If a tree falls in the woods… is there liability?
There are lessons for both network operators and forestry companies/owners arising from a recent Court of Appeal  case. The case clarifies that tree owners can be held strictly liable for damage caused by tree falls.
The case was an appeal from a High Court decision that a Forestry Co  was liable to a Network Operator  for damages caused by falling trees.
A registered interest would have placed the Network Operator in a stronger position
The Network Operator had to resort to claiming damages under common law, and going through a comparatively complex court process.
With the benefit of hindsight, had the Network Operator taken a registered easement when it began its operations (rather than relying on rights under law), the easement may well have provided:
- that damage caused by the tree falls was a clear breach by the Forestry Co, and therefore established the Forestry Co’s liability; and
- an easier course for the Network Operator to obtain injunctive relief from the Court.
Good practice for forest owners not a good enough defence
Forestry land owners and forestry companies should note even though the Forestry Co exercised good industry practice during the relevant period and complied with the applicable law – the Forestry Co was still found to be strictly liable for damages due to the height it permitted its trees to grow in relation to nearby utilities.
Trees had grown tall enough to hit the lines when they fell
The Network Operator ran two lines through the forest. It was assumed the Network Operator’s lines had been originally established under public works or electricity legislation, and existing works of this nature can continue until the owner of the works decides to remove them. 
There was a non-planting corridor around the lines, but the trees had reached a height that meant falling trees reached the lines.
Over a period of years, a number of trees fell causing damage to the lines and disruption to customers. The cause was root plate failure (where the roots were insufficient to anchor the trees to the ground), which commonly occurs following adverse weather events. The trees were otherwise healthy and could not be identified as fall risks in advance of the falls.
The High Court had found the Forestry Co strictly liable for the damages both on the basis of nuisance, and under Rylands v Fletcher (a common law rule that establishes liability for something ‘escaping’ land).
However, the High Court declined to grant an injunction or find that the Forestry Co had been negligent.
Both the Forestry Co and the Network Operator (by way of cross-appeal) appealed the High Court decision.
Forestry Co still liable for nuisance on appeal
The Forestry Co claimed that because:
- the tree falls had not been because of mismanagement; and
- it had complied with the relevant laws governing the required distances of trees from utilities, the Forestry Co should not be liable for the damage.
The Court however disagreed, holding that:
- there was inevitability of tree falls in bad weather (evidenced by earlier incidents), and by allowing the trees to grow to a height where they would cause damage if they fell, the Forestry Co had “created a state of affairs on its land that caused an unreasonable and continuing interference with Unison’s [the Network Operator’s] line”; and
- it was not a defence that all reasonable precautions had been taken, and the Forestry Co was therefore liable for damages.
Other claims dismissed
The Court of Appeal considered and dismissed the claims under Rylands v Fletcher and also the claim that the Forestry Co had been negligent. In relation to the Rylands v Fletcher claim, the Court determined that liability under this rule required an “unnatural” use of land, and (in this scenario at least) the growing of trees in a forest was not an unnatural use of land.
Co-authored by Jack McCaw, a Senior Solicitor in our Property team.
 Nottingham Forest Trustee Ltd v Unison Networks Ltd –  NZCA 227.
 Nottingham Forest Trustee Limited, Roger Dickie (N.Z.) Limited, Forest Management (NZ) Limited, and Nottingham Forest Partnership.
 Unison Networks Limited.
 Section 22, Electricity Act 1992.