Back from 2013.
My job was compositing and creating simple particle systems for additional rain.
There was a lot of tracking, retiming and warping of the recorded water elements involved. Funny thing is I ended up using a lot of sea and waves footage from my not-so-great holiday in Spain (I usually record stuff when I see I could use it at work - even on holiday ;) ).
The whirlpool was simulated and rendered in Houdini by Piotr Białousz.