Seddon Road wastewater diversion
We’re upgrading the Seddon Road wastewater Pump Station and installing a new wastewater pipeline to connect the station to the Western Interceptor near Avalon Drive.
What we're doing
We’re upgrading the Seddon Road wastewater Pump Station and installing a new wastewater pipeline to connect the station to the Western Interceptor near Avalon Drive.
The Seddon Road Pump Station helps move wastewater from homes and businesses through to Hamilton’s wastewater treatment plant in Pukete.
Much of the pipeline will be installed underground using drilling methods, which reduces the need for open trenches and helps minimise disruption for residents and road users. Some excavation will still be needed to connect sections of pipe and install manholes.
Wastewater from your home or business is expected to continue as normal during the works.
Why we’re doing it
Hamilton’s wastewater network needs more capacity to support growth, enabling more future housing and development.
The Seddon Road Pump Station currently connects to the Central Interceptor. By upgrading the pump station and diverting flows to the Western Interceptor near Avalon Drive, we can create more capacity in the city centre and improve the reliability of our wider wastewater network.
This project is being delivered by IAWAI and part of a wider $3.3billion programme of water infrastructure upgrades we will be delivering across Hamilton.
This project will support Hamilton Central City Transformation plan to enable 4,000 new homes in the inner city by 2035. The project is funded through the Government’s Infrastructure Acceleration Fund (IAF).
How we’re doing it
The new pipeline will travel west along Seddon Road and Rimu Street, under Forest Lake Road, then south on Tui Avenue, before crossing under the North Island Main Trunk Railway and State Highway 1C (Mangaharakeke Drive) to connect to the Western Interceptor near Avalon Drive.
The route has been selected after considering technical requirements, existing underground services, property constraints, environmental effects and construction feasibility. It provides the best balance of network performance, constructability and long-term value for the city.
Most work will take place in the road corridor. Traffic management will be in place as needed, and access to properties will be maintained wherever possible. If temporary access changes are required, we’ll contact affected residents and property owners in advance.
The overall project is expected to take around 10 months between July 2026 and mid-2027 and will be completed in stages along the route.
Keeping you informed
We’ll keep nearby residents, property owners, businesses and other affected stakeholders informed before and during construction. This will include updates about construction timing, traffic management, access changes and any work happening near individual properties.
Project updates will also be available on this webpage throughout construction. If you have any questions, email us at info@iawai.co.nz
Who’s responsible for this project?
IAWAI is responsible for planning and delivering the Seddon Road wastewater diversion and improvements project.
HEB Construction is the contractor appointed to carry out the physical works.
Where we're at
Phase 1 – Complete
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Project planning and design
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Investigations and route selection
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Detailed design
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Consenting and procurements
Phase 2 – Underway
July 2026 to February 2027
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Pipeline installation underway
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New wastewater pipeline installation
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Pipe crossing beneath KiwiRail Corridor and SH1C
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Connection of downstream end of new pipeline to the Western Interceptor
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Traffic management and access coordination
Phase 3 – Planned
January to Mid-2027
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Pump station upgrade
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Improvements to existing Seddon Road wastewater Pump Station
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Connection of new pipeline to Seddon Road Pump Station
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System testing and commissioning
Phase 4 – Planned
Mid-2027
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Project completion
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Final commissioning and operational testing
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Site reinstatement
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Project close-out
Engagement timeline
May-June 2026Project information prepared, stakeholder planning and project notifications.
July-August 2026Construction begins and communications with affected residents, businesses and road users.
September-November 2026Ongoing engagement with nearby properties as construction progresses through the project corridor.
December 2026-January 2027Updates on construction progress, upcoming works and changes to traffic management where required.
January-April 2027Pump station upgrade works and network commissioning. Ongoing project updates provided.
Mid-2027Construction completion and project close-out.
FAQs
Will I still be able to access my property?
Access to properties will be maintained wherever possible. If temporary access changes are needed, we’ll contact affected residents or property owners in advance.
Will my wastewater service be affected?
Wastewater services are expected to continue as normal during the works. We’ll connect the new pipeline to the pump station once it is ready.
How long will construction take?
Construction is expected to take around 10 months, from July 2026 to mid-2027. Work will be completed in stages along the route.
Who can I contact for more information?
Project updates will be available on this webpage throughout construction. If you have any questions, email info@iawai.co.nz