I have had questions lately about pondless watefalls. They are not all that different from regular ponds. First you dig a hole and line it. Put rocks around it. Then you build a waterfall. Fill the pond with water. Put a pump in a cylinder made just for pondless waterfalls. If you looked in my shop at my website, you will notice I do not sell them. There's a good reason for that and here it is:
You have dug the hole, built the waterfall, put the pump in the aforementioned cylinder, put the cylinder with pump in the water. Now you FILL UP THE POND WITH ROCKS. Some of you have already seen ahead far enough to see the problems coming. The water gets dirty. Grass clippings, leaves, dust, dirt from the air, doggy and kiddy toys all find their way into the water and eventually the pump needs to be cleaned. And where is it? Under all those ROCKS!! Hmmmmmm.