I swam in southern lakes that were pretty stagnant. It is a wonder that I ever survived childhood.
Me too. They may not have been really stagnant though.
In Louisiana, there was one creek with a deep spot about 20 x 20 and a good cliff for jumpin'. I heard they put salt blocks in the creek to drive off the snakes.
We used to hike down the creeks in the National Forest near the house all the time. I can remember stepping in quick sand and having to find a branch to fish a shoe out of it. We'd carry our rifles just in case.
Then there were a couple of lakes we used to frequent. But the lakes had fish in them, so I guess they weren't too stagnant. I remember the health department did check the lakes to make sure they were fit to swim in, but I bet they didn't know about brain eating amoeba back then.