Source: Auckland Council
Watercare’s Central Interceptor project has passed an historic milestone with the southern half of the 16.2 kilometre tunnel (Blockhouse Bay south to Māngere Wastewater Treatment Plant) going live. Watercare is now one step closer to the goal of cleaner waterways and beaches for central Auckland.
A formal event was held on 14 February at a new pump station in Māngere, attended by Minister for Local Government Simon Watts, Auckland Mayor Wayne Brown, politicians and project teams. Around 200 guests lined the pump station shaft as Mayor Brown gave an order to start up giant pumps sending wastewater flows from the Central Interceptor tunnel to the nearby treatment plant at a rate of 1,200 litres per second.
It was an historic moment during proceedings dedicated to recognizing the accomplishments of the 600-strong Watercare and Ghella Abergeldie JV Central Interceptor project team which began construction in 2019.
Watercare’s major new pump station has been built at Māngere Wastewater Treatment Plant to take flows from the Central Interceptor tunnel to the plant for processing.
Mayor Brown said that as an engineer himself, he appreciated the skills involved to achieve this outcome:
“It’s a significant milestone for Aucklanders and a huge engineering feat for the team who have been working for the past six years. I look forward to the Central Interceptor project being completed next year to fully realise the benefit, including an 80 percent reduction in wet weather overflows and improved water quality.
“This is an important piece in fixing Auckland’s infrastructure. The Central Interceptor will take pressure off other parts of the network and will allow other long awaited wastewater projects to progress” says Mayor Brown.
Watercare Chief Programme Delivery officer, Shayne Cunis says getting the southern half of the Central Interceptor tunnel up and running as quickly as possible was always the goal:
“This is a huge result. It is rare both globally or in New Zealand for major infrastructure projects to be delivered safely, economically and on time.
We are hugely proud of the tenacity and dedication of our team, in particular our construction partners, Ghella Abergeldie JV. We didn’t want to wait until the project was finished at the end of 2026 before getting the southern tunnel going. We’ve done that despite everything that’s been thrown against us, including the COVID-19 pandemic, major storm events and unprecedented inflation for modern times.”
The main environmental benefits (cleaner waterways) won’t however be realised until the remaining Central Interceptor tunnel (running from Mount Roskill to Herne Bay) is completed, along with new infrastructure such as the Herne Bay Collector, which is currently under design.
It’s northern central city suburbs such as Mount Albert, Grey Lynn and Herne Bay where major wet weather overflows occur into the likes of Oakley Creek, Meola Stream, Point Chevalier and Point Erin beaches.
The switch on of the southern tunnel does however mean improved resilience for Watercare’s wastewater network, says Shayne Cunis: “Aging infrastructure such as ‘Pump Station 23, Hillsborough was often overwhelmed by stormwater in big storms. Now the new Central Interceptor tunnel will capture these flows.
The Western Interceptor will also no longer carry flows under the Manukau Harbour, which is another win,” he says.
The Central Interceptor project forms part of Watercare’s $13.2b programme to deliver new water wastewater and infrastructure over the next 10 years to allow for future growth and a cleaner environment.
More information on the Central Interceptor is available via this helpful PDF [802KB].