A leak was detected in a water main in the Hotel Circle area in the City of San Diego, prompting the City to initiate an emergency replacement schedule. The water line was originally scheduled to be replaced as part of the City’s Capital Improvements Program (CIP) Pipeline Replacement Program to upgrade the system with modern materials to help ensure the safe and reliable delivery of drinking water.

Accelerated Schedule

When an emergency leak in the existing pipe was detected, the project was fast tracked and bid as a stand-along project rather than remain part of the larger CIP project with complex permitting. Teams involved in the project used enhanced communication, close construction coordination, risk management and mitigation, and a critical path schedule to achieve a permanent, modern solution.

Pipeline Alignment

Due to the alignment crossing Interstate 8 in Mission Valley, a tunnel was required near the location where a previous tunnel had caused a noticeable rise in the freeway. To prevent additional damage to the freeway, close coordination with Caltrans was required during design and construction, including surveyed monitoring for any settlement during the tunneling process. Caltrans was on site during tunneling operations to observe the process and monitor construction activities. The location of the launching and receiving pits were key and resulted in a very efficient operation.

Safety, Community, and Environmental Considerations

The project site was close to a nearby park, so the site’s safety perimeter was extended beyond normal requirements, preventing park patrons – especially children – from entering the site. To accommodate cyclists, an existing bike path was moved and re-paved. To prepare the site for safe use, ADA improvements were made and streets were re-paved. The City and contractor held public meetings and distributed digital and print notifications to nearby residents and businesses during the design and construction phases.

The project site was adjacent to the San Diego River – an environmentally and ecologically sensitive habitat. To minimize impacts to sensitive bird species, construction was scheduled outside the bird breeding season. In addition, Baker tanks were used to perform dewatering activities.

Project Results

By replacing the CI and AC water delivery lines, the City increased the resiliency and reliability of San Diego’s water infrastructure and proactively prevented the loss of water (a precious resource in Southern California) due to water main breaks. The project was awarded an Honor Award by the American Public Works Association (APWA), San Diego and Imperial Counties Chapter (2023).

Project Details

Location:
San Diego, CA
Owner:
City of San Diego