I think it depends on the water type you use, there's an editor tab for water, check what setting your map is using and play around with that, or set it to a different water type that has no waves as default
you can check what water your map is using through the terrain textures tab for your selected terrain
If you mean the ripples in the water, I don't think there's any way around that since water quality, which would include ripple and splash effect, is dictated by your graphics setting. If I'm not mistaken the only way to do this would be to alter your Terrain setting.
I run on a powerful machine so I'm curious as to what this map is called? I'd like to see if it causes problems for me.