This question comes from a correspondent on the NSW Central Coast:
i would like to find out the responsibility of councils regarding trees that cannot be removed but poses a danger to people or properties. Can council be sued if a tree say destroys property. If not why should council have the power to punish those who cut trees yet they cannot be liable for damage caused by the same trees.
Local governments are indeed governments; they are not the same as individuals Graham Barclay Oysters v Ryan (2002) 211 CLR 540). Councils have the power to make tree preservation orders under various Local Environment Plans under the Environment Planning and Assessment Act 1979 (NSW). They have the power to do that as the preservation of trees may be in the public interest even if they are not in a person’s individual interest.
The real issue in this question is, I would suggest, a dispute as to whether or not the trees are dangerous? Another critical question is ‘who owns the tree?’
If the tree is a council tree and the risk is to a neighbouring property, then council would be liable, like anyone, if it failed to take reasonable care of its trees. That does not mean council has to know the up-to-the-minute state of every tree, but it would, ideally, have some sort of inspection program and a policy regarding tree replacement given the type of trees and their expected life span.
If a neighbour thinks the tree is unsafe they should let council know which would put them on notice of a problem and would, one might expect, cause them to at least arrange an inspection.
If the tree is a private tree and the person wants to remove it but is prohibited, the question is ‘are they really prohibited?’ If there is a tree preservation order in place it will provide a means to apply for permission to remove the tree. If one were to make an application one would need to support it with evidence, ideally from an arborist, that the tree is indeed, unsafe.
In Timbs v Shoalhaven City Council  NSWCA 81 a council was liable for failing to properly consider a request to remove trees that were dangerous. The issue arose because a council employee, when asked if trees could be removed, did not advise the homeowner to make an application, rather he said that the trees could not be removed without permission (which was true). By not giving correct advice or taking steps to inspect the trees the employee was negligent. If, however an application had been made, the trees had been competently inspected and a decision made, in good faith, not to allow the removal of the trees there would have been no liability even if the tree had fallen in the wind.
Liability does not arise because of bad consequences but because of a failure to take reasonable care. One might assess a risk as very low and not take action, but even a low risk can occur so the fact that it does occur does not show that the assessment was wrong, or that other action should have been taken.