RESIDENTS were left mystified over the weekend after Thornbury’s popular Streamside Walk was turned bright green.

Reports began circulating on Friday after people began spotting the pigment of the water had turned the unusual colour, with many concerned that it might have been pollution.

A number of sightings had been made between Maple Avenue and the Scout Hut near Manorbrook School.

The Gazette understands, following a series of enquiries with South Gloucestershire Council and the Environment Agency, that the colour came from a special non-toxic and degradeable dye that is used by environmental groups to track the flow of water in drains.

While no body has yet claimed responsibility for the dye, a spokesman for South Gloucestershire Council said that they had been in contact with Wessex Water who visited the area and confirmed it was not pollution.

The incident has also been referred to the Environment Agency, who are the body responsible for the pollution of water courses.

The South Gloucestershire Council spokesman said: “Our environmental health team were contacted on Friday evening regarding unusual coloured water that had been spotted in the stream at Maple Avenue in Thornbury.

"We immediately referred the matter to Wessex Water, who visited the area and confirmed that it was not thought to be a pollution incident and instead resulted from the use of dye or ink.

"The incident was also referred to the Environment Agency as the body responsible for pollution of water courses."