Last update: 11 October 2023

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Please also refer to information on posters and the non-technical summary of the RMA applications:

Project update and status

What is the current status of the Ō2NL new highway project?

Waka Kotahi, Muaūpoko Tribal Authority and local hapū of Ngāti Raukawa ki te Tonga are working together to create a positive legacy for the region while we build a new, safer and more reliable State Highway 1 from Ōtaki to north of Levin.

In April/May 2022, we shared the preliminary concept designs for the new highway and shared user path with the public and asked for feedback.

In November 2022, we lodged the Notice of Requirement and Resource Management Act applications with Greater Wellington and Horizons Regional Councils, and Kāpiti Coast and Horowhenua District Councils.  The applications have been referred to the Environment Court.

When will the new highway be built?

We currently estimate construction to begin in 2025 and take approximately five years to complete.

Preliminary concept designs

Will Tararua Road connect directly with the existing SH1 when the new highway is open?

As part of the Ō2NL project we are proposing a significant upgrade of this intersection and level crossing. The proposed design connects Tararua Road straight across the railway to form a new T intersection with the existing SH1. With this design, the current level crossing would be relocated southwards and would entail coordinated signalisation of the intersection with the level crossing, new right and left turn bays on Tararua Road and on the existing SH1 and separate walking and cycling facilities across the railway line. We are working closely with KiwiRail and Horowhenua District Council on this intersection.

Why build roundabouts on the new highway?

There are currently two roundabouts planned on the new highway route, and both are at the northern end of the road. A large roundabout will provide connections from the new highway to SH57 (and Palmerston North beyond) in the north, and Arapaepae Road (towards Levin) in the south.

At the northern end of urban Levin, a large roundabout will signal the end of the new highway and act as a gateway to Levin. It will connect the new highway to SH1 to the north, the existing SH1 to the south and Heatherlea East Road.

Roundabouts are being considered in these locations, rather than a half or full diamond interchange, for numerous reasons. In both locations, these roundabouts connect to the existing two-lane state highways. They have been designed to prepare traffic for a changing road environment. With Te Aranui o Te Rangihaeata (Transmission Gully), Peka Peka to Ōtaki and Ōtaki to north of Levin highways complete, drivers will travel from Wellington to Levin on four-lane, median separated highways and these roundabouts will signal a shift from this new highway environment onto a much narrower two-lane road on SH57 or SH1 beyond.

Currently, the average daily traffic numbers north of Levin are 11,631 on SH1 and 9,472 on SH57. Traffic modelling projections indicate roundabouts are suitable in these locations. The Tararua Road interchange manages transitions on and off the new highway before this traffic separates - there are currently about 20,000 vehicles a day on SH1 at Ohau.

Roundabouts also have a significantly smaller footprint than interchanges.

Noise and vibrations

When the road opens, how loud will the new highway be?

Road traffic noises will meet or exceed the requirements of the New Zealand Standard. This will be achieved by using a noise reducing surface (known as Open Graded Porous Asphalt – OGPA) and complementing that with noise barriers and further layers of OGPA in some locations.

The road surface needs to settle for 12 months before the OGPA can be installed to ensure its effectiveness and longer-term performance. During this period, road traffic noise levels will be slightly higher than predicted.

Will trees reduce noise?

Trees and planting will not reduce the measurable noise levels (unless for a significant depth), however they are effective at reducing the perception of traffic noise. Extensive planting will occur as part of the project.

Will I notice vibration from construction activities/machinery or from trucks and heavy vehicles when the road opens?

The distances to houses are such that no vibration effects are predicted.

Landscape / visual

Will habitats for birds and fish be left when the new highway opens?

Ecological restoration will include:

  • Enhancing existing forest stands as remnants and ecological steppingstones
  • Using culverts and bridges that maintain naturalised stream flow, aquatic habitat and fish passage upstream and downstream
  • Delivering a net improvement in water quality in rivers and streams, and water flowing into lakes

How long will it take for planting to soften visual effects?

While some planting will be able to be carried out during construction, most planting is located on earth-worked areas and will need to be done after construction is complete. Planting can achieve good coverage in five years. Tall screen planting will grow up to 5-8m in about 10 years.


What will be the effects of construction on birds/trees/fish in streams?

The selection of the route has minimised effects on native forest vegetation and habitats by avoidance where practical, but some native vegetation, wetlands and streams are crossed by the project.

Before construction starts, native fauna areas will be cleared of geckos, snails and leptinella and relocated to an area of equivalent or better habitat.

