I'm not going to argue the point, but, as far as I know all the water in the developed areas of WDW are connected. They would almost have to be in order to maintain drainage and balance to the water control systems in the resort. And like I said before... alligators do not need water to get from one place to another. They are perfectly capable of crossing land.
One doesn't have to have a computer to know that, all they have to do is occasionally pay attention to the outside world that isn't necessarily showing up on their SmartPhone screen. The first time I traveled from upper, upper New York State to Florida was in 1962 and I knew about alligators, snakes and other critters in Florida. There were no such things as computers or anything other the old dial phones. And I was only 14 or so.