Wairau Valley Branch Sewer Transmission Renewals
Renewing critical wastewater infrastructure to reduce overflows and improve network reliability.
Duration
May 2026 to October 2026 (subject to weather and site conditions)
Location
Wairau Valley, Totara Vale and Unsworth Heights, Auckland
Status
Construction
Project overview
Watercare is rehabilitating the Wairau Valley Branch wastewater network to improve the condition and reliability of existing wastewater infrastructure, reduce the risk of overflows, and help protect local waterways and the environment.
Most of this work is being completed using trenchless technology, which allows pipes to be renewed underground with minimal excavation and reduced disruption to surrounding communities.
The project includes pipeline rehabilitation, manhole improvements and associated renewal works across public reserves, roads, berms and selected private properties.
Where access to private property is required, Watercare and its contractor will work directly with affected owners and occupiers.
Benefits
This project will help:
• Reduce the likelihood of wastewater overflows
• Improve environmental outcomes and water quality
• Extend the life of critical wastewater infrastructure
• Improve the reliability and resilience of the wastewater network
What we are doing
The project team is rehabilitating sections of the Wairau Valley Branch wastewater network using trenchless relining technology and associated manhole improvements.
- Current and upcoming works include:
- Pipeline relining between existing wastewater manholes
- Investigation and cleaning of wastewater assets
- Manhole rehabilitation works
- Works within Unsworth Park and surrounding areas
- Property-specific works where access is required to maintain or renew wastewater infrastructure
Most works are undertaken from existing manholes, reducing the need for extensive excavation.
What happens next
Construction will continue through the remaining sections of the wastewater network over the coming months.
Upcoming activities include:
- Continued pipeline relining works
- Manhole rehabilitation works
- Works within Unsworth Park
- Selected works near Ayton Drive and Ellice Road
- Final reinstatement and rehabilitation activities following completion of major construction works
Where private property access is required, the project team will contact affected owners and occupiers directly before works commence.
Construction timeframes remain subject to weather, ground conditions and operational requirements.
See the map of the proposed work area below:

Click to view the full-sized map
How will these works affect you?
As work progresses, you may notice:
- Temporary traffic management in some locations
- Construction noise during working hours
- Crew vehicles accessing work sites
- Temporary fenced work areas within reserves and public spaces
- Occasional wastewater odour when manholes are opened
Most activities are short duration at each location before crews move to the next section of the network.
Water and wastewater services are generally expected to remain operational throughout the works.
Residents and property owners directly affected by upcoming works will receive notification before construction begins.