@combatwombat in the video to the left of the falls is one of those areas where the water is allowed to run behind the boulders making the land disapeer into the waters edge breaking up the chain of pearls as it is called . Though I did not use round rocks as edging rocks placed end to end all the long way always looks man made turn a boulder now and then sticking in toward the pond or out place a stump between boulders makes for a very pleasing look and feel of it being natural.