Project update - May 2025

Tēnā koe and welcome to the Northland Corridor newsletter.

It’s been another busy month for the Northland Corridor team as we continue to work at pace across the project. We are progressing with procurement and site investigations for Ara Tūhono – Warkworth to Te Hana.

North of Te Hana the team are working on design investigations between Te Hana and Whangārei to refine the emerging preferred corridor into the preferred route. We have also been busy sending out letters to let property owners know they are in the emerging preferred corridor. We anticipate all letters should arrive by mid-June. Read on for more information for landowners.

The project team will be spending some time in the community in the coming weeks to share information on the project’s progress and answer any questions you may have. Read on for where you can find us.

Thank you to everyone who has taken the time to contact us since we announced the emerging preferred corridor in April. There have been some common themes coming through, so in this edition of the newsletter we’ll answer some of these questions below.

What if I can’t make the information sessions?

We know everyone is busy, so if these dates and times don’t work for you and you’d like to talk to us, feel free to reply to this email or contact us on [email protected]

FAQs

Why can’t you just put a tunnel through the Brynderwyn Hills?

We looked at all options when choosing the emerging preferred corridor for the Brynderwyn Hills, including a tunnel. Tunnels can be very expensive to build, maintain and operate. They also come with restrictions such as a fixed width (no option to widen later) and restrictions around the type of goods that can be carried through them, such as certain types of fuel and gas.

A tunnel through the Brynderwyn Hills would be very long and although a tunnel is technically feasible it would take a lot longer to build and would be prohibitively expensive.

The geology in the area has some challenges, but we think the emerging preferred corridor we have selected will allow us to build a new road faster and more cost effectively with less long term damage to the environment.

Why isn’t the Brynderwyn Hills alternative being built first?

Although the Brynderwyn Hills alternative is a key priority, the Ara Tūhono - Warkworth to Te Hana section of the corridor is the most advanced, therefore physical works are able to begin earlier than the other sections of the corridor.

The completion of the Warkworth to Te Hana section will resolve the critical resilience challenges in the Dome Valley.

Before construction can begin on the Brynderwyn Hills alternative, significant preliminary work including geotechnical investigations, route selection, property acquisition and consenting is required. The preliminary work for this section will be undertaken in parallel to the procurement and construction of the Warkworth to Te Hana section and we have a dedicated team working on this.

When will we know where the road will go?

We are working at pace to refine a design for the new road within the emerging preferred corridor and expect to be able to share a preferred route in August/September this year.

The timeline below shows our next steps over the coming months. Click here to view a larger version of the project timeline.

Update for landowners in the emerging preferred corridor

All letters letting property owners know they are in the study area for the emerging preferred corridor have now been sent. We anticipate these should all arrive by mid-June.

To help us contact landowners more quickly and efficiently we are asking those that receive a letter to register their phone number and email address with us and confirm who the main point of contact is for their property. Details about how to register contact information is in the letter.

Our next steps are to refine this study area into the preferred route. To help us do this a range of site investigations such as geotech, ecology, archaeology and cultural assessments will need to be carried out along the corridor. To undertake some of these investigations we will need to access private property.

If we need to carry out an investigation on your property it does not necessarily mean your property will be affected by the project or need to be purchased. We won’t be able to confirm that level of detail until the preferred route has been approved by the NZTA Board in August/September 2025

If you have any questions, please contact us by emailing [email protected] or phoning us on 0800 927 293.

PPP Procurement update

The team have been working hard to evaluate the submissions made during the Expression of Interest (EOI) phase, which closed on 2 May 2025. The next step is to select a shortlist from the applications received during the EOI phase who will then be invited to participate in the Request for Proposal (RFP), which will be issued by the end of June 2025.

Ecology surveys update

We have been carrying out a range of site investigations and surveys along the route for Ara Tūhono - Warkworth to Te Hana including geotech, surveying, archaeological and ecology. These investigations help inform the design for the new road.

One of the key activities we have been busy doing is ecological surveys throughout forest and bush areas within, or close by, the project’s designation (or footprint). These surveys help us understand any impacts on the environment and how we can mitigate them.

Freshwater surveys have been undertaken to determine and map ecological features such as streams and wetlands within these areas and land surveys have been targeting potential habitats for important animals and insects that may be living there. To date, we have carried out more than 30 ecology surveys along the 26km route.

The team collects eDNA through a device placed in a fast-flowing stream section. After a day, the sample is sent to the lab to identify species in the area.

Meet the team

Michaela Scarrott – Ecologist

I have surveyed and been involved with ecology (land and some freshwater) along the new route for Ara Tūhono - Warkworth to Te Hana.

Tell us about yourself and your role:

I’m passionate about protecting our native wildlife and their habitats. A main part of my role as an ecologist for this project is to assess the effects of construction on our native species and find solutions to manage any adverse effects that my occur.

My days are never the same. Some days I am hiking though native forest surveying birds, or out at night searching through the leaf litter looking for Archie’s frogs. I might be found crawling into burrows during the day looking for kiwi, monitoring wetlands, or in the office reviewing spectrograms to find bats.

What excites you about the Ara Tūhono – Warkworth to Te Hana project?

Much of the forested and unforested areas are remote, and have not been previously surveyed, so it’s exciting to survey these spaces as we never know what we’re going to find on a given day. There are challenges involved with large scale projects, and I’m looking forward to helping find the best outcomes alongside all other teams involved.