What are the rules for a long fall into water? [duplicate]

Normally when a player falls they take 1d6 bludgeoning damage when they hit the ground per 10 foot they fall.

Are there any RAW for a player hitting water? At what height does hitting water in DnD become dangerous. In reality if you hit water from high enough it is the equivalent of hitting concrete and a I imagine from even a safe hight a player that dives badly may hurt themselves?