For the water scene, I used the following water effects:
Upper river: Woodland Scenics Realistic water and Water Effects.
Lake: Woodland Scenics Deep Water Pour Water, Water Effects and Water Ripples.
Waterfall: Woodland Scenics Water Effects and White Water Highlights, Hobby Lobby quilting batting for the splash.
Lower river: Woodland Scenics E-Z Water, Water Effects and Water Ripples.
Here's how I did it all. Once I had the upper river and lake poured, I measured the width and length of the waterfall. Using the Water Effects, I stippled it onto freezer paper. Once dry, a few brushes of White Water Highlight. Using the Water Effects, I glued the waterfall to the upper river and lake. Once that dried, I used quilting batting. Stretching it out and gluing it down with more Water Effects. To give the water droplets on the batting, I used a stiff brush with Water Ripples on it. Using my finger, I pulled across the bristles to "fling" the Water Ripples onto the batting. Makes a little bit of a mess but works fairly well.
For the upper part of the waterfall, I placed more batting and repeated the droplet procedure like the splash area.
For the splash area in front of the batting, I found mixing a drop or two of White Water Highlights with the Water Effects gave it a more realistic look. Using this mixture, I stippled the area working out towards the middle of the lake. The swells on the lake are done with the Water Ripples. Trick is, once you have the ripples on the water, spray with isopropyl alcohol. This flattens the tops down making a more subtle effect. Use multiple layers to give a better effect with different lighting.
The small falls from the lake into the lower river is with the White Water Highlight-Water Effect mixture. I was experimenting with the E-Z water and I will NEVER use it again. The foam melted even through the plaster coating. Plus, I think it's too yellow. The rest of the river is down with a combination of Water Effect mixture and Ripples. Same angle, take 5 seconds apart but the 2nd pic is with flash to show the water ripples.
Here's another view:
For my first real attempt at a water scene, I have to say, it turned out fairly well. I know what I will and will not do next time. For the water, I will use a two part epoxy. For waterfalls, I'm going to try the technique Lex Parker uses with angel hair and an epoxy resin. You can see it here:
Putting the "white" in the epoxy makes the look very realistic. More so that the batting ever could. I hope this sheds some light in how I did things. Kind of haphazard with the different products but I was experimenting as most of these are the first time I've ever used them.