The Central Interceptor is a $1.2 billion wastewater tunnel proposed to run between Western Springs and the Mangere wastewater treatment plant (WWTP).

The project is needed to ensure there is sufficient capacity in the network to meet planned population growth and development in Auckland, provide a more resilient wastewater system, and provide an initial remedy to historic wet weather discharges in central Auckland.

The main tunnel will be approximately 13 kilometres long and will lie between 15 and 110 metres below the ground surface and will cross under the Manukau Harbour approximately 15 metres below the seabed. The main tunnel is anticipated to be excavated by Earth Pressure Balance TBM. It will have an internal diameter of 4.5m. Two separate Link Sewer tunnels, 3.2 and 1.1 kilometres in length and constructed by pipe jack methods, will connect into the main tunnel. Drive lengths range from 300 to 960 metres between shafts.

Auckland Council's water utility body Watercare will work with infrastructure firm Ghella Abergeldie Joint Venture to deliver the project by 2025.

So far, Asmuss has been engaged to import and supply:

  • 1127m 1400mm Special grade polyethylene pipe
  • special fabricated PE fittings:
  • 34 x 1400mm stub flanges
  • 22 x 1400mm x 45 bends
  • 2 x 14000nn 22 bends
  • 10 x 1400 x 450mm Special tees
  • 8 x 1400mm special offsets

To find out more about this and other projects, contact us now.