I don’t know much about pond-less features, since I have a pond.


But the gist of a pond-less feature is the the hidden reservoir holds enough water to operate the feature and a little bit more, to account for losses from evaporation and splashes. The reservoir is hidden under a cover, or filled with river rocks, so that the water is hidden before it is recycled back into the feature.
For my pond and marsh I used traditional pond liner material. The thick black rubber stuff. If you are doing a pond-less feature, then you will not have to be concerned about your liner leaching fish killing chemicals into the water. So you could use rubber roofing membrane as your liner. The liner should be wide enough to make the stream bead, and a bit more, so that water doesn’t find its way out of the system. Water will wick up through dirt, so the edging of your water feature should be rock. Since you wont have fish, and if you wont be having any water plants, a bit of chlorine bleach added to the water from time to time will kill off the algae and other stuff growing in the water.
Beyond that, I don’t really know too much more about pond-less features.