Is there a cheat to build pools and fountains on beach lots?

Hmm... As builder myself, I've been thinking. You wouldn't be able to build fountains, but you could sort-of have a pool. In the shallow water, build a square (or whatever shape you want) for the pool. Remove the floor. Hmm, maybe I should try it then post screenshots. Be easier than explaining it in text.
Basically like this:
https://i.imgur.com/7PZpzea.png