An alien invasion threatens reservoir
A HIGHLY invasive weed is causing a potentially expensive headache for Irish Water as it threatens to spread through one of Dublin’s reservoirs.
Japanese knotweed has been spreading rapidly at Bohernabreena Reservoir, south Dublin, for several years and if Irish Water is to get rid of it, it will be a very expensive fix.
Previously the water utility company erected signs alerting people of the presence of the plant and warning them not to cut it after people were caught taking samples with the intention of introducing it to their own gardens.
Further action is now to be taken after a spokesman for Irish Water told the Irish Mail on Sunday it plans to start spraying and/or injecting the plants this year. He also said the company envisages this programme to eradicate it completely will take a number of years.
An Irish Water spokesman said: ‘In carrying out this programme, we are committed to complying with all relevant guidelines in relation to Japanese knotweed to protect the environment and public health.’
However, locals – who use the reservoir as an amenity and contacted the MoS about the issue – have expressed concern about the potential for weed-killing chemicals to leak into the ground water, and subsequently the city’s water supply.
Japanese knotweed is a non-native species of fast-growing plant that has spread massively over Ireland in the past few years. Cuttings from either the cane or root of the plant can form entirely new colonies of the weed. Soil within 7m of the plant can also be contaminated by its sprawling root system.
The robust plant can survive in water and it is feared cuttings of the plant might travel downstream from the reservoir and infestations of the dreaded plant might extend to Dublin city centre.
The presence of the weed has already been reported in Ballsbridge in Dublin and homeowners along the course of the River Dodder are at risk of being invaded by the Japanese knotweed, which can wipe thousands of euro off the value of their properties.
If left untreated, the fast-growing weed can penetrate foundations and walls and compromise the structure of buildings.
In the UK, estate agents are required to alert potential buyers of the presence of the plant at a property and landowners can be held liable for costs incurred as a result of the weed’s removal.
Laws in Ireland are more relaxed. While the control of the plant is a matter for landowners, a government license is required for anyone who intends to move or transport Japanese knotweed.
The cost of spraying an infected area of just 100sq m can range from €600-€800.
In the UK, around €80m was spent on removing Japanese knotweed from the London Olympic site through stem injection.