Here is a list of some CSS water effects.
CSS Water Effect
Dev: Istiyak Amin
Water droplets on window
Dev: Jérôme Beau
Cup filling with Water CSS Animation
Dev: JustSaas
Simple CSS Waves | Mobile & Full width
Dev: Goodkatz
Wet old CSS rain
Dev: William Paix
Drip Drop Animation (No JS)
Dev: Adib Behjat
Octocat Sprite Swimming in the Ocean with CSS
Dev: Cody Pearce
Pure CSS Rain
Dev: Yannick Brandt
Water wave text animation effect
Dev: Oluwakemi
CSS Water Loading Animation
Dev: Claudia Alphonse
Only CSS: Drop Wave
Dev: Yusuke Nakaya
Sunrise over still lake
Dev: Paulina Hetman
Only CSS: Water Surface #CodePenChallenge
Dev: Yusuke Nakaya
Pure CSS Water Waves [Test]
Dev: Karto
CSS water ripples with blend modes
Dev: Giana