Well, this "people" says it is coming from the river because it IS coming from the river. I can't speculate on if it is the river alone or if there is sewage overflow in it. I can say with certainty that I have swam in it and didn't get sick. I can also say with certainty that on two occasions Smokey has become sick while in Negril. Both times gastrointestinal issues, one time really bad. Is there any connection? I have no idea. Nor would I unless I hauled my ass up the river and checked out what happens at the sewage ponds when a heavy rain comes down. I do know, with certainty, that the river flows through a peat bog. I know for a fact that water coming from a peat bog is going to be dark brown. I would venture a guess, only a guess, that the treated sewage water is not sanitized to an acceptable level most of the time but that is pure speculation on my part. Speculation based on the half assed way Jamaica does most things. I know that the waste treatment plant was upgraded a couple of years ago because of overflow onto surrounding land. Of course that overflow made it's way to the river then the sea. I have no idea if they actually corrected the problem or not. So my worry would not be the color of the water at any certain time it would be the strong possibility that MOST times the levels of nasty things are too high. THAT is always my issue---- folks seeing the smoke but never the fire.
And--- the LAST person/persons I would ever listen to about anything would be a Jamaican working on or near the beach. Whether they called it river water or shit water I would never listen to them. If I believed half the crap Jamaicans have said to me, well, I would be an idiot. Why would I be an idiot? Because I would believe I would get a yeast infection from hanging panties out to dry on a windy day. I would believe that Aloe could cure anything up to and including a broken neck. I would believe that eating potatoes makes your d*ck dead. I mean just ask some Jamaicans about anything, even if they have no clue they will pontificate till the cows come home.