New Zealand-based water utility Watercare Services has started operations at the southern half of the 16.2km tunnel, a part of the Central Interceptor project in Auckland, New Zealand.
The tunnel connects Blockhouse Bay to the Māngere Wastewater Treatment Plant.
Watercare Services said the wastewater infrastructure project will improve the water quality in central Auckland’s waterways and beaches.
Recently, Auckland Mayor Wayne Brown inaugurated a new pump station in Māngere.
The pumps are designed to send wastewater flows from the Central Interceptor tunnel to the nearby treatment plant at a rate of 1,200 litres per second.
Mayor Brown said: “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% 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.”
The current milestone underscores the efforts of the 600 people from Watercare and Ghella Abergeldie JV Central Interceptor project, working on the construction since 2019.
Environmental benefits, including reduced wastewater overflows and improved water quality, will be realised upon completion of the remaining tunnel section from Mount Roskill to Herne Bay.
In addition, new infrastructure such as the Herne Bay Collector, will support the outcomes.
Northern central city suburbs, including Mount Albert, Grey Lynn, and Herne Bay, continue to experience significant wet weather overflows.
The overflows affect areas including Oakley Creek, Meola Stream, Point Chevalier, and Point Erin beaches.
The Central Interceptor is part of its $13.2bn project to deliver new water and wastewater infrastructure over the next ten years, said the water utility.
Watercare chief programme delivery officer Shayne Cunis said: “The switch-on of the southern tunnel does however mean improved resilience for Watercare’s wastewater network.
“Ageing 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.”
