Some materials where very simple, because I knew the detail was not going to be seen, the objects where just to far away from the camera. Because of this I had to make a strong water material.
I first started to use Houdini Ocean plugin which is free, but the result was a very agitated water, and so I just went for the simple bump map and it turned out to be just enough. To replicate the bottom of the lake, I tryed to find a texture of ocean deep with some sea plants but they are hard to find and I didn’t have time to create one on my own. So I decided to add a simple layer of pebble stones (in 2D was good enough) and you may not see them at first time but they add a nice detail in the end.