How to make low poly water?

I’m creating a game in Unity3D and I’m using blender as my main modeling software, The problem here is that I don’t know how to make a low poly water cube, I’ve seen that a lot of people makes this using a plane, but I need to make a cube, and I can´t find how to make this in blender render or in Unity without A package from Asset Store. It should look like this:

You can subdivide using the " W " shortcut then set the amount to the desired number if needing more than 10 just use " W " again.

Set it to normal and adjust the fractal amount to desired height

Select the edge faces and delete them.

Select the top and bottom edges and bridge edges.

Face select one side at a time on x, y axis and scale them to zero so they end up flat, then select the whole bottom faces of the cube and scale on the z axis to zero.

If you do an edge select and select the whole top outer edge and “ctrl+B” to bevel you can get the rounded edge look like in the image you posted.

All that is left is creating the materials and lighting.