Back when I had to cut short one of my runs because a group of people were beating this poor thing with a stick. I understand people are afraid of water snakes but if you don't go harrasing it won't bite you.
This poor animal was so desperately trying to get away, I emptied my bag, corraled it in a tree corner, and bagged it to make sure it didn't have broken ribs.
After a checkup and some water, we relocated it somewhere it wouldn't be harrased.
Sometimes you have to intervene.