Auckland’s Northern Interceptor is a new pipeline that redirects wastewater from the Hobsonville Pump Station to the Rosedale Wastewater Treatment Plant. Brian Perry Civil delivered a separable portion of roughly 2.5km of watermain and 1.5km of sewer rising main. The accelerated timeline meant the design was incomplete when construction started. The alignment changed soon after tender. Installing a 1200 dia. CLS pipe and numerous service ducts through a tunnel underneath SH16, down a 9m deep shaft, was a huge challenge – one that we self-performed safely and successfully, with the carrier pipe then installed by a subcontractor.

Most of the watermain was constructed via open trenching, within the public road reserve, with bored tunnelling for the section under the SH18 motorway. Key to the successful delivery was our ability to work collaboratively in a wider multidisciplinary team, provide constructability expertise, and self-perform large volumes of pipeline installation and associated complex civil works alongside and underneath SH18.