“My land joins forestry lands. The flow of water from drains surrounding one half of my land flows into the forestry land and into a local river. The drain has not been cleaned for over 20 years. Are the owners of that land obliged to keep drains cleaned or what conditions do they have to meet? The drains on the other side of the land flow through a number of neighbours before reaching their main outlet. Four out of five neighbours have agreed to clean the main drain but one neighbour is refusing. We are willing to cover the associated costs for his parcel between us but he does not want to let the drainage go ahead. Is he within his right to do this or is he required not to obstruct the flow of water?”

This is an issue that affects many landowners, especially at this time of year. The law is rather complex as it depends on the circumstances of the case.

Different rules apply depending on whether the drains are natural or whether they were created artificially. Where water naturally drains from one property to another, a natural right of drainage exists under common law. However, the channelling of water by a pipe or other artificial means on to land where it would not naturally flow can only exist as an acquired right or in legal terms as an easement.

It is not clear from your query whether the drains are naturally occurring or whether the water was channelled by artificial means. Consequently, I will set out the law as it relates to both situations.

Natural rights of drainage under common law

In a situation where water naturally drains from one property to another, the owner of land bounding a natural river or stream can protect against flooding of his lands by banking a river, for example.

Equally the owner of lower lands can take action to pin back or stem the flow of water. If water on the higher land naturally passed on to the lower land, the owner of that lower land does not necessarily have a cause of action against the higher landowner in nuisance or trespass if the natural flow of water floods his lower lands. However, he can protect his lands by making a barrier even though this may cause damage to the higher landowner.

However, an action to pen back the water must be no more than is reasonably necessary to protect the lower landowner’s own enjoyment and he must not act for the purpose of injuring the higher landowner. A lower landowner may, however, have a remedy in negligence where the higher landowner fails in his duty of care to do what was reasonable in all the circumstances to prevent a large and dangerous quantity of water on his land causing the lower landowner damage.

For example, if a stream is known to flood, if the risk of flooding to the lower landowner can be reduced by the higher landowner cleansing and scouring the watercourse, the higher landowner will be in breach of duty if he does nothing at all. But if the only remedy is substantial and expensive works, he may discharge his duty by telling his neighbours that they are free to do the works at their own or at a shared expense.