I'd have to look for it, but there are two threads on rivers specifically in the General Forum and I think, the Mapping Elements Forum, however I couldn't find them, though they are a couple years old. Perhaps one of the CL's can find it and link it into this thread. These discuss rivers and all the various anamolies that could exist and those that could not, along with why. They are worth reading for general knowledge and future river designs for anyone.

GP