Construction will be timed to avoid removal of woody vegetation during birds nesting season. Streams and river crossings will involve diverting waterways and fish passage will be maintained during construction. Fish, eels and macroinvertebrate will be relocated ahead of construction.

My property already gets flooded will Ō2NL make this worse?

The design of the Ō2NL project ensures a hydraulically neutral outcome meaning stormwater will be captured in the proposed ponds and retained and released after a flood event at the same rate as would have been experienced prior to the project being built.

Culverts and bridges are designed to maintain existing flood flow conditions; so there are no flooding effects downstream of the alignment, and instead in bigger flood events the project will slow water flooding downstream as the culverts will throttle flows through/ under the project resulting in a small /marginal downstream flooding benefits to downstream properties.

Will stormwater runoff into streams, rivers and groundwater?

Permanent stormwater treatment devices will be installed to catch runoff from the new road surface and treat it to a high level before it is discharged to ground or to natural water courses (mimicking existing flows). Around 80% of all particles and contaminants in runoff (and which gather on road surfaces) will be removed using naturalised swales, stormwater pond systems/ constructed wetlands and engineering treatments prior to discharge.

The current state highway network has no specific treatment for runoff and so shifting traffic onto the proposed new highway will result in a small overall improvement in water quality in the region.

Managing construction effects

How is construction dust managed and what happens if dust comes onto my property?

This will be managed using usual dust mitigation measures including:

  • water spraying on site and on haul roads to manage dust from earthworks
  • wheel wash and cover eg, over trucks on vehicles travelling on public roads
  • progressively stabilising exposed earthwork areas through rolling, mulch, planting, or other methods
  • careful management of equipment and working areas, and of construction traffic activity (on and off site)
  • keeping in touch with adjacent property owners to identify potential issues at an early stage and ensure ‘no surprises’.

A Management Plan will be prepared that includes how these measures will be implemented and delivered. This Management Plan will be prepared later by the constructors and will be checked by the Regional Councils who will require constructor compliance. Despite these measures, there is a chance that some dust may travel beyond the boundary of the Ō2NL construction area in particular wind and weather conditions. Should this occur we will consider if further action is needed, such as:

  • assessing water supply for rain roof water collection systems and effects on water filters
  • laundry and or house cleaning
  • assessing and watering /washing down plants or solar panels as needed.

The Management Plan will also include a complaints procedure so any issues arising during construction can be discussed and resolved. 

How is noise managed during construction?

Construction activities will be required to comply with NZS6803:1999 construction noise standards. These standards set levels to be met at residential neighbours to the project work on weekdays, Saturdays and Sunday and Public Holidays; construction noise will normally be limited to day time hours and may be seasonal.

Where the proposed route is close to houses, people may hear noise from construction. Steps will be taken to limit noise effects on homes and properties, including:

  • careful management of construction methods, equipment and working areas, and construction traffic activity, in particular close to sensitive receptors such as houses
  • temporary noise barriers and muffling of otherwise noisy machines
  • managing hours of work including daily start up and close down procedures
  • keeping in touch with nearby property owners to identify potential issues at an early stage and ensure ‘no surprises’.

A Management Plan will be prepared to establish processes for managing effects. This will require constructor compliance and set out the management methods, as well as monitoring, review and corrective action processes.  Details will be communicated clearly and discussed with our neighbours to understand how noise can be managed in the context of needing to construct the project. There will be clear complaints and corrective action procedures.

How are community traffic connections maintained during construction?

The construction of the proposed highway has the potential to disrupt access to properties and connections to communities. We will manage construction traffic on local roads to ensure people can still travel to and from their homes including to local schools, recreational areas, community facilities and shops. We will aim to reduce or avoid delays to your journeys but acknowledge that this will not be possible at all times.

We will aim to reduce traffic on the local road network by establishing haul roads and access tracks along the project area to minimise the interaction of construction machinery with the local road network.

How will I be able to access my property during construction?

While the construction of the proposed highway has the potential to disrupt access to properties and connections to communities, access to all properties will be available at all times. In some instances temporary access arrangements will need to be provided and these will be discussed with affected properties. In some instances new access points into property will need to be developed and these details will be discussed with the property owner to make sure that accesses are similar to current.

We will manage construction traffic on local roads to ensure people can still travel to and from their homes including to local schools, recreational areas, community facilities and shops. We will aim to reduce or avoid delays to your journeys but acknowledge that this will not be possible at all times, as safe access is likely to need slowing traffic and in some instances diversions.