Japanese Knotweed – A Growing Nuisance

Viewed as an attractive ornamental garden plant when initially introduced to the UK in Victorian times, Japanese knotweed is now regarded as something much more sinister. Unusually aggressive, highly invasive, capable of regenerating from the smallest piece of rhizome, difficult and expensive to eradicate ... It's destructive nature (being capable of penetrating tarmac, building foundations and drains, causing considerable and costly damage to property and infrastructure) is becoming an ever increasing concern for landowners.

The presence of Japanese knotweed can have an adverse effect on the value, marketability, mortgageability and insurability of a property. Although the hazardous weed is more prevalent in urban areas, growing on derelict land and also along railway lines and canals, where it was historically utilised to stabilise embankments, it can be found in all parts of the country affecting all types of land, including gardens of residential properties.

It may therefore be considered surprising that there is no statutory positive obligation to eradicate or even keep Japanese knotweed under control. However, landowners and occupiers could face criminal and civil liability for the encroachment of Japanese knotweed onto neighbouring land or the adverse effect its presence may have on the amenity of an area under a myriad of legislative provisions under the Wildlife and Countryside Act 1981, the Environment Protection Act 1990, the Town and Country Planning Act 1990 and the Anti-social Behaviour, Crime and Policing Act 2014 or through a claim for private nuisance.

Depending on the offence, penalties can include fines (in some cases unlimited) and even imprisonment. Since the coming into force of the Infrastructure Act 2015, environmental authorities also now have the right, in some circumstances, to compel landowners to manage invasive species such as Japanese knotweed by making Species Control Orders.

Perhaps more interestingly, and topically in view of the decision in the County Court case of Waistell v Network Rail Infrastructure Limited earlier this year, a claim can be brought by an aggrieved party against a neighbouring owner or occupier if the presence of Japanese knotweed on the neighbour's land causes damage to or interference with the use and enjoyment of that party's land.

That case involved separate claims brought by the owners of two properties in South Wales abutting an embankment owned by Network Rail. Japanese knotweed...