I certainly wouldn't have let my children stand right by a fast flowing river unless I was right next to them or they were standing well away from the edge.
When we travelled on boats I used to put reins on the 5 yr old and my ex used to also put a life jacket on them when we were near or on rivers.
sticky labels on apples - remove before washing!
Water Pollution -“ A National Disgrace”? A case for renationalisation?