The owners of for four homes in Ammanford have won tens of thousands of pounds in a claim over Japanese knotweed that has been growing on the properties for nearly a decade.
The residents, who all live in the same road, settled for a combined £42,500 in damages from Network Rail, which maintains Britain's railways.
Property owners are entitled to make a claim if the plant grows up to a metre onto a piece of land, according to High Street Solicitors, which represented the homeowners.
Japanese knotweed is a weed that spreads rapidly and is notoriously difficult to get rid of. In winter the plant dies back to ground level but by early summer the bamboo-like stems emerge from rhizomes deep underground to shoot to over 7ft tall, stopping all other plant growth.
It is an offence to cause Japanese knotweed to grow in the wild and the presence of the plant on a property can take off 10% from the price. It can also make a property unsellable, as many lenders are unwilling to offer mortgages on such properties.
If you have any Japanese knotweed on your property you are legally required to disclose this in the sale process.
In the successful claim against Network Rail, the four properties backed onto the railway line and had infestations growing as high as 8.2ft.
Property owners are entitled to make a claim if the plant grows up to a metre onto a piece of land, according to High Street Solicitors, which represented the homeowners. It added that there needs to be visible encroachment onto the homeowner's land to lodge a claim, and the property itself needs to be within about 7m of the plant to have a strong case.
Joann Cameron, of the law firm, told the Daily Telegraph: "If you have Japanese knotweed on your land this would cause an immediate diminution of property value and become apparent when and if you decide to sell.
"It is extremely important that the plant is eradicated and treated professionally, ensuring that you obtain a 10 year back guarantee when treatment has been carried out."
News for your area by postcode:
A Network Rail spokesperson said it understood Japanese knotweed was a "real concern" for its neighbours.
"We will always take action to manage the plant whenever it is identified on our land and will look to work constructively with our neighbours to stop it spreading," they added.
The weed, which can push up through cracks in concrete and walls of houses, affects around 5% of homes in the UK, either directly or through a neighbouring property.
According to Environet Cardiff is one of the hotspots for Japanese knotweed along with Bolton, Bristol and St Helens.
