First, a private nuisance may be and usually is caused by a person doing, on their own land, something which they are lawfully entitled to do. Their conduct only becomes a nuisance when the consequences of their act are not confined to their own land but extend to the land of their neighbour. This can occur either by encroachment, physical damage to that land, or, interference with the neighbour’s enjoyment. However, it is well recognised now that omissions, as well as acts, or activities, can found a nuisance. Today, a landowner owes a measured duty in both negligence and nuisance (ie the duty in Leakey v National Trust) to take reasonable steps to prevent natural occurrences on their land from causing damage to neighbouring properties. Further, in determining