SH16 Brigham Creek to Waimauku

25 November 2025

Stormwater culvert replacement works

November 2025 – Project Update

Tēnā koe and welcome to our penultimate construction update for Stage 1.

A huge thank you to our neighbours for their understanding and patience as we progress this essential work. We are still on track for project completion in the first quarter of 2026 with the final road surface works scheduled early in the new year! You'll be interested to know the asphalt we're using is open-graded porous asphalt which is a type of road surfacing material that allows water to drain, reduces traffic noise, and improves skid resistance. This means you'll have a smoother, quieter ride on the new road. 

We're also looking forward to re-opening the Matua Road and SH16 intersection to left in, left out traffic prior to Christmas. For everyone’s safety, please continue to keep to the left and the 60 kph speed limit.

This Saturday 29 November from 2pm-4pm we’re holding a Community Open Day at the Small Hall at the Kumeū Community Centre.  Come along to meet the team and learn more about the project. We’ll have information on the final works for Stage 1 (Huapai to Waimauku) and Stage 2 (Brigham Creek to Kumeū).

We've lots of information to share this quarter including an update on Stage 2 of the project at the end of the newsletter.

Construction update; what’s news with the crews?

Night paving works, shifting traffic onto new permanent lane alignments, and a culvert in need of urgent replacement have been some key features of our works in the last few months. All of this plus landscaping, mulching and fencing have transformed the busy 3.1km site into a closer picture of what the highway will look like when works are completed.

We again want to thank the Rodney Local Board for their continued support.   And to our daily commuters – our crews and their families are so very grateful to you for continuing to make the site safer by keeping to the speed limit.

For more information on the project please see our webpage.  If you’d like to receive construction updates, please use our contact details below.

Stormwater culvert replacement

Recent service investigations revealed the above stormwater culvert’s condition required urgent attention before final road surface works could commence. Not part of the original project scope, traffic had to be diverted for 36 hours to replace the culvert postioned 4 metres under the highway. 

Culverts are channels that help guide water away from a road and to a waterway, reducing the risk of flooding and damage to the road in bad weather as well as erosion over time.

Project teams with multiple machines worked non-stop in difficult ground conditions to ensure the highway was reopened ahead of peak traffic the following Monday morning.

Here is a video of the works in action.

New retention swale east of Kumeū 2 Bridge

Building the new retention swale shown above and below, has required significant planning between the site team, designers and service providers.

Like all swales, it catches rainwater from the road and helps clean it. The difference with this new design is that small 'check dams' (the raised sections) slow the water down, so dirt and grit can settle in the swale instead of washing straight through. A storage layer beneath the planted swale also holds water. Together, the slowing and temporary storage lets some water soak back into the ground, and the rest is released to the stream more gradually, reducing stress on the stream and supporting a healthier habitat for fish and other aquatic life.

Here’s what we’ve achieved August to November 2025

In August:

• completed Trigg Rd turnaround bay
• progressed the retention swale, and pavement and landscaping works
• carried out night works to complete private driveway excavation and reinstatement. In one case – works that would've taken over a week to complete during the day were completed across one large night shift with 2 earthworks crews.

In September:

• completed a traffic switch onto the final road alignment between Waimauku and 623 SH16
• on the back of critical fibre service diversions we made great progress with landscaping, kerb, channel, and driveway reconstruction works to enable placement of temporary steel barriers in advance of structural asphalt works.
• wet weather enabled landscape planting to continue with this being mostly completed across the site leaving minimal areas to be filled in. This work is now planned for the 2026 planting window.

In October:

• completion of works on the southern side of the carriageway east of the K2 Bridge to Coopers Creek, allowed a second traffic switch to be completed in the month, and our team returned to the northern side of the highway to complete the remaining verges, maintenance bay, kerb and channel, and pavements
• urgent stormwater culvert replacement works was added to the scope and the team quickly established a lay down area and implemented environmental controls - the existing stream was diverted and an eel was relocated! The ground was stabilised to create a working platform for machinery
• other additional works included 4 intensive nights of road rehabilitation paving at the Factory Rd intersection.

Looking ahead – what’s the focus for the next quarter: December to March 2026

• Open the Matua Road and SH16 intersection to left in, left out traffic prior to Christmas.
• Complete off-road emergency culvert replacement works at 623 SH16.
• Complete road widening between 601 – 619 SH16.
• Remaining structural asphalt pavement rehabilitation between 601 – 619 SH16.
• Asphalt surfacing remediation prior to the final asphalt layer.
• Final open graded porous asphalt surfacing throughout the site Factory Road to Station Road.
• Final line marking.
• Planting in the next planting season.

Keeping safe

While Stage 1 is being upgraded there are 2 things to remember to keep you safe when travelling through our site:

• please avoid walking or cycling through the site
• please drive carefully and always keep to the 60km/h speed limit.

Stage 2 SH16 Brigham Creek to Waimuaku

We're moving at pace with Stage 2 which will be staged in 3 sections as shown in the above map.

Topographical surveys and geotechnical investigations have been completed giving us a clearer understanding of property boundaries, ground conditions, and ground levels. We'd like to thank all property owners who provided access for these investigations and appreciate the community’s patience and understanding throughout this time.

Stage 2 is now entering the property acquisition stage, the diagram below shows the project timeline.

Property acquisition will be staged over the next 3 years, starting with properties in Section 1, followed by Section 2 properties and then Section 3 properties.  All affected property owners will be sent information on next steps by early 2026.

Consent approvals

To move ahead with constructing the project, NZTA must have the necessary approvals in place and have secured all the required land.  All resource consents required have been granted by Auckland Council. NZTA has recommenced the Notice of Requirement process, re-engaging with Auckland Council to progress the application for an alteration to the SH16 designation.

Auckland Council has now contacted all identified affected parties in relation to this application. Please note this is a separate process to the NZTA property acquisition process. For more information see A guide to Notice of Requirement.

More information

If you would like to see more construction photos or get more information on the SH16 Brigham Creek to Waimauku project, please visit nzta.govt.nz/projects/sh16-brigham-creek-and-waimauku or email us sh16safetyimprove@nzta.govt.nz

For Stage 1 construction queries, please contact Nettie Bird, Fulton Hogan Communications and Engagement Manager by emailing nettie.bird@fultonhogan.com or phoning 0800 287 667.