Neighbourhood disputes over tree roots

January 5, 2018

Your neighbour has a fig tree. You notice that your drainage pipes are blocked. You get a plumber to inspect and are advised that tree roots are causing the blockage. An arborist tells you that the tree roots are from a fig and that the only fig tree is your neighbours. You decide to sue the neighbour for the costs of your plumbing repairs.

In a recent QCAT case, that is what happened. You may think it an open and shut case, but not so.

The Tribunal held that the roots did not break the drainage pipes. That was caused by age and ground movement. Once the pipes cracked, then the tree roots sought out the water which was inside the pipes. So the roots did not cause the problem and the aggrieved neighbours failed in their claim for damages.

This raises a common problem with evidence in a Court. It is easy to jump to an obvious conclusion by confusing causation with consequential identification. The Tribunal said that to hold the neighbour responsible would be like the owners of a coal mine suing the owner of a canary which had alerted them to a gas problem in their mine.