Keeping your trees pruned and clear of lines helps us keep the power on for our community
Property owners and electricity distribution companies are legally responsible for keeping our community's electricity supply safe and secure.
Trees and vegetation growing too close to power lines are hazardous and a major cause of unplanned power outages, especially in storm conditions.
As a tree owner you have a responsibility to look after your trees. The Electricity (Hazards from Trees) Regulations 2003(external link) set out responsibilities for tree owners and electricity lines companies. The Regulations were amended in 2024 and again in 2026, with different changes taking effect between July 2026 and July 2028. (external link)Refer to the MBIE guidelines(external link) for more detailed information to help you understand the June 2026 amendments.
If you do plan to trim your trees we recommend using trained professionals and if you have any questions, call us anytime on 0800 363 9898. We're here to help.
Keeping trees clear of power lines
If you have trees close to power lines you are liable if your trees damage any lines or equipment on the electricity network. The word “trees” includes all types of vegetation including shrubs, hedges and climbing vines.
Hazards from trees that are too close to power lines:
Fire caused by electrical sparking from vegetation coming into contact with lines.
Risk of electrocution for children or anyone climbing trees close to power lines.
Risk of electrocution from vegetation becoming electrically live in severe weather conditions.
Trees and vegetation causing power outages.
Tree roots growing around underground cables, damaging the insulation and causing power supply failure.
Trees near power lines are dangerous
The Electricity (Hazards from Trees) Regulations(external link) have been amended in October 2024 and July 2026. These update includes new minimum safe distances between trees and power lines and a new 'clear to the sky' requirement, the new regulations have a grace period that lasts until 16 October 2026.
Clearance zones
Growth limit zone (GLZ) - Vegetation should remain out of this zone under all conditions.
Cut back zone (+1m from GVZ) – When vegetation is cleared, it is to be removed so that it does not enter this zone. A hazard warning notice may be issued to warn of clearance requirements.
Hazard warning notice zone (+2m from GLZ) – If vegetation enters this zone, a hazard notice may be issued to warn of clearance requirements.
Clear to sky
Note
These are the required distances from the power line.
The distances are from the power line, not the power pole.
These distances are a minimum and apply in all conditions including high wind or snow.
Clear to the sky means vegetation must also be kept clear vertically above power lines in areas where the requirement applies. From 17 October 2026, clear-to-the-sky requirement applies to:
Urban areas – 33 kV and 66 kV only.
Non-urban areas - all voltages.
Clear to the sky does not apply where trees are council protected or where power lines are insulated.
Treefall hazard zone (TFHZ)
This is a new requirement coming into effect 23 July 2028, where lines owners are to assess and then take action to remove or prune trees that pose a moderate or high risk to electricity lines. This applies to trees that are within 24m, either side of the Growth Limit zone that are capable of falling onto powerlines. Tree assessments will be undertaken by a suitably qualified and experienced arborist.
Where a tree is assessed as moderate or high risk, a Treefall Hazard Notice power maybe issued to the tree owner.
There are timeframes associated to the notice.
Where the risk assessment is a moderate treefall hazard the removal timeframe is 45 working days.
Where the risk assessment is a high treefall hazard the removal timeframe is 25 working days.
Wherever possible, we will work with the tree owner to find agreed solutions to reduce the risk to the network. If a Treefall Hazard Notice power has been issued and agreement cannot be reached, then a tree owner will have 10 working days to apply to the Tree Arbitrator if they dispute Orion's assessment.
Trimming trees safely
We recommend you hire trained professionals with the necessary expertise and safety procedures to competently carry out tree trimming.
Contact with a power line can cause:
Risk of electrocuting yourself or others.
Damage to property and other trees.
Damage to the electricity network.
Livestock death or damage.
If you or someone working for you intends to work within 4 metres of power lines, a close approach consent is required from Orion before work commences.
Fines for non-compliance
If a cut or trim notice is given to you and you fail to have the tree trimmed and/or advise us of the time and location of the trim without a reasonable excuse, this is an offence.
This will make you liable for a fine not exceeding $10,000
If the offence continues, you will be liable for a further fine of not more than $500 for every day or part day during which the offence continues
The Law — Electricity (Hazards from Trees) Regulations 2003(external link) sets out the responsibilities of electricity line companies and tree owners. The purpose of the regulations is to protect the safety of the public and help to ensure a secure supply of electricity.
Our trees management programme
Our trees management programme is governed by the Electricity (Hazards from Trees) Regulations 2003(external link) Our programme involves monitoring and pruning or removing trees that threaten to come into contact with overhead power lines. Through this programme we work with tree owners to minimise the risk of their trees touching power lines.
Orion is responsible for the first cut of trees near power lines and the first cut is on a property basis, not owner basis. We have met this obligation by completing a first cut of vegetation on all our lines.
In accordance with the Electricity (Hazards from Trees) Regulations 2003 there is a formal notification process. Where vegetation affects power lines, Orion may enforce that the tree(s) is/are trimmed.
If Orion becomes aware of a tree(s) encroaching the Growth Limit Zone, we will give a Cut or Trim Notice to the tree owner advising them that as soon as possible, or within 45 days the indicated tree(s) must be cut or trimmed to maintain the distances prescribed in the regulations.
It's important to plant carefully near overhead power lines to avoid issues where mature trees and shrubs are in close proximity to overhead powerlines.
Low height planting zone
From 23 July 2027, new rules will apply to planting near power lines on certain non-urban, unforested land.
A Low Height Planting Zone extends 24 metres horizontally either side of a power line. Within this zone, landowners and occupiers must not plant, or allow someone to plant, a tree if they reasonably believe its mature height will be greater than its distance from the power line.
There are exceptions for urban areas, existing forest land, shelter belts and certain conservation land.
Keep clear zone - grass is the only safe species to plant directly below power lines.
Low planting zone - check our tree planting guide below to see the recommended species for 24 metres either side of the keep clear zone.
Tree planting guide
Below is a list of indigenous native trees that will only grow to 4 metres or less, have low flammability, that are suited to the Waitaha Canterbury environment (always seek advice from your local nursery about what is best for your area) and will enhance biodiversity.
