Amiblu GRP jacking pipes strengthen Auckland’s wastewater infrastructure

Country

New Zealand

City

Auckland

Timeline

2025

Application

Sewer

Total Length

600 m

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Amiblu Hobas GRP jacking pipes provided a robust, low-risk solution for Watercare’s Queen Street Wastewater Diversion, enabling trenchless installation at depths of up to 14 metres beneath one of Auckland’s busiest urban corridors.

The Queen Street Wastewater Diversion is a key part of Auckland’s midtown regeneration, increasing wastewater capacity for future residential and commercial growth while helping to reduce overflows into the Waitematā Harbour. The location beneath one of the city’s busiest urban corridors called for a reliable solution that could meet demanding structural requirements while minimising disruption at street level.

For the project, Amiblu supplied 600 metres of OD 1229 Hobas GRP jacking pipes, manufactured using centrifugal casting technology. With an exceptionally high stiffness of SN 200,000 and designed for jacking forces of up to 5,518 kN, the pipes provided the structural performance required for the challenging installation. Their corrosion resistance, smooth inner surface and high load-bearing capacity make Amiblu GRP jacking pipes particularly well suited to durable, hydraulically efficient wastewater systems and demanding trenchless applications.

Installed by McConnell Dowell and Fulton Hogan at depths of up to 14 metres, the pipeline was constructed using a hybrid combination of direct pipe and traditional pipe jacking – the first application of this approach in Aotearoa, New Zealand. The trenchless methodology enabled the new sewer to be installed beneath central Auckland while keeping disruption at the surface to a minimum.

Completed in 2025, the new pipeline strengthens Auckland’s wastewater network and provides additional capacity for future growth. The successful installation demonstrates how innovative trenchless construction combined with high-performance Amiblu GRP jacking pipes can provide a reliable solution for complex urban infrastructure.