Adding the note sheet is actually a nice idea! It really helped me going trough the song a lot more and pointed out things I might have missed otherwise.
Due to the 3/4 time signature and the instrumentation I had immediate swan lake waltz vibes. Which was kinda fitting for a hot spring town theme. I pictured some swans/ducks swimming on the springs.
As a German I might be heavily influenced by a piece called "peter and the wolf", but to me wood winds are generally associated with birds. So the piccolo did it's thing strengthening the bird image I already had in my head.
You wrote you used the steel drums for the watery feeling, but since it was kind of low tuned it sounded more like frogs to me. Which was still fitting.
Temple-blocks where really fitting as water drops, but I was missing the "hotness" a little bit. Don't really know how I would add this. Maybe some rides or cymbals in general to have something that sound like steam?
Structure wise I really enjoyed it. It didn't get repetitive and yet the individual parts felt very well connected.