The council published the warning on social media on Thursday, advising people against entering the water in spite of the recent soaring temperatures.
In the message, the council said it had noticed a number of people swimming at the waterfall in Mertert over the last few days, including schoolchildren from abroad. The area is not monitored by lifeguards and there are a number of potential risks, including mud, rocks and the concrete dam. In addition, there is no guarantee that the river water is free of contamination.
The council said it would not take any responsibility for issues incurred, warning swimmers of potential risk to health.
