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Just a specific type of dance choreography. The "Step Up" series of films seemed to sometimes include a "water dance" of the type you mention. Nothing found as far as a trope name.
PCD. I refer to those like Beyonce's Live performance of Freedom, Sia's Rainbow with Maddie Ziegler and a Lindsey Stirling's Master of the Tides.
Well, I've never seen any of those. You may be the best person to create a new trope for water dance routines. If you don't want to, check websites for these performances and see what their choreographer calls them. Sorry.
When the performers splash, spin, dance, and kick the water on for spectacular performance on a flood stage or video.