A couple thoughts to boost the area a bit:

Make the waterfall climbable to a ledge were we can dive off. Diving as a skill/feat/ability could be kind of neat, there are many different kinds of dives, and the waterfall may give enough height to allow us to try.

Allow a swimming path from the end of the river back to the enclave docks, ideally with some critters, but at least a route to go.

Change the strength of the river current with the season, harder to swim in the Spring, less in the Fall, due to changes in water level.

In the Fall, allow quicksand to form in some spots in the river near the shore. Escape skill can be learned (by throwing a rope to a tree, etc.) by getting out.