O Mahurangi – Penlink

1 October 2024

Earthworks on site near Ara Wēiti Road.

Earthworks season kicks off

A big part of building O Mahurangi - Penlink involves cutting through the hills and filling in the gullies along the new highway corridor.

October sees the start of a busier period for our team as we begin our third earthworks season. Earthworks season typically runs from 1 October through to 30 April, when the weather is warmer and usually drier.

While our 2022/23 season was impacted by wet weather, we made good progress during our 2023/24 season and by the end of April had shifted 461,000 cubic metres.

During the off-season, our team was able to carry out some earthworks as weather and approvals allowed, and neighbours may have noticed an increase in activity through September.

By the end of Season 3, we are aiming to have 1 million cubic metres material of the total 1.2 million cubic metres of earth required to move across the project

As the earthworks progresses the distance between cuts and fills increases in some areas. The team are using some bigger 40 tonne dump trucks (versus 30 tonnes previously) this season to ensure the earthworks is as efficient as possible.

State Highway 1 (left) and East Coast Road (right) bridge abutments being built.

Bridging State Highway 1 and East Coast Road

Our work near the State Highway 1 and East Coast Road bridge sites has become more visible as the bridge abutments are taking form. These bridges are undergoing a construction method that uses ‘mechanically stabilised earth’ (MSE) to create their support structures or abutments instead of traditional piling. MSE uses layers of compacted aggregate material (such as small rocks) reinforced with geosynthetic material to create the abutments.

First, both bridges had deep excavations to remove weaker underlying material. Following this, the excavations were replaced with compacted aggregates and geosynthetic material to create strong foundations. The East Coast Road Bridge also had wick drains installed within the deep excavations to provide underlying water a passage to the surface.

After building the MSE abutments, the East Coast Road bridge will have a 6-month pre-load period. Pre-load is when material is placed on top to help compact the ground below.  Here we are using a combination of ground anchors and heaped aggregate to load each bridge abutment by approximately 3,500 tonnes. These large loads help compact the ground even further to ensure the bridge will be stable and strong for years to come.

Both bridges are single span (no central pier) with prestressed concrete beams.

Ara Wēiti Road temporary diversion roads

To allow construction to continue at pace along Ara Wēiti Road, we will be constructing a temporary diversion road in three stages. Stage 1 (see map below) will be open from mid-October and will remain in place until further notice. Stage 2 is scheduled to open late October with Stage 3 at a later date.

There will also be temporary traffic management in the form of lights or a stop go at times. We send out email work notifications prior to changes so  if you live nearby and would like to be notified, sign up for work notifications here.

Check out the general arrangement plans here to see what the area along Ara Wēiti Road will look like in the future.

Let us know what you think

As we progress with construction, our O Mahurangi stakeholder and engagement team continues to focus on providing timely communication to our neighbours living with and experiencing our activities. We also share regular and targeted updates in a range of ways with the wider community to build awareness of our progress.

Neighbours can connect with our team to stay informed of the project’s progress and know what to expect from upcoming work.  

During construction, we work closely with landowners in the immediate area to minimise any impacts and resolve any issues or concerns.

We also ensure any potential impacts are communicated in advance. Our team are committed to working with you to get the best outcome for the project, our neighbours and the local community, leaving a positive legacy for future generations.

Currently, the O Mahurangi stakeholder and engagement team is conducting a stakeholder satisfaction survey. This survey provides you with an opportunity to provide feedback on your experience with our communication and engagement approach and activities. The insights we gather through the survey will help to refine our communication approach and address any concerns or suggestions you may have.

Take the survey here.

Read more on our communications strategy here.

In addition to providing feedback through the survey, we welcome ongoing feedback on our communication strategy at any time. You can reach us via our project email at omahurangi@nzta.govt.nz or by calling 0800 7365 465.

Save the date: November drop-in sessions

Come along to one of our community drop-in sessions in November to meet the team and learn more about the project. We’ll have information on progress and upcoming works in the area.

• Saturday, 2 November 2024, 10:00 am - 1:00 pm at Stillwater Boat Club (70 Duck Creek Road, Stillwater 0993)
• Saturday, 9 November 2024, 10:00 am - 1:00 pm at Hibiscus Coast RSA (43a Vipond Road, Stanmore Bay 0932)

If you can’t make one of the sessions above, we welcome feedback at any time. You can reach us via our project email at omahurangi@nzta.govt.nz or by calling 0800 7365 465.

The landscaping team at Long Bay Regional Park with newly planted native trees behind them.

Planting season success

Our landscaping team recently completed this year's planting season, working through all sorts of weather conditions. The project plants vegetation both within and outside the project’s boundary to mitigate the effects of removing native trees and vegetation for construction.

In total, the team planted 150,327 native trees at Archer's Block and Long Bay Regional Park, which will support the natural environment for years to come.

Wēiti River Bridge timelapse

Watch a timelapse of the Wēiti River Bridge's progress to date by clicking here or on the image above. Be sure to watch it in high-definition by increasing the video quality to 1080p under the ‘settings’ button in the bottom right corner.