July 2026

In the past few months Brian Perry Civil (BPC) have completed the backfill of the pipeline after it was pulled into position. This was completed with a barge and long reach excavator fitted with Global Positioning System (GPS) instrumentation and software. Earth Sciences New Zealand’s vessel RV Ikatere was used for bathymetric surveying and this information was loaded into the excavator’s machine control software so the operator knew where to place the backfill material. It also enabled a protective virtual “halo” to be placed around the pipe which prevented the excavator bucket from hitting the pipeline by locking out the excavator controls.

The seawall has also been reinstated with the original armour stone that was removed and stockpiled as well as additional armour to ensure that the consent condition that the seawall was reinstated to accepted industry practice has been met. A key challenge during these works was the presence of kororā (little blue penguins) who were coming ashore and looking for areas to nest. Z Energy engaged an ecologist who together with a Department of Conservation (DOC) approved wildlife detection dog and her handler, undertook a sweep of the construction site every morning during the seawall reinstatement to ensure that no kororā would be harmed.

In early July, BPC lifted in and connected the section of pipe known as the riser. The riser connects the subsea pipe to the wharfhead pipework. To determine the dimensions of the riser, a Remotely Operated Vehicle (ROV) fitted with high resolution cameras was used to photograph the end of the pipe, the seabed, and the wharf pile that the riser attached to. These images were then processed in software to develop a millimetre accurate 3D model via a process known as photogrammetry. The riser was then designed to suit the physical dimensions and fabricated by Energyworks (the mechanical contractor on this project). The riser was lifted into position utilising BPC’s jack-up barge Manahau with a crane on deck. Once lowered into position, divers from Underwater Solutions connected the riser to the end of the pipe and into riser guides on the wharf pile. This was a significant milestone for the project and Z wishes to pass on our sincere thanks and admiration to the contractors for the safe, professional, and highly skilled manner in which this critical activity was undertaken.

For the remainder of July, works will focus on the wharfhead and foreshore pipework with a view to undertaking cutover and tie-in during August. This is the process of tying the new pipeline into the existing pipeline along the Seaview Marina foreshore. Once this is completed future discharges will then flow down the new submarine pipeline.

Demolishing the existing pipeline and disestablishing the site will then occur with a view to being completely off site before the end of the year.

We have started discussions with Hutt City Council (HCC) regarding the completion of the final section of the Tupua Horo Nuku shared pathway project. This is to ensure that as we disestablish the site and HCC start their project, that we do this in a coordinated manner and that access through the Point Howard headland is maintained for pedestrians and cyclists.

Image 1 – Riser in position before being lowered onto seabed.

Image 2 – backfill being placed over the pipeline by barge and long reach excavator.

Image 3 – Aerial image of reinstated seawall and partially constructed riser of staging wharf.