Bookmark this page to:Add to Twitter Add to Multiply Add to Yahoo Bookmarks Add to Yahoo MyWeb Add to Facebook Add to LinkedIn Add to Terchnorati Add to Digg Add to Google Bookmarks Add to Reddit Add to StumbleUpon Add to Delicious

Trees and Powerlines

Tree owners are legally required to ensure their tree(s) don’t grow too close to powerlines. The Electricity (Hazards from Trees) Regulations 2003 were introduced by the government because trees need to be kept at a safe distance from electricity lines for public safety and to protect electricity supply. 

When trees grow too close to powerlines, they have the potential to cause power fluctuations and appliance damage, power failure, fire, electric shock or electrocution.

We have an ongoing vegetation control programme in place to maintain a safe clearance between trees and powerlines.

If you know of trees which are causing interference or have the potential to cause interference with an electricity line please give us a call on 03 577 7007.

Electricity (Hazards from Trees) Regulations 2003

The Electricity (Hazards from Trees) Regulations 2003:
  • Define safe separation distances between trees and powerlines.
  • Specify who is responsible for ensuring clearances are maintained.
  • Place potential liability on the tree owner if any damage or accident occurs when trees touch powerlines,
Further information about the Electricity (Hazards from Trees) Regulations 2003, including the responsibilities of tree owners and network companies, can be found here.

We’re working to improve the Electricity (Hazards from Trees) Regulations 2003
Over the years Marlborough Lines has experienced difficulty trying to interpret and apply the Regulations, and in some instances disputes with tree owners have occurred. For this reason, we applied to the High Court in 2011 for various declarations regarding the Regulations in relation to a dispute with a tree owner.

The High Court decision, Marlborough Lines v Cassels HC BLEN CIV-2010-406-147, was issued in early 2012, and has significant implications for electricity network companies.  The judgment marked the first time the Regulations have received judicial consideration, despite many electricity companies having had difficulties applying the Regulations. 

Marlborough Lines and its solicitors have drafted new Regulations which would, in their view, be more workable and fair to both electricity companies and tree owners.  The draft regulations are currently being circulated within the industry for discussion.

Vegetation control programme

We operate an ongoing and extensive vegetation control programme to reduce the risk of:
  • Accidental electric shock or electrocution.
  • Fires caused by electricity.
  • Power fluctuations or interruptions caused by branches touching, or being blown into, powerlines.
For all vegetation control work we try to obtain a solution with the tree owner that’ll eliminate the problem for a reasonable period because we have 3,300km of line which needs to be kept free of trees if we are to provide a reliable supply. In all cases we work with the tree owner to reach a mutually acceptable solution.

How you can help

Plant only recommended trees under or near our power lines. Recommended trees grow less than four metres tall and don't tend to shed branches or fronds. Contact us if you know of trees that are causing interference or have the potential to cause interference with a power line - 03 577 7007.

Electricity (Hazards from Trees) Regulations 2003

The Electricity (Hazards from Trees) Regulations 2003 set down rules for tree owners and electricity network companies with regard to cutting or trimming trees that grow too close to electricity network lines. For spans of 150m or less, the legislation requires clearances of:

Line Voltage Notice Zone Growth Limit Zone
33,000V (33kV)  3.5 metres  2.5 metres
11,000V (11kV)   2.6 metres 1.6 metres
400V / 230V   1.5 metres 0.5 metres

Spans over 150m are subject to multi-part horizontal and vertical clearances. Please contact Marlborough Lines for additional information.

Once vegetation encroaches within these distances, Marlborough Lines will issue the tree owner with a ‘Cut or Trim Notice’. For this reason, greater cut distances than the ‘Notice Zone’ are required to achieve a reasonable return time. 

Tree clearance around lines

Marlborough Lines’ responsibilities

All electricity network companies, including Marlborough Lines, are required by the Regulations to ensure that trees do not grow too close to our (network) lines or electrical equipment. We are responsible for:
  • Inspecting our networks to identify trees inside the Growth Limit Zone. The Growth Limit Zone specifies the distance around powerlines and electrical equipment which must be kept clear of trees, shrubs and vegetation. The Growth Limit Zone varies for different voltages and span lengths.
  • Providing the first cut or trim free of charge for trees inside the Notice Zone, unless the tree is covered by a previous arrangement with us, or is part of a horticultural shelterbelt. The Notice Zone is the space extending not more than one metre beyond the Growth Limit zone. This zone provides for growing time so that trees can be cut before they grow into the Growth Limit Zone.
  • Notifying tree owners with a cut or trim notice when a tree is too close to powerlines.
  • Ensuring the tree owner complies with the Cut or Trim Notice and the Regulations.

Tree owner’s responsibilities

Network powerlines

After the first cut or trim, it is the tree owner’s responsibility to keep the tree clear of the Growth Limit Zone around network powerlines.

Marlborough Lines will notify residents of a property with a Cut or Trim Notice when a tree needs to be cut or trimmed. The tree owner must comply with that notice using an approved arborist, within the time stated.

Important: Do not trim trees near network lines yourself as this is very dangerous. The Regulations require the work be undertaken only by professional arborists approved by the electricity network company.

In Marlborough tree trimming can be undertaken by Marlborough Lines Contracting or other approved arborists. The Department of Labour’s Safety and Health Service has issued an improved Code of Practise for tree work and a Code on Tree Maintenance around powerlines.

Service lines

The property owner is responsible for the maintenance and repair of electrical lines and equipment, known as service lines, on their property. This means property owners are responsible for the costs of trimming trees near their service lines.

You can hire a qualified arborist, or you can do-it-yourself – but remember that unless you are using someone qualified to work around live lines, always have your power supply temporarily disconnected before working near service lines.

To arrange a temporary disconnection phone us on 03 577 7007.


Electricity networks and tree owners must comply with the requirements of the regulations and are both liable for financial penalties if they fail to comply.

A notice to cut or trim a tree cannot be ignored.

Tree owners must comply with the notice in the time stated and advise of the time and location of the cutting or trimming of the tree, or they could be fined up to $10,000 plus other costs, and could also be liable for costs if powerlines or equipment are damaged by a tree. If the offence continues, a further fine of up to $500 per day could be imposed for every day, or part of a day, that the offence continues.

Dispensation and disputes

Tree owners are entitled to request dispensation from a notice to cut or trim a tree. However under the Regulations, trees must be kept clear of the Growth Limit Zone – dispensation cannot be granted for a tree which is inside this area.

When a tree owner requests dispensation, Marlborough Lines will check whether or not the tree is inside the Growth Limit Zone and consider the other safety issues required by the Regulations. The Minister of Economic Development is responsible for appointing arbitrators to hear and determine disputes between tree owners and network owners. The Regulations allow a tree owner to contact an arbitrator in the case of a dispute if:
  1. The network owner has refused to grant a dispensation which the tree owner believes should have been granted.
  2. A dispensation has been granted but the tree owner does not agree with its terms.
For other matters there is the option of contacting the Electricity and Gas Complaints Commissioner Scheme, which is a free of charge and independent service.

If you have any concerns or queries about your tree trimming responsibilities please don’t hesitate to give us a call. Through acting together we can eliminate danger and maximise the security of your electricity supply.


This page is best viewed in an up-to-date web browser with stylesheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so. The latest version of Firefox, Safari, Google Chrome or Internet Explorer will work best if you're after a new browser.