When to trim your trees

If a tree, hedge, or shelter belt is not maintained as per the requirements and/or regulations, it can cause serious issues if it comes into contact with the electricity network.

Please don’t wait to be reminded that your trees need to be cut.

It is your responsibility to make sure your trees and vegetation are clear of network assets. 

Be proactive: Regularly inspect your trees and be aware that if your trees cause any problems on our network, you can be charged for all costs of repair.

If you are unsure, give us a call on 0800 30 90 80 and we can help. 

Some work requires people or machinery to get closer than 4 metres from power lines. This requires a close approach consent from MainPower. Click here to find out more about close approach consents.

We’re here to help. Get in touch if you need help. Or, check out our FAQs.

When to trim your trees

Please don’t wait to be reminded that your trees need to be cut.

It is a legal requirement (not set by MainPower) that you act in accordance with the Electricity (Hazards from Trees) Regulations 2003.

Be proactive. Regularly inspect your trees. If they are in any of the zones detailed below, they must be trimmed safely. 

Call us on 0800 30 90 80 for a free inspection and a quote from our utility arborists.

Tree growth zones

There are three zones for trees growing close to power lines and other electrical equipment: the Notice zone, the Cut-back zone, and the Growth limit zone.

“Clear to the sky” is a new requirement for all lines 22 kV or greater, plus certain high-risk lines at 11 kV. It was announced in October 2024, but it will not be enforced until 16 October 2026.

If your tree is growing within the Notice zone or the Cut-back zone, it must be trimmed soon because it is growing too close to power lines and equipment. If your tree continues to grow into the Growth limit zone you will receive a legal notice from us requiring the tree to be trimmed (by a qualified contractor) within a specified time frame.

Tree growth zones notes

Fall hazard zone

This zone is where trees might present a hazard if they fall and damage power lines. The closest a tree can be located is calculated as the height of a tree plus 4 metres.

Don’t forget, before you plant any trees or hedges near power lines, plant those that have a slow growth rate, or dwarf species, otherwise you will be trimming on a regular basis, which is time consuming and costly.

Cutting trees near live lines

Due to the risk of danger, cutting trees near live power lines is a very specialised job. MainPower has its own team of experienced and qualified utility arborists. Click here to find out more about MainPower’s tree services and book a free tree trimming inspection.

Some work requires people or machinery to get closer than 4 metres from power lines. This requires a close approach consent from MainPower. Click here to find out more about close approach consents.

We’re here to help

If you need some assistance or advice, please get in touch with our team.

Outage notifications

WIND WARNING AND OUTAGES

Due to high winds today, there are a number of power outages on the MainPower network. Our teams are working to restore power as safely and quickly as possible. A number of customers will remain without power overnight until it is safe for our teams to carry out repairs. If you are affected by outages, please enact your No Power Plan.

There is a significant weather event due to impact the network on Thursday 23 October. Customers in the North Canterbury area should prepare for power outages that may last some days.

Medically dependent customers should ensure their power retailer has their most current information, have spoken to their medical professional and are prepared to relocate if needed.

For the most recent updates on outrages, please check our outage map.

We appreciate your understanding and patience during this time.

Treat all power lines as live. Power can be restored at any time. To report an outage, call 0800 30 90 80.

Is your outage not listed?

Troubleshoot your outage
Treat all lines as live during the outage period; power may be restored at any time. If you require further information, please call MainPower’s 24-hour faults line. To report an emergency, call 111.

Outage notifications

WIND WARNING AND OUTAGES

Due to high winds today, there are a number of power outages on the MainPower network. Our teams are working to restore power as safely and quickly as possible. A number of customers will remain without power overnight until it is safe for our teams to carry out repairs. If you are affected by outages, please enact your No Power Plan.

There is a significant weather event due to impact the network on Thursday 23 October. Customers in the North Canterbury area should prepare for power outages that may last some days.

Medically dependent customers should ensure their power retailer has their most current information, have spoken to their medical professional and are prepared to relocate if needed.

For the most recent updates on outrages, please check our outage map.

We appreciate your understanding and patience during this time.

Treat all power lines as live. Power can be restored at any time. To report an outage, call 0800 30 90 80.

Is your outage not listed?

Troubleshoot your outage
Treat all lines as live during the outage period; power may be restored at any time. If you require further information, please call MainPower’s 24-hour faults line. To report an emergency, call 111.

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