O Mahurangi – Penlink

9 September 2022


O Mahurangi Penlink Project Update

Kia ora koutou,

As the team have been progressing the design over the past three months, we’ve enjoyed getting out and about meeting people in the local community.

We had a great turn out to our Whangaparāoa open days and look forward to seeing those that can make it to our Stillwater community information day on Sunday 11 September. Once again, we’ll be there to answer any questions and gain your feedback on the refined design.

A range of questions have already been asked at these drop in sessions, and you can find answers to these, as well as lot more, further down in this newsletter and on our website here.

Geotechnical investigation work has recently begun around Ara Weiti Road and will be continuing throughout the alignment, in Duck Creek Road and Archers Block next week. Keep reading to see what we have discovered so far.

We’ve also been busy carrying out investigations for unexploded devices - keep reading to see what we have discovered so far.



Whangaparāoa community information days

A huge thank you to everyone who came along to our community information days held on Wednesday 10 and Saturday 13 August at The Archer in Whangaparāoa.

Nearly 200 people joined us over the two events to ask questions and talk to the project team. It was great to see such a good turn out, showcasing how interested and engaged the local community is with the project.



Key questions raised at the information days

What's the timeframe?

  • Geotechnical investigations are underway and early construction works will start in late 2022. This will include clearing ground, establishing access tracks and points and temporary erosion and sediment controls, early earthworks, office setup and starting construction of a temporary access platform within the Weiti River to enable the bridge construction.
  • Bulk earthworks are set to start in late 2023.
  • The project is expected to be completed at the end of 2026.

What changes have been made to the Whangaparāoa Road intersection design?

  • The key design change is that instead of joining Whangaparāoa Road at a cross road with Beverley Road, the Penlink road will now continue further to the south to flow into the existing Whangaparāoa Road near the New World supermarket.
  • This will be the part used by people travelling towards or from the Gulf Harbour-end of the peninsula.
  • For people joining or exiting O Mahurangi - Penlink from the northern/Red Beach end of the peninsula, a short new section of Whangaparāoa Road will be built offline to the west.
  • When O Mahurangi - Penlink is open, this section of Whangaparāoa Road will connect to it at a T-intersection with traffic signals.
  • This updated design saves the quieter Beverley Road from disruption and a part of the big O Mahurangi - Penlink intersection.


Who is in the O Mahurangi - Penlink alliance?

  • The project alliance is made up of Waka Kotahi NZ Transport Agency, Fulton Hogan, HEB Construction, Aurecon and Tonkin + Taylor. Alliances have worked well for delivering projects in the past and we love the collaboration of working in a team.
  • In addition, we are working very closely with our iwi partners on this project.

Why has the design been refined?

  • The alliance have refined the design to bring better outcomes for the environment and community.
  • The Whangaparāoa Road intersection is now planned to be built ‘offline’ on Crown owned land within the Cedar Reserve, avoiding more disruption to the community.
  • This means that during most of the construction time motorists, cyclists and pedestrians can continue to use Whangaparāoa Road how they do now.
  • Less concrete will be used to build the Wēiti river bridge which means lower construction emissions.

Where did the name O Mahurangi come from?

  • The name O Mahurangi was gifted by our iwi partners on the day the Project Alliance Agreement was signed.  
  • The name O Mahurangi is in recognition of the ancestor Mahurangi, a tohunga (priestess) who lived in Hawaiiki and whose powers are said to have enabled the construction of the great voyaging waka Tainui.
  • When Tainui waka arrived at what is now known as Wenderholm Regional Park in around 1200, they gave the name Mahurangi to a small island adjacent to the Maungatauhoro headland. The island’s name gave rise to the harbour in which it sits, and eventually to the wider district and the Crown’s land purchase. 

How will flooding be managed?

  • Stormwater wetlands will be made to collect and treat stormwater run-off from the O Mahurangi Penlink and Whangaparāoa Road surfaces and reduce the risk of flooding in this area.
  • The new design will allow the Whangaparāoa intersection to continue operating during a one in 100-year flooding event.
  • The wetland areas will feature ponds, landscaping and pathways.

More FAQs can be found on our website.



Unexploded device investigations

A couple of weeks ago, the project team carried out an investigation for unexploded devices (due to the Americans using the area for target practice in World War II).

The investigations took place on the south east corner of East Coast Road & Ara Weiti Road intersection and approximately 1.4 hectares were searched and cleared.

We found 11 horseshoes, numerous lengths of wire, some short lengths of chain, a couple of star pickets, and the tail of a mortar.



The mortar tail found during investigations



Geotechnical investigations

We’ve also recently begun geotechnical investigations along the main alignment.

These are the latest in a series of investigations carried out over several years to gain information about the soil and rock that will provide the foundations and earthworks supporting the project.

A wide range of geotechnical investigation and interpretation techniques are being used including machine boreholes with core recovery, Cone Penetration Testing, hand augered boreholes, inspection pits dug by excavator, geophysical testing in boreholes, surface geophysical surveys and surface mapping by engineering geologists.

The latest investigations being carried out are important because they will directly inform the detailed design of structures and earthworks on the O Mahurangi - Penlink project.



Geotechnical investigation team on site on Ara Weiti Road



A birds eye view

Some of our team members recently took the opportunity to see things from a different perspective, taking a helicopter ride along the O Mahurangi - Penlink route to get a better understanding of the landscape.

It was a timely reminder of how stunning the wai (water) and whenua (land) is that we get to work on.