Central Interceptor

A super-sized wastewater tunnel that will reduce overflows

Construction of the Central Interceptor is well underway

Over the next six years we’re building the Central Interceptor tunnel to help make Auckland's waterways cleaner. The Central Interceptor will run underground from Grey Lynn to our Māngere Wastewater Treatment Plant. It will have several link sewers and shafts along the route for collecting and transferring wastewater into the tunnel.

Our contractor Ghella Abergeldie Joint Venture (GA) is building the Central Interceptor. GA has more than 150 years’ experience with tunnelling and wastewater projects of this size across the globe.

Once completed, the tunnel will be 14.7 kilometes in length, the longest in New Zealand. At 4.5 metres in diametre, it will be high enough to fit a giraffe and wide enough to fit four rhino side by side.

To find out more about the project, click here to watch our video and see how the Central Interceptor will make Auckland a better place to live.
Benefits to you

Benefits to you

Find out how the Central Interceptor will benefit your community. 
Staff check the equipment at a water treatment plant

Community events

Information about our community days and education programme 
Consent Documents

Consent Documents

All the consent documents associated with the project. 

FAQs

Our answers to frequently asked questions associated with the project. 

Key facts

All the facts and figures about the Central Interceptor project. 

Meet the team

Get to know the people who are working on New Zealand's longest tunnel. 

News

All the latest news, newsletters and media clippings about the project. 

Our sites

Find out what's happening at our sites across Auckland. 

Progress in pictures

A picture gallery of the project as it takes shape. 

Keep up with us on social media

Facebook: WatercareNZ
LinkedIn: Watercare Services Limited


You never know what you’ll find when you start digging 30-35 metres underground, particularly when the area you’re excavating used to be seabed. Our Central Interceptor team and contractor Ghella Abergeldie JV are currently excavating along the route where tunnelling for New Zealand’s longest wastewater tunnel will kick off in April/May. Recently, the team dug up some true gems including a 3-4 million year old cockle – Maoricardium spatiosum. If that’s not impressive enough, a prehistoric whale vertebrae believed to be from a Baleen Whale was also unearthed. So far 82 fossil species have been found and identified.