The Rule in Rylands v Fletcher
When is the Rule in Rylands v Fletcher Applicable?
A defendant is liable under the rule in Rylands v Fletcher (1866) LR 1 Exch 265 if:
- He is the occupier of land;
- He uses that land in a non-natural way;
- As a result of this a dangerous thing escapes the land;
- The escape of that dangerous thing causes damage to another; and
- The kind of damage caused was reasonably foreseeable.
What is ‘Non-Natural’ Use?
Use is non-natural if the defendant was doing something which he ought to have realised, judging by the standards of the relevant place or time, was ‘extraordinary’ and ‘unusual’ and which gave rise to an exceptionally high risk of danger or mischief if there was an escape: Transco v Stockport Metropolitan Borough Council  2 AC 1. It is not relevant that an escape was unlikely or that the defendant’s use was reasonable. Relevant factors indicating the use is (according to the House of Lords in Transco) natural include:
There is statutory regulation that appears to provide an ‘exhaustive code’ for regulating the activity.
The claimant might reasonably be expected to insure against the risk himself (if possible at reasonable cost).
The risk posed by the activity is no greater than similar ‘ordinary’ activities.
The defendant was under a statutory duty to engage in the activity.
What is a ‘Dangerous Thing?’
The definition of dangerous is very broad, covering anything which has the tendency to cause harm. However, an activity will only be dangerous if it tends to pose a risk of harm if used in the way the defendant is using it. For example, storing water behind a dam is dangerous, but bringing water onto land as part of ordinary domestic water supplies is not: Rickards v Lothian  AC 263.
The dangerous thing must have been ‘brought onto the land’: this excludes liability for accidentally lit fires. See: Gore v Stannard  QB 1.
What is an ‘Escape’?
Something ‘escapes’ from land if it moves from a ‘place the defendant has occupation or control of’ to a ‘place which is outside his occupation of control’: Read v Lyons  AC 156. If the dangerous thing only causes harm within the defendant’s land, therefore, there is no escape.
When is the Damage ‘Reasonably Foreseeable’?
The rule in Rylands v Fletcher has been classified by the House of Lords in Cambridge Water v Eastern Counties Leather  2 AC 264 as a species of nuisance. This means that the type of harm suffered must be reasonably foreseeable. There is no requirement that the escape is foreseeable, however.
The following defences are relevant to liability under the rule in Rylands v Fletcher:
Act of God
This defence applies where the escape was caused by natural causes which were entirely unforeseeable: Rickards v Lothian  AC 263.
This defence applies where the cause of the escape was the deliberate act of the third-party over whom the defendant had no control and whose intervention was not a ‘reasonable and probable consequence’ of the defendant’s actions which he ought to have guarded against: Perry v Kendricks Transport  1 WLR 85.
Since the rule in Rylands v Fletcher has been characterised as a species of nuisance, the claimant can only claim if his interests in land have been damaged: Transco v Stockport Metropolitan Borough Council  2 AC 1. The other rules relating to claiming remedies in nuisance also presumably apply.