Should I use a blueprint or a C++ script to simulate the flooding of the nile

Hey,
I am new to UE4; I should mention that my game is getting to a point where I can start thinking about scripting the seasonal floods of the nile. am not sure if I should use C++ or a blueprint for the cyclical floods of the nile. Also I was wondering how do I script events for a river the size of the Nile.

thanks

So do I use C++ or blueprints? If no one still answers me I will have to assume that it is a feature I will need to figure out a work around using C++ script.