Tree Hazards
The recent introduction of the Electricity (Hazards from Trees) Regulations 2003 defines the respective rights and obligations of tree owners and line owners, with regard to power lines near trees. These regulations seek to reduce outages and fluctuations in electricity supply and other hazards, including the risks of fire and human injury caused by the proximity of trees to electricity lines.
Trees and power lines don't mix. Any tree near overhead lines that grows higher than 14m will become a nuisance or hazard, possibly causing a loss of power or worse, a dangerous situation. At Eastland Network Limited (ENL), if we become aware of such a hazard, we will issue the owner with a hazard warning notice notifying them the tree encroaches a power line zone.
A tree that is left untrimmed, brushing against the power lines can cause supply interruptions and at worst, a tree branch crossing a power line can cause a tree to become live. This can also be the cause of prolonged periods of power outages, as finding the cause of the interruption, means our repair crews may have to check every kilometer of line on the affected circuit, leading to a delay of several hours before power is restored.
Planting Trees
When planting trees, place them where they are unlikely to grow into the lines - keeping a minimum clearance of 1.5 metres below the power lines and at least 3 metres to the side. The correct placement and choice of tree type will save future problems. Many smaller trees and shrubs are suitable for planting near overhead lines and still provide good shelter. Some suitable New Zealand natives include:
- Akeake
- Kawakawa (Pepper Tree)
- Manuka (Tea Tree)
- Mapau (also known as Red Matipo)
- New Zealand flax
Pruning Trees
If you have trees near power lines, we strongly recommend that you hire a professional tree pruner, with the expertise to cut around live power lines. There are considerable safety issues around trimming and felling trees near power lines. It is extremely hazardous and requires appropriate skills, specialised safety equipment and procedures. The Department of Labour has issued an extensive Occupational Safety and Health (OSH) Approved Code of Practice for tree work, including tree maintenance around power lines.
The code specifies only an approved contractor can trim trees near power lines. The message to tree owners is simple: think twice before you arrange to trim or fell trees yourself. The safety risks for you and your neighbours are too great. Power lines range in voltage from 230 volts to 220,000 volts - they all have the potential to kill. You could also be liable for any damage that occurs to the lines network or third parties, in the event of an accident during tree trimming.
