Wipped this up. . .maybe it'll help. . . it's on the same line as the link with a little more info. 1. create a terrain 2. in the terrain editor you can raise and lower the landform as you please. 3. duplicate the terrain and scale it down vertically so it's inside of the original (it cannot be seen at this time). With the duplicate still selected, change the material to a water texture. In my sample I didn't use a water texture but a rock texture named 'marble, blue and white". You can adjust the fuzziness, transparency and other qualities in the material editor. 4. select the original terrain . . . .and in the terrain editor lower the gray level and the falls will now show through!

This is a rough sample. You can fine tone this procedure to your liking. : )