Victoria, the smallest of the three TBMs building the new wastewater system, broke through into a shaft at Mt Roskill this week. She was launched 18 months ago to build a wastewater and stormwater pipe that will connect to the 16.2km Central Interceptor wastewater tunnel.

The pipe TBM Victoria built will allow for a major housing development in the area and reduce wet weather overflows into local beaches and waterways.

In March, micro TBM Domenica made the final breakthrough on the 3.2km link sewer tunnel. She is now being refurbished before starting work on link sewer B in late July. This link will be just over 1km long and involve two separate drives.

The Central Interceptor’s main TBM, Hiwa-i-te-Rangi, was launched in August 2021 and has completed 11.3km of the bore towards central Auckland and laid 7068 rings. 

In late May, funding was confirmed to extend the Central Interceptor by more than 1km.

Ghella Abergeldie Joint Venture (GAJV) is carrying out the works.

The Central Interceptor is the largest wastewater project in New Zealand’s history and the country’s largest bored wastewater tunnel. It will store 226,000m3 of wastewater, control the flows into treatment plants and reduce the number of wastewater overflows.