Trees within four metres of a power line may only be cut by a contractor the network operator has approved. We hold that approval on both networks covering the lower North Island.
The short version
New Zealand law treats trees near power lines as a separate class of work. Under the Electricity (Safety) Regulations 2010, work within four metres of network lines may only be carried out by a contractor the network operator has approved. Do it yourself and you risk prosecution — and, far more seriously, electrocution.
Keeping trees clear of lines is the property owner's legal responsibility under the Electricity (Hazards from Trees) Regulations 2003. That responsibility doesn't move just because the tree was there first, or because it self-seeded.
Arb Innovations holds approval on both networks that matter across the lower North Island. That means one contractor can handle your trees whether you're in Karori, Carterton or Linton.
Wellington Electricity
High voltage and low voltage — close work within 4 metres
Wellington Electricity places contractors in tiers according to what they are authorised to work on. We hold the top category, covering both high and low voltage close work. Only three contractors are listed in that category on their current schedule.
Powerco
Listed across three network regions
Powerco publishes the contractors approved to work near its network. We are listed for the Wairarapa, Manawatū (including Taihape and Raetihi) and Whanganui regions, and can be engaged directly against a Cut or Trim notice.
Purpose-built plant
Our Marooka elevated work platforms are bespoke units — specified and built for live line vegetation work rather than adapted from a general-purpose machine. Insulated boom, tracked undercarriage, and a working envelope that suits the clearances this work has to be done to.
The specification is what earns its keep on a hard site. Tracks put the platform on wet ground, steep berms and soft paddocks a truck-mounted unit simply cannot reach, and get it there without cutting up the surface on the way in.
The fleet
Running several platforms means a job does not wait on one machine coming free, and a long span of line can be worked from both ends at once.
They mobilise off our own yards at Judgeford, Waingawa and Linton, so getting a machine to the Wairarapa or the Manawatū is our scheduling problem rather than a hire company's availability.
Clearance zones
Three zones apply to every overhead line, and they widen as voltage rises. The growth limit zone is the space no part of a tree may enter. The cut-back zone is how far back we cut so the tree doesn't re-enter that space before the next inspection. The notice zone is the distance at which the network operator will write to you.
| Overhead line voltage | Growth limit | Cut-back | Notice |
|---|---|---|---|
| Low voltage lines (230–400V) | 0.5m | 1.5m | 2.5m |
| High voltage (6.6kV) | 1.6m | 2.6m | 3.6m |
| High voltage (11kV) | 1.6m | 2.6m | 3.6m |
| High voltage (33kV)* | 2.5m | 3.5m | 4.5m |
| High voltage (50–66kV)* | 3.0m | 4.0m | 5.0m |
| High voltage (66kV or more)* | 4.0m | 5.0m | 6.0m |
* Clear to the sky: the growth limit zone for these lines reaches vertically with no upper limit. Trees protected by a district plan are excluded from that requirement. Spans longer than 150 metres carry additional clearances again. Figures published by Powerco; the Wellington Electricity network applies the same four-metre rule for close work. If you're unsure which applies to your property, ask us and we'll confirm it.
Planting
The cheapest tree work near a line is the tree nobody planted under it. Powerco recommends keeping new plantings at least 30 metres clear of power lines, and choosing species whose mature height suits the distance you actually have.
Species selection catches people out. Something sold as a garden tree can still make twelve metres, and the label rarely says so. Ask us before it goes in the ground rather than after it becomes a notice — that conversation is free.
Coming changes
The Electricity (Hazards from Trees) Amendment Regulations 2026 came into force on 23 July 2026 and phase in over the following two years. Three changes will matter to landowners, and none of them apply yet except the first:
Dates and detail here follow the Government's announcement and Cabinet papers. The networks will publish their own guidance as each stage commences, and we will tell you what actually applies to your property when we quote it.
Cut or Trim notices
Network operators inspect their lines and write to tree owners when something is encroaching. The letter tells you what's required and by when. There are two kinds and the difference is money.
Powerco calls this PPPD: Powerco pays, Powerco does. If those trees have not been cut before, the cost of the first trim is covered. Contact the contractor named on the notice and they'll arrange it with you.
Called TOP: tree owner pays. Once a tree has been cut once, keeping it clear is on you. You may approach any approved contractor for a quote — including us.
Don't sit on it. Powerco advises that failing to act within the timeframe can bring a fine of up to $10,000 and a further $500 per day until the work is done, plus liability for any damage your tree causes to the network.
Bring us the notice. We'll read it, tell you which type it is, quote the work, and where a shutdown is needed we'll talk you through arranging it with your retailer.
How we work
Close work
Working inside the approved distances means every cut is planned around where the conductor is, not just where the branch is. The platform is positioned so that the operator, the saw and the limb being cut all stay outside the limit for the voltage on that line.
That is precisely why network operators approve contractors individually instead of accepting any qualified arborist.
Reach over proximity
Close-quarters cutting near a line is pole saw work, and these are not ordinary pole saws. They are hydraulic, insulated tools built specifically for vegetation work around live conductors — the insulation is part of the safe working system, not an accessory to it.
They also keep the operator further from the conductor than a handsaw ever would, and let the cut be made at the angle the branch needs rather than the angle the bucket allows.
Small material drops clear. Anything with weight in it is roped and lowered — nothing comes down through a line.
Emergency
Treat every downed or low-hanging line as live. Keep people, children and animals well clear, don't attempt to move anything, and don't drive over a fallen line.
Once the network operator has made the site safe, we can clear the tree. If a storm has brought a tree down across your property and lines are involved, call the network first — then call us.
Common questions
No. Under the Electricity (Safety) Regulations 2010 you can be prosecuted for carrying out tree work yourself within four metres of network power lines. Any tree within four metres must be cut by an approved contractor. Beyond four metres, any qualified arborist may carry out the work.
There are two kinds. A 'Powerco pays Powerco does' (PPPD) notice means it's the first time those trees have needed cutting, and Powerco covers the cost — contact the contractor named on the notice. A 'Tree owner pays' (TOP) notice means it's a second or subsequent cut and the cost sits with you as the tree owner, so you may approach any approved contractor for a quote. We are an approved contractor for Powerco in the Wairarapa, Manawatū and Whanganui regions.
If you don't act within the timeframe given, Powerco advises you can be fined up to $10,000, plus a further $500 per day until the work is completed. You may also be liable for the cost of any damage your tree causes to lines or equipment.
Sometimes. Where the work requires it, your electricity retailer — the company you pay your power bill to — arranges a temporary disconnection. They need at least 24 hours' notice. We'll tell you at quoting stage whether it's necessary and talk you through arranging it.
It depends on the voltage. For standard 230–400V lines the growth limit zone is 0.5m and the cut-back zone 1.5m. For 11kV high voltage it's 1.6m and 2.6m. For lines of 66kV and above it rises to 4m and 5m. The full table is on this page.
You may be able to declare 'no interest' in the tree. That hands responsibility to the network operator, who will then trim or remove it at their discretion — or may choose not to work on it at all. Powerco and Wellington Electricity both have a process for this.
Keep people and animals well clear and call immediately. Powerco's emergency line is 0800 27 27 27. In the Wellington Electricity network area call their fault line. If anyone is in danger, call 111. Never approach a downed line.