@mintymile - Thanks for the lovely comment! :) The falls do not form part of a dam system, luckily! In fact, the river in question is the 'Orange River' - one of our major river systems. It starts up in the Lesotho highlands and traverses westwards towards the coast of Alexander Bay, where it drains into the ocean. The Orange River also forms the natural border between Namibia and South Africa. Hope that helps! :)