Wakulla Spings and the Borders of the Fantastic

I read the novella Wakulla Springs by Andy Duncan and Ellen Klages because I have enjoyed the work of Andy Duncan in the past.  And this is a good story too, well-written, covering four generations of an African-American family and their ties to the Wakulla Springs jungle in northern Florida, where some films were made like Creature from the Black Lagoon, and some of the Johnny Wiessmueller Tarzan films. This novella was nominated for a Nebula Award, and a Hugo Award, and won a World Fantasy Award. The question is not whether this story is award-worthy, but why was it deemed eligible for such awards when there is no fantasy elements at all in the story?  Probably the answer is that the authors are known for fantasy and science fiction, and the making of a fantasy/science fiction film (Creature from the Black Lagoon) is at the heart of the story. Still, that shouldn't be enough for eligibility even given the fact that mainstream award-givers would pay no attention to it.  A good story,  but a frustrating scenario surrounding it.