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Central interceptor tour Future-Fit Aotearoa

Central interceptor tour Future-Fit Aotearoa

Hear about how the longest wastewater tunnel in Aotearoa, the Central Interceptor, is designed and built and how it contributes to our economy. We caught up with Watercare’s engineering manager, Stephen Grace, to find out more.

Why should people attend your tour?

It’s the biggest, most expensive tunnel infrastructure project in New Zealand. Not only will it improve the resilience and environmental performance of our wastewater network, but it’s also 14.6km long and 15 metres below ground!

The tunnel will help make Auckland waterways cleaner. With a 200,000m3 capacity, the tunnel is excavated by a tunnel boring machine to an internal diameter of 4.5 metres. Two separate link sewer tunnels ranging from 2.0 to 2.5 metres internal diameter and 1.1 to 3.2 kilometres in length will be constructed by pipe jacking. 16 shafts and connecting sewers up to 78m deep will divert flow into the tunnel.

What do you find most enjoyable about the project?

Finally, seeing the project built after nearly 12 years of involvement. My initial exposure was back in 2009, but I came full-time on to it in 2014. So seven years later, we are full steam ahead on building this project.

What has been the most complex challenge of the project for you?

Maintaining the project design intent whilst adapting to change – every new person wants to redesign it without the full context of why things have evolved the way they have. But also Watercare continues to develop, and we cannot be blind to new ways of doing things.

What other benefits will the tunnel provide?

The project will provide a platform for career development for many young and developing engineers and support staff. At the same time, it will facilitate Auckland’s growth and resolve many legacy wastewater and stormwater issues.

What types of people do you lead?

I work with various disciplines, from civil and structural engineers to control systems and environmental. It requires a broad skill set, and I am constantly learning.

Tour details:

  • Time: 10.15am – 11.45am
  • Location: Cordis Hotel
  • Spaces unlimited

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