South Waikato National Grid Connection


 Map of the South Waikato National Grid connection route

Powerco is investing over $43 million to improve reliability and increase capacity of power supply for the South Waikato towns of Putāruru and Tirau, and the Hinuera area. We’re building a new connection to the National Grid with a 110kV circuit from Transpower’s Arapuni substation to supply a new transformer at the existing Powerco Putāruru substation.

The area is currently supplied by a single line between Transpower’s Karāpiro and Hinuera substations. When the line experiences an outage or is out of service for maintenance there is complete loss of power to about 11,500 addresses. Once the new Powerco circuit and transformer are commissioned, this additional national grid connection will help ensure security of power supply for the region.

South Waikato FAQs

We can never 100% guarantee supply, however the circuit will help ensure security of supply for the region, providing extra capacity to cope with growing demand, and providing an alternative line of supply when the single Transpower line the area currently relies on is out.

At this stage we plan to start construction by the end of 2021 and be complete by mid-2023.

It will be an 110kV line.

We’re building the circuit to connect Transpower’s Arapuni Substation at the end of Powerhouse Road to our Putāruru Substation on Arapuni Road.

In 2019, early in our planning process, we engaged with local iwi and the South Waikato District Council around the project.

Following that engagement we initially proposed building the circuit within road reserve per the map below.

(Road reserve is set aside for the construction of essential service infrastructure like gas, electricity, communications, water and wastewater – which is why services like ours are usually visible along roadsides).

We engaged again with Iwi, the local community (through a public information session) and the South Waikato District Council, Mayor and Councillors (through a presentation at chambers) in October 2020 to share the proposed line route.

Proposed circuit route map

We heard feedback from the public and Council, in particular opposing the proposal to take the line through Old Taupo and Pearsons Roads.

In response to that feedback we reviewed the route, which included moving part of the route to go through private land parallel to Arapuni Road (see the map below).

We then engaged with landowners to secure easements to build the circuit through their land. We successfully completed those negotiations in May 2021 and subsequently confirmed the route shown in the map below.

Map of circuit route

We returned to the community in June 2021 to share the confirmed route and our detailed map. We’re now reviewing further feedback from the people who live, work and enjoy the amenities along the route as we work towards finalising the design. In particular we're currently assessing alternative overhead line routes for part of the connection - to see if the visual impact on the Pokaiwhenua Stream and the Duxfield Reserve areas can be minimised (see the map below).

We aim to have the assessment completed early 2022 and we've engaged independent, external experts to provide input so we can be confident the options are considered thoroughly.

To keep the overall project on track, we're starting construction for the sections of the route that are confirmed, while we work to determine whether the line route can be adjusted.

Map of the South Waikato National Grid connection route

Not necessarily. We place stakes in the ground as part of our detailed design work. This process helps to ensure that we place the poles in the most suitable locations. It considers factors such as road safety and vegetation. We staked a number of pole placement options, so if you see a stake it doesn't necessarily mean a pole will be placed there.

Yes. We follow international guidelines for exposure to electric and magnetic fields (EMFs). At its peak (standing right underneath lines for instance), the EMF would be 9.9 microteslas, well beneath guidelines which recommend exposure of no more than 200 microteslas.

The lowest line will be 6.5m above the ground.

Vegetation will need to be kept clear of the overhead sections of the circuit. We'll be assessing where vegetation will need to be removed as part of our detailed design work. We will cover all costs associated with removing trees and vegetation, and will be in touch with individual landowners if there are any trees that need to be removed from private property.

The poles will be 18-20 metres high, with spans of 50-200 metres between each pole.

Here are some artist’s impressions of what the poles will look like.

Artist's impression of overhead line

Artist's impression of overhead line

Artist's impression of overhead line


Detailed designs will be ready by the end of 2021.

We are using a mix of underground cable and overhead lines due to considerations including cost and terrain.

All high voltage lines can emit noise - usually a hissing during wet weather and a low hum may be audible during fine weather. The line is being designed to meet the relevant AS/NZ7000 2016 standard which states that audible noise levels must comply with Environmental Protection Authority, government authority and local council regulations for noise.

We don't anticipate causing any issues to phone, radio or communications dish devices. We are designing the overhead line to national guidelines which consider the impact to any communications.

As part of identifying the route for the connection we engaged CFG Heritage Consultants to assess whether there were any areas of archaeological or historical significance in proximity to the route. Their report identified areas of significance however none were found near the line route. The report has been shared with Maungakaretū Marae and Raukawa. Maungakaretū iwi representatives identified that there are burial caves and an historic battle site in the area, however these are on private land some distance from where the connection is being built. 
Yes, as part of the design process we’ve incorporated feedback from traffic safety experts. Pole placement considers things like bends in the road, and a driver’s view of the road when coming out of a driveway or a side road.
In the unlikely event that a line comes down, the system will automatically detect and operate substation equipment to cut electricity supply to that part of the line. This will occur within 0.5 seconds of the fault being detected.

COVID-19 protocols are in place onsite to protect crews and customers. That means our contractors (Northpower) will be:

  • Working in bubbles.
  • Keeping a 1 metre distance from people within work bubbles where practicable.
  • Keeping a 2 metre distance from the public and other work bubbles.
  • Providing evidence of vaccination status where required.
  • Scanning into work sites using the Government COVID tracer app.
  • Wearing a mask when social distancing is not practicable.

Latest project update

Friday, July 02, 2021
We're incorporating feedback from the community, council and Iwi to finalise the design of our new circuit.


Construct new substation buildings.



Confirm route for the circuit.

Finalise the detailed design for the circuit.



Begin construction of circuit.



Commission new circuit.

Supporting documents

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