For the first time, tunneling has begun under a major harbour in Tāmaki Makaurau. It's part of Watercare's giant waste water tunnel, which is expected to make the city's polluted beaches a thing of the past.
And burrowing for 1.5km under the Manukau Harbour is the most challenging part of the 15 kilometre project.
Reporter Louise Ternouth and camera operator Marika Khabazi went underground to check it out.