I stayed in a kampung
when I was younger. The longkang was one of our playgrounds.
The canal had dry banks. We would run up and down the canal walls.
But yeah, we never played there when it rains.
Later in my life (we moved to a HDB flat), I had two friends who
drowned while playing along the canal. She fell into the canal and
drowned. Her brother tried to rescue her drowned too. Yes, the
current is very strong, so don't overestimate your swimming
ability.