The court ruled that a landowner’s knowledge of the presence of Japanese knotweed on its land in close proximity to other properties, along with actual or constructive knowledge of the risk of damage and loss of amenity to adjoining properties by encroachment of Japanese knotweed, and the landowner’s failure reasonably to prevent such interference with the adjoining owners’ enjoyment of their properties gave rise to a cause of action in private nuisance.
The claimants in the case were the freehold owners of two adjoining semi-detached bungalows in Maesteg, south Wales. The defendant (Network Rail) owned the land behind the claimants’ properties, comprising an access path bordered by a post and wire fence leading to an embankment that dropped down to an active railway line. The rear walls of the claimants’ properties immediately abutted the path owned by the defendant. On the embankment was a large stand of Japanese knotweed that had been present on the land for at least 50 years. The court found that since 2012 the defendant had failed to carry out its obligation as a reasonable landowner to eliminate and prevent interference with the quiet enjoyment of the claimants with their properties and that that breach of duty had caused a continuing nuisance and damage.
Comments were made; “Japanese knotweed is pernicious and very difficult to eradicate. Its presence on an adjoining property or land parcel can significantly affect the value of your property”.