Trees near power lines

Trees and branches near power lines can pose serious risks to the public and can cause power outages, especially during high winds and storms. This page tells you what you need to know and do about your trees.

Trees that grow too close to power lines can be a serious problem. They can cause electric shock, fire, power outages and damage electricity infrastructure.

Keeping vegetation safely clear of power lines helps protect people and helps keep the lights on for you and your community.

The Electricity (Hazards from Trees) Regulations set out the rules that tree owners and lines companies must follow when managing trees near power lines. These regulations are part of New Zealand law.

This page explains the main rules, including what tree owners need to know. If you’re unsure about a tree near a power line, please call us on 03 577 7007 or report a fault here before doing any work.

If there is immediate danger

Call 111 immediately if there is an emergency.

Never touch a power line, and never touch a tree or branch that is touching a power line. If you come across downed lines, never approach or attempt to clear them yourself. Stay at least 10 metres away and call 111.

You should also contact us immediately on 03 577 7007 if:

• a tree or branch has fallen onto a power line

• a tree looks like it could fall onto a power line soon

• a power line is down, damaged, or hanging low

• branches are touching lines

• someone is at risk of coming into contact with the line.

Who is responsible for a tree near a power line?

In most cases, the tree owner is responsible for making sure their tree doesn’t grow too close to power lines. A tree owner is usually the person who owns the land where the tree is growing.

We have responsibilities too. These include:

• carrying out line and vegetation surveys

• providing information about the rules

• issuing hazard warning notices and cut or trim notices where the regulations allow or require

• responding to electricity hazards

• in some cases, meeting the cost of certain work required under the regulations.

How the rules apply

The regulations use several zones around power lines. These zones help determine when trees must be trimmed, when notices can be issued, and what restrictions apply.

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, we may issue a hazard warning notice to alert the tree owner.

If a tree qualifies for its first cut or trim under the regulations, Marlborough Lines 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 us if you’re unsure.

Trees that could fall into a power line

The treefall hazard zone is an area that extends 24 metres from the growth limit zone.

Trees within this zone may be assessed by a lines company. This does not mean every tree in the zone is a hazard. It means the tree may be assessed if there is concern that, because of its condition, size or location, it could fall onto the power line.  A formal treefall hazard notice can only be issued if the tree is assessed as a moderate or high hazard.

Treefall hazard notices will not be issued before 23 July 2028. Before then, Marlborough Lines may use voluntary processes to discuss hazardous trees with tree owners. These voluntary processes are separate from the formal treefall hazard notice power in the regulations.

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 Marlborough Lines.

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 Marlborough District Council.

If you’re planting near power lines, think about how tall the tree is likely to grow over time.

From 23 July 2027, planting restrictions will apply in the low height planting zone outside urban areas, outside existing forest land, and except for shelterbelts and land administered under the Conservation Act 1987.

Check out our helpful links below for:

• recommended trees to plant

• authorised contractors for arborist work.

Vegetation growing above the line - ‘clear to the 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 applies to higher-voltage lines in both urban and non-urban areas, and 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, we 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.

Electricity (Hazards from Trees) Regulations 2003

Safe Separation Distances

The Regulations specifically advise rules for tree owners and electricity network companies with regard to cutting or trimming trees that grow too close to power lines.

Safety clearance distances for spaces surrounding the electrical conductors for spans less than 150m for low voltage (LV), 11kV and 33kV lines.

This includes Growth Limit Zone ‘Clear to sky’ for 33kV lines urban and non-urban and ‘Clear to sky’ for all voltages non-urban.

*ECP34 must also be adhered to, a person or machinery cannot be within 4m of the line unless a Close Approach Permit has been applied for and issued by Marlborough Lines.

Growth Limit Zone safety clearance distances for spaces surrounding the electrical conductors for spans GREATER than 150m for Low Voltage (LV), 11kV and 33kV lines (long line spans)

This includes ‘Clear to sky’ for long line spans 33kV lines urban and non-urban and ‘Clear to sky’ for all voltages non-urban.