Enchanted Stream

[Gwathagor]

Personally, I doubt that anybody enchanted the stream at all. You might say that the presence of magical beings in the forest rubbed off on the stream, but I doubt it was anything that direct in Tolkien's mind. The Hobbit is much more of an old faerie story than LotR (which is more complex and mythological), and in faerie stories things frequently do not have any clear reason for the way they are.

Tolkien's thought process probably went something like this: Elves and other magical creatures live in the forest. Therefore, it is a magical forest. Therefore, the stream in the forest is magical.