Ensuring water flows freely from our taps as Auckland grows

As demand for water grows in Auckland, Hunua 4 Watermain ensures that there’s sufficient network capacity to continue an uninterrupted, high quality water supply.

When filling up the kettle for a coffee or hopping into our morning shower, we often take it for granted that water will always be available. To make sure that water is always on tap as Auckland grows, Watercare, with support from CH2M Beca and GHD, is delivering the Hunua 4 Watermain.

One of the largest bulk water supply pipelines in Auckland, it’s a huge challenge. There’s 28km of potable water supply pipeline that traverses Auckland, from the south to the centre. This central route means it needs to go underneath major roads, city and suburban streets, railways, stormwater and sewerage networks, an old landfill site and more.

Avoiding as much disruption as possible to residents and travellers is key to this project. That’s why we focused on evaluating alternative routes over approximately 33% of the watermain’s length. It includes amending the original route to avoid Manukau city centre's heavy traffic, and the congested areas of Onehunga.

Realising such a major project involves careful planning. Working alongside Watercare, we coordinated all scientific, engineering and cultural investigations, including preparing the applications. We also undertook detailed design, cost estimates and construction monitoring.