Auckland’s Central Interceptor is now fully operational, marking the completion of one of New Zealand’s most significant infrastructure projects

Delivered by the Ghella Abergeldie Joint Venture for Watercare, the Central Interceptor is the largest wastewater infrastructure project in New Zealand’s history. Over seven years, from 2019 to mid-2026, thousands of people worked together to construct 16.2 kilometres of tunnel beneath Auckland, creating critical infrastructure that will protect the city’s waterways and support future generations.

The NZ$1.66 billion project involved some of the most complex underground construction works ever undertaken in New Zealand, including tunnelling between 15 and 110 metres below ground, 17 construction sites and 19 shafts up to 75 metres deep.

The completion of the Central Interceptor was celebrated this week with a final project celebration in central Auckland, bringing together the people and partners who contributed to this landmark achievement. The celebrations concluded with the final blessing ceremony at the Māngere Pump Station, marking the official transition from construction to legacy.

The success of the project was made possible through the commitment and collaboration of thousands of people. More than 4,300 people attended the project’s two-day induction, with teams completing 90,020 training hours, engaging with 4,293 stakeholders and delivering 85 public events throughout construction. The project also prioritised environmental outcomes, with 97% of the 780,470 cubic metres of spoil generated diverted from landfill and 144 trees reinstated.

Now fully operational, the Central Interceptor will reduce wet-weather wastewater overflows by 80%, helping protect Auckland’s waterways and supporting more than 1.8 million people across the region.

The Central Interceptor was Ghella’s first project in New Zealand and has been an important milestone in our journey in the country. Building on the knowledge, expertise and partnerships developed through this project, Ghella is proud to continue delivering essential wastewater infrastructure in Auckland through the Herne Bay Collector project.

We congratulate everyone who contributed to the delivery of the Central Interceptor and thank Watercare, our joint venture partner Abergeldie, our employees, subcontractors, suppliers, consultants, mana whenua and the Auckland community for making this landmark project a reality.