It's a water fountain. A very pretty and eye-catching water fountain but still a water fountain. If it were included in a performance of some kind, or if the fountain changes during specific times (example: every 30 minutes) to do something special with the water, then perhaps it could be called a water show. However, if it is just a well made fountain in city or at a vacation resort, etc, it is just a water fountain.

It's an interesting question. Water fountain or fountain (a bit vague) are correct for a static fountain. If it had sculptures it would called a water fountain with sculptures or maybe a sculpture fountain. If there is an element that is show-like, for example lights, music, motion, etc., then it would qualify as a show, a water fountain show or fountain show. The show could be scheduled, random, or constant, and still qualify as a show. Water show, unfortunately, is too broad. It could mean a show of boats on a lake, like the annual Chicago Air & Water Show. Water show alone does not refer to a water fountain show effectively enough to be recognized. Though, to be frank, I think many people will use it that way and rely on context to make it clear. Notably, Misaka Park, Japan, names theirs, Misaka Park Water Show. They appear to be almost entirely unique, globally, in their use of this name, including in English, French, and Spanish. It's such a minor thing, without any hard rules, I doubt anyone would give it a second thought, however, "unusual," in the native English speaking world.

I don't actually think the word "water" is necessary in front of fountain. But if it's changing constantly with music and lights, it's more that just a fountain. Probably a water show.