A water_lod_control is Necessary, it makes the water lower detail when you are far away and can't really see it, reducing the polygons and making your FPS better. I guess it isn't really used for cosmetic purposes but you really just need it when you use water. As for the actual water itself, like I said look for textures that are suited to your needs, there are alot of textures. If you map for DOD Source, there is a REALLY cool water texture, called "nature/water_anzio001_cheap." But you probably don't map on DOD Source. I have noticed that some waters that say "cheap" look really cool. Just keep looking.