SH1 Brynderwyn Hills recovery and enabling works

17 June 2024

Freshly applied asphalt is rolled in zones H to J

We know anticipation is building for the planned reopening of SH1 Brynderwyn Hills at the end of June. In our last update, we mentioned that while the slip was being cleared, significant progress was made in other areas as well.

This week our team will be focusing on laying the remainder of the asphalt on the newly created shoulder, followed by line marking and installing the guardrail.

With the slip cleared, we now have direct access to the retaining wall located opposite the area where the earth had come down. This will allow us to proceed with the necessary stabilisation work to ensure the road’s safety and reliability.

Thank you for your patience and continued support as we work towards the reopening. We will provide an update on the exact opening date soon.

Specialist equipment – remote controlled bulldozer

Our remote controlled bulldozer is now hard at work removing a small knoll from the hillside.

This very clever little piece of machinery allows us to carry out work in a steep environment without the need to have a person operating it from inside the dozer. It is operated from a safe distance via remote control and is secured to a winch further up that automatically detects either up or down movement and adjusts its pull accordingly.

This demonstrates our commitment to keeping our people safe and putting people at the heart of everything we do.

The remote bulldozer working on top of zone E, in the distance and close up.

Work that will take place after reopening

Once the road reopens, you’ll notice there will be some ongoing work in the corridor behind temporary steel barriers.

Work that didn’t require a full closure has always been planned to take place using the newly created shoulder space. Before the slips in late April, we expected this would take a period of 8-12 months. Making the most of the extended closure time we have accelerated these works putting in soil nails, piles and anchors in zone E and completing the retaining wall in zone F. As a result we have shortened this time down to 4-6 months.

An example of some of the works you will see happening in the shoulder behind a barrier include:

• installation of additional guardrail 
• drainage work on the down slope side
• planting on the uphill side in all zones
• additional hydroseeding along the berms in zones A and B
• downslope works in zone D using shotcrete and rock anchors
• infill concrete between channel drain and earth in all zones.

A final asphalt layer will also be put down across the whole width of the road. We must wait until the weather is warmer and drier to lay this final coat to ensure its quality and durability.

The images below show anchors and soil nails being installed at zones E and H.

Key information at a glance

SH1 Brynderwyn Hills closed: planned reopening end of June 2024

Three scenic detour routes available:

• 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 our website www.nzta.govt.nz/brynderwyn-hills