Otahuhu East Branch Sewer


Watercare Services Ltd

Client Project Manager

Roy Schultz

Engineer to the Contract

Tim Munro

Engineer’s Representative

Ken Chung

Design Engineer

Harrison Grierson


The project involved the installation by directional drilling of a twin siphon (250OD & 200OD HDPE) pipelines under the Tamaki Estuary, construction by microtunnelling of a 300NB pipeline and associated precast and insitu concrete chambers.

A new pipe bridge spanning 60m across the Tamaki Estuary required construction of a temporary working platform across the mangroves to provide access for piling rigs and pipe installation.


  • Insitu concrete chamber construction
  • directional drilling (siphon)
  • microtunnelling
  • HDPE welding
  • piling
  • drainage