About the
project
Surbiton Trunk Main Renewal
Tooting High Street (A24) To Balham High Road, South London
Clean Water Engineering
RWP provided detailed design services for the renewal of a strategic trunk main through South London, from Tooting High Street to Balham High Road, replacing ageing infrastructure along one of the capital’s busiest road corridors.
The disciplines involved in this project were:
- Clean Water Engineering
- Highways Engineering
- Temporary Works
2022 - 2024
The Surbiton Trunk Main renewal involved the replacement of a critical clean water asset running beneath the A24 corridor through South London. The existing main had reached the end of its serviceable life, with increasing burst frequency presenting supply risk to a large area.
RWP’s design addressed the complex challenges of working beneath a major arterial road, including deep excavation with sheet piling, traffic management on a Transport for London Red Route, and coordination with extensive buried services. The design specified shaft construction at key locations to facilitate the pipe installation.
The project required close coordination with TfL, Thames Water operations and the construction contractor to manage the impact on this heavily trafficked corridor.
Key Challenges
- Working beneath a TfL Red Route with heavy traffic volumes.
- Deep excavation requiring sheet piling in urban setting.
- Extensive buried services along the A24 corridor.
- Maintaining supply to a large customer base during works.
- Coordination with TfL, Thames Water and utility providers.
Project Phases
- Buried services investigation and route verification.
- Detailed design of pipeline and shaft construction.
- Temporary works and traffic management design.
- Construction support and design queries.
- Commissioning and connection.
Achievements
- Design delivered enabling construction on this constrained corridor.
- Effective shaft construction methodology developed.
- Traffic impact minimised through careful staging.
- No unplanned supply interruptions.
- Strong coordination with TfL maintained throughout.
Conclusion
- Red Route works require early TfL engagement.
- Shaft-based construction reduces surface disruption on busy roads.
- Detailed buried services data is essential for urban trunk main design.
The Surbiton Trunk Main Renewal demonstrates RWP’s capability in delivering complex clean water infrastructure beneath major urban road corridors, managing the technical and logistical challenges of working in one of London’s busiest environments.
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