Project Description

Wairau Road Rising Main, Auckland

Project Owner: Watercare NZ
Project Head Contractor: March Cato Civil Engineering Contractors
Project: Supply of 682m HOBAS CC-GRP Pressure Jacking Pipe

The Wairau Pump Station located in the Wairau Valley, north of Auckland is located in challenging terrain in the middle of a commercial and industrial area. Microtunnelling at a depth of 5.5m was required under one of Auckland’s regional arterials which carries approximately 12,000 commuters a day. The new sewer main replaces an existing wastewater rising main installed in the 1960s and is part of an Auckland wide upgrade of wastewater infrastructure by Watercare.

This project was originally planned to take place in 2014 using HDPE and directional drilling as the main form of installation. March Cato and Watercare realised this methodology and pipe material choice on a busy road just off the Northern Motorway would be problematic. March Cato sourced an alternative construction option to better suit the project – the new proposed method would be to use HOBAS CC-GRP Pressure Jacking Pipe supplied by Global Pipe and a Herrenkneckt Tunnel Boring Machine. In doing this, launch shaft and receiving pits could be isolated to areas where there would be no need to shut down road access for cars.

Global Pipe provided full technical support and supply of all Hobas pipe during the project. This was the first time HOBAS CC-GRP Pressure Jacking Pipe was used in New Zealand. This enabled Watercare to deliver a solution for the problems faced at Wairua Road Rising main with significantly less disruption during construction.

The first two jacking pipe drives took place ahead of schedule. The project is planned to be completed by October 2018.