Pipeline 4 as part of the Second Aqueduct. The assessment showed that a section of Pipeline 5 in Moosa Canyon was also under significant stress.
“Due to the very high operating pressure and the major consequences of potential failure of Pipeline 5, our staff immediately began planning a shutdown and repairs to mitigate risks,” said Jim Fisher, director of operations and maintenance at the Water Authority. “Our asset management program is designed to identify potential problems and respond quickly.”
After a leak in nearby Pipeline 4 was discovered near Moosa Creek last summer, Water Authority staff assessed the conditions of Pipelines 3 and 5, which run parallel to Pipeline 4 as part of the Second Aqueduct. Photo: San Diego County Water Authority
Constructed in 1982, Pipeline 5 is a vital component of the Water Authority’s water system, delivering untreated supplies from Lake Skinner in southwest Riverside County to the Lower Otay Water Treatment Plant in southern San Diego County. The operating pressure exceeds 400 pounds per square inch in Moosa Canyon.
Repairs will require that a section of Pipeline 5 in North County be shut down from March 30 until mid-May. Crews will start by installing bulkheads that isolate the Moosa Canyon section. Then, they will line the inside of the pipe with a carbon fiber liner, as was done to rehabilitate Pipeline 4. The carbon fiber liner will reinforce distressed areas and extend the life of the 96-inch, pre-stressed concrete cylinder pipeline.
The asset management program is a key element of the Water Authority’s commitment to providing a safe and reliable water supply to San Diego County. By making preventative repairs, the Water Authority ensures that water service will continue throughout the county.
Over the next 18 months, Water Authority staff will conduct a planning study to evaluate improvements required for all three pipelines in Moosa Canyon to ensure the long-term reliability of the Second Aqueduct. The results of the study will include recommendations about future projects as part of the Water Authority’s capital improvement program.
The completion of the emergency repair to the San Diego County Water Authority’s Pipeline 4 in Moosa Canyon led the SDCWA board to approve notices of completion which will release funds to the contractors, and the CWA board also ratified the final change order for the repair work.
The Nov. 21 CWA board action accepts the emergency repair work by J.F. Shea Construction Inc. and the carbon fiber repair work by Fibrwrap Construction Services Inc. as complete while also ratifying a $200,000 change order in the emergency contract with J.F. Shea.
Pipeline 4 – one of the San Diego region’s major water pipelines – is back in regular service after a leak was repaired, a testament to the San Diego County Water Authority’s proactive asset management program.
The pipeline resumed normal operations November 10 after nearly two months of modified operation. The leaky section was near Camino Del Rey in Bonsall, in an area with no adjacent homes or businesses.
“The shutdown and repair work went smoothly, and we could not have done it without the support and coordination from Water Authority staff, our contractors and member agencies, particularly, Fallbrook PUD, Rainbow MWD, Valley Center MWD, and Vallecitos Water District,” said Neena Kuzmich, Water Authority engineering manager.
Water Authority crews detected a leak in the 90-inch diameter Pipeline 4 in the Moosa Canyon area in August.
Crews installed bulkheads in the pipeline to isolate the leak area for repairs. The bulkheads allowed the pipeline to continue treated water deliveries throughout the county in a modified fashion and restored full service to retail water agencies.
The Water Authority installed a carbon fiber liner to give the pipeline several more years of service, while a longer-term solution is developed and implemented.
Once the repairs were completed, a second shutdown was needed to remove the bulkheads and return the pipeline to full, normal operations.
Pipeline 4 is one of five major pipelines operated by the Water Authority.
Crews installed a carbon fiber liner to repair a leak in Pipeline 4. The liner will give the pipeline several more years of service while a longer-term solution is developed. Photo: Water Authority
By relining the pipes and conducting timely repairs with the latest technology, the Water Authority has avoided major pipeline failures for more than decade.
Extending the life and reliability of major pipelines is one facet of the agency’s proactive asset management program. Real-time monitoring and other pipeline assessment tools help the Water Authority avoid pipeline failures by identifying potential problems in advance.
As part of its proactive approach, the Water Authority continually assesses and rehabilitates pipelines serving the San Diego region. The agency operates 310 miles of large-diameter pipelines, along with 1,600 aqueduct-related structures, and approximately 100 metering/flow-control facilities.
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 have experienced premature failures and shown areas of degradation.
In the past few years, the Water Authority has continued to extend the service life of pipelines with relining projects, including Pipeline 3 between Lake Murray and Sweetwater Reservoir, and Pipeline 5, in the Fallbrook area.
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.
Several engineers will spend the next few weeks 20 feet underground fixing a crack in a large water pipeline that spans almost the entire length of San Diego County.
The San Diego County Water Authority discovered a leak earlier this month in a portion of its 90-inch Pipeline 4, which has carried water since 1966 from the Skinner Water Treatment Plant near Temecula down to the Otay Reservoir near Chula Vista.
“We have very old, aging infrastructure so we’re always keeping tabs on things to make sure we can stay ahead of any failures or issues with our pipe,” said SDCWA Principal Engineer Brent Fountain.
