Besides, if you can have a *duck* drowing in one of those springs, then I
would think that _anything_ could die in a fresh pool. A fresh pool might
forcibly suck its victim down, drowning it no matter how good a swimmer it
would otherwise be.

  Umm, a duck *can* drown.  Easily.  You see, a duck likes to eat fish, so
they dive underwater to catch the fish.  If a duck dove for a fish in that
pool and got itself caught while underwater it would drown.

  Simple when you think about it.