For years my answer would be yes. For instance, I can clearly remember the bridges over the rivers in New Sorpigal, Ironfist, Free Haven etc.
The only problem is that these water bodies are no rivers. They have no spring and they're on completely level ground. All of them start in a sea and they go on in a while until they just stop and form some kind of a pool or a "dead end". So they could be perhaps called troughs but definitely not rivers .
Do you know about any "real" river in worlds of MM? A river that would have a spring and go downhill into the sea? I'm just wondering but now I think there is none (except perhaps in MM8 which I haven't played yet).