The local chapter of the American Public Works Association honored the Pipeline 5 relining project for the successful collaboration between the Water Authority, contractor, local agencies and nearby communities. Photo: San Diego County Water Authority

Major Relining Project Honored by the American Public Works Association

The San Diego and Imperial Counties Chapter of the American Public Works Association recently recognized a San Diego County Water Authority pipeline relining project for its excellence as a public works project. The award commends the successful partnership between Water Authority staff, the contractor and local agencies working together to complete this critical repair to maintain the reliability of the regional water supply.

Relining project covers 12,300 feet

Pipeline 5 was relined from the point of delivery with the Metropolitan Water District of Southern California to Sage Road in the Fallbrook and Rainbow communities in north San Diego County. The $24.7 million project was completed in July 2019 and relined approximately 12,300 feet of Pipeline 5, a 96-inch large-diameter regional pipeline.

30-year pipeline relining program rehabilitates aging pipes

Relining is a cost-effective method to repair pipelines and extend their service life with less impacts to the community and environment than if a traditional pipe replacement is performed. The relining process avoids digging up miles of pipeline, which would take significantly more time and resources, as well as impact associated streets and driveways for a long period of time.

“The Water Authority’s asset management program used an acoustic fiber monitoring system to help perform evaluations of the pipeline and prioritize this portion for rehabilitation,” said Jerry Reed, director of engineering at the Water Authority. “Our staff collaborated with stakeholders in Fallbrook, San Marcos and Rainbow, including staff at our member agencies and nearby residents to ensure project success.”

The project work areas were surrounded by residential homes and farms, heavily traveled public streets and a local retirement community.

Close coordination with multiple agencies ensured there were no impacts to water deliveries. Open communications with local residents regarding project schedule ensured no incidents occurred with local traffic.

Proactive asset management program rehabilitates crucial water infrastructure

The relining project was part of the Water Authority’s proactive and innovative asset management program to rehabilitate and reline pre-stressed concrete cylinder pipe within the Water Authority’s conveyance system to ensure continued supply reliability.

The local APWA chapter chose the project based on criteria that included superb planning, efficient design and construction management techniques to complete the project on schedule, within a cost-effective budget and adherence to regulatory requirements. It was also judged on the degree it enhanced a public service or facility, the quality of community relations or actions to minimize public impacts, safety precautions taken to protect lives and property, environmental impact mitigation measures and other accomplishments under adverse conditions.

The Water Authority is in the final stages of the Lake Murray to Sweetwater Reservoir Pipeline 3 Relining Project, including the restoration of roadways to pre-construction condition. La Mesa Relining Project

La Mesa Relining Project on Pace for Completion in June

Major construction activities have concluded at a pipeline relining project in La Mesa and Spring Valley, and the entire project is on track for completion by the end of June.

The Lake Murray to Sweetwater Reservoir Pipeline 3 Relining Project rehabilitated 4.3 miles of 66- and 69-inch diameter pipes, extending the pipeline’s service life by several decades and helping ensure continued water system reliability.

The timely success of the project underscores the value of collaboration by the Water Authority’s project team; public agency stakeholders such as the city of La Mesa and Helix Water District; and the contractor, L.H. Woods & Sons, Inc.

Construction began in September 2017. The bulk of the work was performed underground, through portals, which allow easy access to the pipe. This process is about half the cost of a conventional pipeline replacement project and is less disruptive to the environment and surrounding communities.

Project part of larger Water Authority effort

The 4.3-mile project is part of a larger effort by the Water Authority to rehabilitate 82 miles of its pre-stressed concrete cylinder pipe installed between the early 1960s and 80s throughout the county. This type of pipe has been found to be less reliable than previously thought. In response, the Water Authority launched the Pipeline Relining Program to reinforce these pipes with steel liners, increasing their service life by 75 years or more.

With the last of the new steel liners installed, welded, grouted and lined with cement mortar, the remaining work includes site restoration – such as re-paving and re-striping roadways – and demobilizing.

With the completion of the Lake Murray to Sweetwater project, the Water Authority has rehabilitated more than half of its pre-stressed concrete cylinder pipe.