How to make water flow and take up volume

Hi there,

I'm really new to coding and working with unity, and i was wondering if there was an easy way to make water act like real water on a large scale, it does not need to look good at all, but it has to flow to lower areas and take up volume. If there was a way to do this that would not require unity pro and a great amount of coding that would really help me out. All I really need is for water to move to lowly situated area's like in real life and have volume.

Thanks in advance!