Auckland is set to reap the environmental benefits of Watercare\u2019s Central Interceptor\u00a0wastewater tunnel, which is now fully operational.<\/p>\n
The $1.66 billion project\u2014New Zealand\u2019s largest-ever wastewater infrastructure\u00a0investment\u2014will dramatically reduce wet weather overflows, improve the health of<\/p>\n
Auckland\u2019s waterways and harbours, and support growth across the region for decades\u00a0to come.<\/p>\n
The Central Interceptor has already delivered significant environmental benefits. The\u00a0southern half of the tunnel went live in early 2025, preventing an estimated 741,000\u00a0cubic metres of wastewater and stormwater from overflowing into the environment by 1\u00a0July this year. That\u2019s the equivalent of almost 300 Olympic-sized swimming pools.<\/p>\n
\u201cThe Central Interceptor provides the backbone for future projects that will further\u00a0improve environmental performance, increase network resilience, and support\u00a0Auckland\u2019s growth,\u201d says Watercare chief executive Jamie Sinclair.<\/p>\n
The first of these projects, the Herne Bay Collector, is under way \u2013 a wastewater tunnel\u00a0that will connect to the Central Interceptor when completed and contribute to further\u00a0reducing wet weather overflows.<\/p>\n
Sinclair says the completion of the 16.2-kilometre Central Interceptor tunnel is a\u00a0transformative moment for Auckland.<\/p>\n
\u201cThe Central Interceptor is a game changer for our city that will deliver lasting\u00a0environmental, community and growth benefits for Aucklanders.”<\/p>\n
\u201cThis project is at the heart of our commitment to improving water quality across the\u00a0region. Bringing together world-class engineering, long-term planning and strong\u00a0partnerships, it delivers benefits for Aucklanders now while enabling a new generation\u00a0of projects that will further reduce wastewater overflows and make a real difference to\u00a0the health of the Waitemat\u0101 Harbour and other waterways into the future.\u201d<\/p>\n
Running from Point Erin in Herne Bay to the M\u0101ngere Wastewater Treatment Plant, the 4.5-metre-diameter tunnel sits between 15 and 110 metres below ground and passes beneath the Manukau Harbour. Together with its link sewers in Mt Roskill, Blockhouse Bay and Mt Albert, it captures and transfers wastewater and stormwater flows that would otherwise contribute to wet-weather overflows.<\/p>\n
With the northern section now in service, the full tunnel is operational and positioned to deliver even greater environmental improvements across the city.<\/p>\n
Mayor Wayne Brown, who is also an engineer, says the completion of the project is a significant achievement that will benefit Aucklanders by reducing wet weather overflows and helping to improve the health of our harbours and local streams.<\/p>\n
\u201cThis is Auckland\u2019s largest wastewater infrastructure project, taking seven years to complete using a tunnel boring machine to build the gravity-driven tunnel across the isthmus between M\u0101ngere in the south and the central city,\u201d says Mayor Brown.<\/p>\n
\u201cAucklanders want cleaner waterways and to be able to enjoy the likes of Browny\u2019s pool, local beaches and marine environment.”<\/p>\n
\u201cDelivering these outcomes while creating a smarter, more resilient network is exactly what we are committed to providing for the future of Auckland. This project shows what’s possible when we invest in the right infrastructure at the right time.\u201d<\/p>\n
The project’s successful delivery also reflects the power of collaboration between Watercare, delivery partner the Ghella Abergeldie Joint Venture, mana whenua, Auckland Council and local communities.<\/p>\n
Construction began on the project in 2019. Despite challenges including the Covid-19 pandemic, major weather events and unprecedented inflationary pressures, the team delivered the project on schedule and close to its original budget.<\/p>\n
\u201cMega projects of this scale rarely stay so close to programme and budget, particularly given the challenges faced throughout delivery,\u201d says Sinclair.<\/p>\n
\u201cWorking together has enabled one of New Zealand’s most complex infrastructure projects to be delivered safely, efficiently and with a strong focus on environmental and community outcomes. We\u2019re incredibly proud of what has been achieved.\u201d<\/p>\n
An event will be held today <20 July> celebrating the Central Interceptor being fully operational, and a karakia whakamutunga, or final blessing, will be held tomorrow morning to complete the project. Central Interceptor facts and figures<\/p>\n
The Central Interceptor wastewater tunnel is 4.5 metres in diameter and 16.2 km long, running from the M\u0101ngere Wastewater Treatment Plant to Point Erin in Herne Bay.\u00a0
\nIt had 17 construction sites across Auckland.
\nThere are 19 shafts in total.
\nSince construction began in 2019, more than 4,300 people have worked on the project.\u00a0
\nThe tunnel has the capacity to hold 299,000 cubic metres of wastewater and stormwater.
\nThe giant tunnel boring machine, Hiwa-i-te-Rangi, which created the main tunnel, was named by school students after the youngest star in the Matariki cluster, which symbolises growth and prosperity. She was 190 metres long and weighed 740 tonnes.
\nHiwa-i-te-Rangi was electric, as were the locomotives used in the tunnel to remove the spoil to replace diesel and reduce fuel use.<\/p>\n
About Watercare<\/p>\n
Every day, we supply about 440 million litres of safe drinking water to 1.7 million people\u00a0in Auckland. We also collect and treat their wastewater.\u00a0Over the next 10 years, we will carry out more than 1000 projects to improve and expand\u00a0our water and wastewater infrastructure\u2014investing an average of $3.8 million every day ($13.8 billion in total).\u00a0Our infrastructure investment programme will help to keep our precious environment\u00a0healthy by reducing the frequency of wastewater overflows onto land and into\u00a0waterways.<\/p>\n","protected":false},"excerpt":{"rendered":"Auckland is set to reap the environmental benefits of Watercare\u2019s Central Interceptor\u00a0wastewater tunnel, which is now fully operational.…\n","protected":false},"author":2,"featured_media":537793,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[111,43,139,69],"class_list":["post-537792","post","type-post","status-publish","format-standard","has-post-thumbnail","category-new-zealand","tag-new-zealand","tag-news","tag-newzealand","tag-nz"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/537792","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=537792"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/537792\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/537793"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=537792"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=537792"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=537792"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}