SH1 Papakura to Drury

Construction update

4 April 2025

Construction update | He pānui

Kia ora

Daylight saving time may be ending this weekend but the Papakura to Drury project's momentum continues to accelerate.

The project team made great progress over the last month, which was notable due to the establishment of several new work sites. A critical priority when setting up new sites, and before any earthworks get underway, is the implementation of robust erosion and sediment control (ESC) measures to protect the environment. See the next story for more details.

Currently, we are working across multiple fronts along the length of the project. On Bremner Road, construction of the temporary steel truss bridge is ongoing and underground service investigations continue, including on Creek Steet. At Slippery Creek / Otuuwairoa Stream, earthworks have started ahead of construction beginning on new higher motorway bridges across the stream and raising the motorway higher.

At Flanagan Road, our team is halfway through building an impressive retaining wall that has been under construction for the past several months. Read more on this below.

On the Southern Motorway itself, shoulder widening works have been progressing at pace in preparation for shifting northbound traffic lanes over to the west this Sunday night (weather permitting). Please drive safely as you navigate and become accustomed to the new layout of motorway lanes in the coming weeks.

Combined with the mid-February shift of southbound traffic lanes over to the east, the two traffic shifts put together will enable the team to begin working within the central median of the motorway in the coming month. 

A combination of bunds and silt fences used for erosion and sediment control at a Victoria Street site.

Protecting the environment | Tiakitanga o te taiao

Erosion and sediment controls (ESC) are a critical environmental management practice used during construction activities to ensure the land (whenua) and waterways (awa) are protected. If proper care is not taken, soils and material may be lost from the land and end up in waterways – causing contamination, silting and negative impacts on wildlife and their habitats.

ESC measures are typically installed when a worksite is first set up and, in many cases, these remain in place until construction works are completed. Later, long-term ESC measures are installed immediately before project completion, to ensure sustained environmental protection.

A range of different ESC measures can be used, with each tailored to the specific conditions of each site and the project’s requirements. ESC measures include silt fences; sediment traps; geotextiles; runoff diversion channels and bunds (earth embankments); and planting selected types of vegetation. Within this project, silt fences are the most frequently used ESC measure, providing an effective barrier against the spread and loss of sediment from the site. Other ESC measures, such as bunds and sediment traps, are installed at individual sites as required by individual site conditions and the potential environmental risks.

After the completion of construction works in a particular area, fibre mats are laid to stabilise the soil surface, which supports the establishment of long-term sediment control through planting vegetation. This process ensures ongoing environmental protection even after the project team departs the site.

The fibre mats used exclusively on the Papakura to Drury project are 100% biodegradable coconut husk fibre (coir) mats, which contain a fully biodegradable jute mesh – meaning no plastic components and minimising the project's environmental impact. These coir mats promote natural vegetation growth, further enhancing long-term erosion controls and ecological restoration.

Backfilling in progress at the retaining wall near Flanagan Road.

Retaining wall | Taiapa pupuri whenua

A significant part of the Papakura to Drury project involves the construction of several large retaining walls. One of these is located near Flanagan Road, which we began construction on last November.

This retaining wall (shown above) is being built because both Flanagan Road and the Waikato water pipeline must be realigned eastward closer to Hingaia Stream – necessary as the motorway and Drury Interchange will be shifting eastwards too.

When completed around May this year, this retaining wall will have used about 10,000 cubic metres of backfill material, 1,150 tonnes of concrete and 118 steel beams. These steel beams vary from 12.5 metres to 14 metres in length.

Other large retaining walls for the project yet to begin are walls alongside State Highway 1, State Highway 22, Bremner Road, and the North Island Main Trunk railway line. We will tell you more about these other walls when construction begins for each.

Latest photos from site | Ngā pikitia

We are removing vegetation, investigating underground services, carrying out earthworks, paving and piling across the project extent – all activities require environmental controls.

Looking ahead | E haere ake nei

During the coming months, our project works include:

• Completing a large retaining wall at Flanagan Road
• Continuing with underground service investigations around Drury Interchange including on the motorway, Great South Road, SH22, Bremner Road, Victoria Street and Mercer Street
• Working to realign the Victoria Street intersection with SH22 before installing traffic lights
• Building a temporary steel truss bridge over Ngaakooroa Stream for Bremner Road traffic
• Demolishing and rebuilding the existing Bremner Road bridge over the Ngaakooroa Stream
• Continuing earthworks either side of Slippery Creek / Otuuwairoa Stream in preparation for bridge building works
• Starting construction works in the central median of the motorway between the BP motorway service centre and Drury Interchange.

Contact us | Whakapā mai

For further information regarding the project, please contact our team:

P: 0800 796 796
E: p2b@nzta.govt.nz
W: www.nzta.govt.nz/p2b