The Landscape group I subscribe to had a challenge on waterfalls.I found this swim suit material and it worked very well in making water. At the bottom of the waterfall I used Rainbow Blue Boucle yarn for the foam. Lots of thread painting.
Here is the original picture of the waterfall in Ketchikan, Alaska. We lived there for ten years and hubby has been there for 30 years working for RCA and Alascom long distance communications. The left side is not water but the flash of the camera.