Neil has a neighbour with unstable pine trees on his property, bordering a shared driveway. On the land on the opposite side of the driveway is a shared power line, not shared by the neighbour. Neil wants to know whose responsibility is it if a pine tree falls across the driveway and breaks the power line.
Answer: This is a tricky one. The first thing to do is find out who owns the power line; there are 30 lines companies in New Zealand and they all have their own rules. In many parts of the country lines crossing private land are the property and responsibility of the landowner but this doesn't apply everywhere.
In the Waikato
WEL Network's maintenance strategy manager John Versluys gets two or three calls a week about this question and says many people don't appreciate or understand the issues.
"It does require an understanding of what the situation is, where the lines are in relation to the property, whose tree it is in relation to the lines on the property - it can be quite complicated."
Sometimes he works it out over the phone, using the company's Geographic Information System or even Google street view. "So I can often get the gist of it by looking at those. If not, I'll go out to the property. The key determinant for me is, is it our line that the tree's impacting and therefore is it our responsibility and take it further. Or is it a private issue to be dealt with."
WEL Networks provides electricity distribution services to the Waikato, and connects some 80,000 customers.
In general, WEL Networks owns the poles and the lines alongside the road but the lines that go across to houses - the service lines - belong to that consumer, he says.
"So they need to maintain them, they need to keep them clear from obstructions, they need to repair them if they're unhappy with their condition."
This is the case in the Waikato. But crucial to Neil's question is what region he is in. There are 30 electric line companies in New Zealand.
"In other places there are some different rules," says John. "For instance, Orion, which is the lines company around Christchurch, has decided to take responsibility for service lines, even though they don't own them in a sense. Maybe they feel rather than face the hassle or uncertainty of people looking after them, they'll just do it. So there are some different ways that lines companies deal with it."
He says the key point is who owns the line and who owns the tree. "If…it's your lines, and someone else owns the tree - the two parties need to come to an agreement."
It can be tricky. In the case of a line going down a driveway jointly owned by the people it is supplying, it can be a joint responsibility. However - "The bottom line is that it's the tree owners responsibility to keep it free of the lines."
This is no different from a neighbour's tree knocking against someone else's house or damaging pipes on their property. "It's a nuisance, and you have the right to expect that your assets are left undisturbed by anybody else's property… ultimate responsibility is with the tree owner."
Relations with the neighbour
The problem then arises when the owner of that tree is not co-operative.
"And that's where a lot of issues arise." One person asks the other to trim the trees and keep them clear of the lines and often doesn't get a good reception.
John suggests two approaches. "To my mind the only options are to undertake the responsibility yourself…I want my lines to be safe, so I'm going to pay for it, even though it's not my responsibility. Say to the neighbour, will you allow me to do that if I wear the cost. It's not an ideal situation but if you're not getting anywhere it's one way to get it done."
The other way is to explore legal options. "Get a letter from a lawyer to say he is causing a nuisance, if you don't take steps to remove that nuisance I'll take legal action."
Transpower New Zealand owns and operates the National Grid, the network of high-voltage transmission lines and substations. I posed the question to communication manager Adele Fitzpatrick who agrees the first step it to find out who owns the line.
"This may be Transpower if it is part of the grid, or it might be local lines. To find out who the line belongs to, ring our toll free number, 0508 526 369. If it's not ours, we can point them in the right direction. And the line owner should be sending out a contractor or getting in touch with the owner of the trees."
From what she was told she believed Neil would not be liable.
"The tree owner could potentially be liable if they were at fault in some way - for the tree falling over and damaging the line."
It's not so much of a problem for Transpower, she says. "Our pylons are much larger, and therefore trees are less likely to be close to the lines … it is important that trees are kept within the regulated sizes around lines."
This is set out in the company's brochure, Trees and Power Lines, which sets out responsibilities of tree owners and Transpower.
In July 2005 the Electricity (Hazards from Trees) Regulations 2003 came into force. The Tree Trimming Regulations, as they are commonly known, require trees near power lines to be certain minimum distances from the lines - and give Transpower and lines companies the right to maintain lines free from trees or vegetation hazards. John Versluys says however the regulations don't really cover privately owned lines. "They're really focused on lines companies like us, and trees impacting on our lines."
Adele Fitzpatrick says they like to have their own contractors work on the trees. "It's quite a specialist and risky operation."
Transpower will pay for the first cut or trim of a tree, but after that responsibility passes to the tree owner.
According to Powernet, which provides electricity to the lower South Island, trees are the major cause of faults on its networks in times of bad weather.
So - trees can be serious cause for headache. Best to not only keep an eye on them, but also find out who owns the power lines on the property. And take appropriate action.