Brynderwyn Hills recovery and enabling works

15 April 2024

Welcome to the latest update on the SH1 Brynderwyn Hills recovery works.

Great progress is being made in all work zones and we are moving closer to completing the major excavation work. You will have seen the extent of these earthworks in earlier updates.

This means we can focus on strengthening the downslopes (the underside of the road near the edge) and other areas, through stabilising methods such as retaining walls and piling. While these repairs may not be as visible from our drone photos or footage, they are critically important to the success of the project.

Manuka plant (left) and Manuka and Harakeke seedlings (right)

Grassroots approach to erosion control

Retaining walls and piling are not the only stabilising methods we are using. Hydroseeding involves a slurry of seeds, mulch and fertiliser being sprayed onto steep slopes to provide stability as well as helping to control dust, erosion, and sediment runoff. So far, we have used a whopping 185,000kg of mixed mulch and hydroseed within the closure.

We have mentioned this approach in earlier updates, and you’ve asked us about the seed combination used. The mix includes a variety of native species selected for their quick germination, resilience, and compatibility with the environment where they are being sprayed. For the Brynderwyns the varieties include: 

Species included in the hydroseeding mix 

• Leptospermum Scoparium (Manuka)                                            
• Coprosma robusta (Karamu)                                                            
• Poa imbecilla (Slender Poa)             
• Phorminum Tenax (Harakeke)

Creating space- what does this mean?

One of the key objectives of the project has been trying to prevent future weather issues causing lengthy closure of the Brynderwyn Hills. We have been creating space next to the existing lanes which will give our crews space in the future to do fixes, while still letting people travel on the road.

The photo above shows a shoulder space being created, on the left of the existing road.

Photos from the air and the ground

These 2 images give different views of zone C, a corner cut on the northern side of the closure.

The top image is a drone photo taken earlier this month and the bottom image was taken from the ground this morning. You can see how quickly the hydroseed mix is growing, with the hillside in the second image now covered in green.

Check out some of our key stats to date!

Team member profile

Meet Jahzyah Pumipi

Outside of the closure crews we’ve got a number of people connected to the project helping to make it possible for the road to be closed. One of those people is Jahzyah, who’s friendly and lively interactions with road users is making him popular with locals and visitors.

What is your role? My role is Traffic Controller for Traffic Management NZ. I keep road users safe and ensure they understand the need for me being on the road. I like to show my personality, to make them feel special and ensure they have a great day after seeing me.

What is your connection to the project? I’m a Dargaville local, having lived most of my life in Northland, I know how important this project is.

Why is this project special? As the Brynderwyns is the main connector route from Northland to Auckland, it is important for road users to be able to safety travel the quickest most efficient way possible.

Where is your favourite place in Northland? Waipu Forest, as it has a spiritual connection to my whanau.

Tell us something about yourself Whanau are a huge part of my life, I even work side by side with some of them. I enjoy gaming, relaxing and listening to music. I don’t have much spare time as I love my job, so would rather be setting up the work site, or operating stop/go paddle. That’s my happy place!

Key information at a glance

SH1 Brynderwyn Hills closed: 3 April (12:01 am) - 12 May (11:59 pm)

SH1 Brynderwyn Hills reopens: 13 May (12.01 am)

Three scenic detour routes

• Cove Road route: Turn off at Kaiwaka, use Kaiwaka Mangawhai Road, Garbolino Road, Tara Road, Cove Road, Nova Scotia Drive and connect back to State Highway 1. (Restrictions are in place for trucks with trailers on Cove Road between Mangawhai Heads Road and McLean Road).
• Paparoa Oakleigh Road route: Trucks and trucks with trailers up to 50 tonnes can use this route.
• SH12/SH14 route: HPMV (high productivity motor vehicles) must use this route.

Local routes contact:

Whangarei District Council 0800 932 463

Kaipara District Council 0800 727 059

State Highway route contact:

NZTA 0800 444 449

More information

For more information on the SH1 Brynderwyn Hills project, contact us at northlandproject@nzta.govt.nz

Visit the project website www.nzta.govt.nz/brynderwyn-hills