You may wonder (as I really did) what the giant machines are doing on Greenhithe Road. Here is some info from the construction office:

Horizontal directional drilling (HDD) is a trenchless construction method for the installation of underground pipelines. This method is controlled from the surface and the tunnel follows a predefined route.

The drilling already commenced in July, expected to be completed at the end of 2019.

  • Three separate pipelines are being installed: One 200 millimetre diameter line for circulation of drilling fluid during construction and for fibre cables post construction; two 500 millimetre diameter wastewater pipelines.
  • Over the construction period there will be increased truck movements to and from both the entry and exit points. These being the northern end of Wainoni Park, Greenhithe and North Shore Memorial Park, Schnapper Rock
  • It is a mostly continuous process with extended hours of operation required during the pulling of the product pipes.

Read the letter below from Watercare for more details.

Northern Interceptor Watercare Project Update July 2019Download