KGA Geotechnical Group Ltd

The Hunua 4 project is one of the largest water pipeline projects to be undertaken in New Zealand.

It consists of 24km of 2m diameter pipeline installed via open trenching methods.

KGA provided geotechnical services for the construction of the pipeline and ongoing contractor support during its installation. Construction challenges included variable ground conditions, from soft peat to volcanic tuff and basalt rock, and a high groundwater table with considerable water flow. The pipeline installation also had site constraints such as underground and overhead utility services and site works within a high density residential area.