As far as I know, there aren't any water parks in the area that are open at night. This proposed theme could be great for a nighttime park.
Can you imagine a giant looming volcano at night with bright glowing lava streams running down the sides? Along with the back-lit beach sand patent and fiber-optic stuff, it could rival a certain alien moon down the street in terms of bioluminescent/phosphorescent goodness.
EDIT: And I might be going totally off the deep end here (no pun intended), but what if they could cultivate and maintain something like these bioluminescent dinoflagellates?!
[video=youtube;uqJbUKEPgXc]https://www.youtube.com/watch?v=uqJbUKEPgXc[/video]