As a property owner you are responsible for keeping the trees on your land clear of overhead power lines. The Electricity (Hazards from Trees) Regulations 2003 set out that obligation and the minimum safe distances that go with it.
What the regulations are for
The regulations exist to do two things:
- One, keep people safe. A tree touching a live line can kill the person standing under it, and in dry weather it is a serious fire risk.
- Two, keep the power on. Vegetation growing into lines is the single largest cause of unplanned outages on our network.
To do that, the regulations prescribe minimum safe distances between trees and conductors, set out what tree owners and lines companies each have to do, state the penalties for failing to comply, and provide an arbitration process for settling disputes between a tree owner and The Lines Company.
Trees that could fall on the lines
A tree can be well clear of the conductors and still be a problem. If it is tall enough to reach the line when it falls, it sits in the fall hazard zone — the height of the tree plus four metres in any direction. Shelter belts, old macrocarpa, poplars and gums along fence lines are the usual culprits.
Fall zone trees are not yet covered by the regulations, so we can’t require you to deal with them. But if you own a tree in the fall zone and you have any doubt about its health, its lean or the ground it stands in, tell us and we’ll talk through the options with you. It is far cheaper to take a tree down on a calm day than to repair a line and a shed after it comes through them.
This is changing. Amendments announced by the Minister for Energy in April 2025 will let lines companies assess the risk of a tree falling onto a line and issue a Treefall Hazard Notice for moderate and high-risk trees. We will update this page as soon as those changes take effect.
Trees growing too close to a power line
The regulations include three zones around a power line. These help explain when vegetation is getting too close and when it needs to be cut back.
- Growth limit zone: The space immediately around a power line that must be kept clear of vegetation. The size and shape of the growth limit zone depends on the voltage of the line and, in some cases, the span length of the line.
- Cut-back zone: This extends 1 metre out from the growth limit zone. If a tree is growing into the growth limit zone, it needs to be trimmed back far enough to reach the cut-back zone unless a dispensation applies.
- Hazard warning notice zone: This extends 2 metres out from the growth limit zone. If vegetation enters this zone, The Lines Company may issue a hazard warning notice to alert the tree owner.
If a tree qualifies for its first cut or trim under the regulations, The Lines Company will pay for that work. After that, keeping the tree clear of the power line — and paying for any trimming that’s needed — is the tree owner’s responsibility.
Different rules can apply in some circumstances, so check with The Lines Company if you’re unsure.
Planting a new tree near a power line
On 23 July 2027, a low height planting rule comes into effect. This means you must not plant a tree if you reasonably expect it could grow taller than its distance from the power line.
The low height planting zone extends 24 metres horizontally from the power line.
If you plant a tree in breach of this rule:
- you may be liable for damages
- you may be responsible for the cost if the tree later needs to be cut, trimmed or removed
- you cannot use a ‘no-interest’ tree notice to transfer responsibility for managing the tree to the lines company.
The planting restriction does not apply to trees that grow naturally. However, if a self-sown tree within the low height planting zone later needs to be cut, trimmed or removed, the tree owner may be responsible for the cost.
There are some exceptions. The low height planting zone does not apply:
- on existing forest land
- in urban areas
- to shelterbelts
- on land administered under the Conservation Act 1987.
Not sure whether your property is in an urban area? Check your district plan or contact your local council.
Vegetation above the line – ‘clear to sky’
For some power lines, the growth limit zone extends vertically above the line as well as around it. This is known as ‘clear to the sky’ and means vegetation must also be kept clear above the line.
Clear to the sky already applies to higher-voltage lines in both urban and non-urban areas. From 17 October 2026, it will also apply to lines at 11 kV or below outside urban areas.
What happens if a tree grows too close to a line?
If a tree is too close to a power line, The Lines Company may contact the tree owner. Depending on the situation, this may include:
- providing information or advice
- issuing a hazard warning notice
- requiring the tree to be cut back
- taking further action allowed under the regulations if the issue is not addressed.
The exact process depends on the type of risk and which rules apply. If you receive a notice, it’s important to read it carefully and act within the required timeframe.
