Metropolitan Water District of Southern California Second Lower Feeder PCCP Rehabilitation Reach 2
The Metropolitan Water District of Southern California owns and maintains the regional water system that provides Southern California with imported water supplies. The District manages the delivery of drinking and groundwater to 19 million people within their service area.
The District continually monitors the condition of the Colorado River Aqueduct, pumping plants, treatment plants, and 830 miles of pipelines to assess the need for rehabilitation projects. The Second Lower Feeder is one of the major pipelines in the system. Constructed in 1967 of Prestressed Concrete Cylinder Pipe (PCCP), it delivers treated water from the Robert B. Diemer Water Treatment Plant in Yorba Linda to the Palos Verdes Reservoir in Rolling Hills Estates. The District is rehabilitating 28 miles of this pipeline due to general failure and water loss. They selected the ‘reliner’ method to rehabilitate this portion of the pipeline.
Simply stated, the relining process involves inserting collapsed steel pipe into a failing system, expanding the steel pipe and securing it within the existing pipeline, which will provide secure service for decades to come. We compress and secure the steel pipe lengths with steel bands that are ‘released’ when in place, causing the pipe to expand and fit inside the host pipe. Field crews install joints to connect the pipe pieces and use grout to secure the pipe within the system, while only losing one to three inches of internal pipe diameter. A field team uses entry and exit portals at the two ends of the pipeline to keep excavation to a minimum. For the Second Feeder Reach 2, the diameter of the pipe went from 78” OD PCCP pipe to 75” OD on the new ‘relined’ system.
This minimally invasive approach reduces construction impact and the affect on the community, traffic, and environment.
Northwest Pipe is supplying 5,474 tons of pipe on the Reach 2 project that will rehabilitate approximately 4.5 miles of this major regional water pipeline. In a previous contract for Reach 4, we manufactured 944 tons of steel reliner pipe.