Case Study - River Roe, Limavady,

Northern Ireland

Works commenced in June 2009

An initial survey was carried out along 12.5km of river to identify and
document the extent of invasive weeds on the site. Infestations of
Japanese knotweed, Giant Hogweed and Himalayan Balsam were
present on both sides of the riverbank. The project was part of a flood
defence improvement scheme following 3 significant flood events in the area.

A detailed report of recommendations was produced for the Client and chemical treatment commenced in June 2009. Initial works consisted of a Glyphosate herbicide treatment to all areas of infestations. JKSL identified the areas of work activity with a series of high visibility marker poles. These were moved as necessary to ensure that areas involved in direct work were discretely identified and where necessary the appropriate cautionary and/or warning signage was used. 

In November 2009, JKSL returned to cut the existing stands of last season's growth of Knotweed. Each stand area was cut back leaving stumps in order to ensure no root/crown material was included in the stockpile. The cut material was then transported to an area on site where it was disposed of through controlled burning. The Japanese knotweed crowns were injected with a Glyphosate based herbicide and left exposed in order to increase the possibility of frost damage to the plant. 

The site will be re-visited twice a year over a period of 5 years to monitor and retreat any re-growth.

The works to date are showing to have had an excellent success rate. There is a dramatic difference to the river banks. The river bank is beginning to regenerate allowing a new variety of species to establish along the banks.