on its course through the breede river valley, it is joined by the holsloot and smalblaar rivers, from their catchment areas, the du toitskloof and stettyn mountain ranges. the hex river with its catchment area in the hex river mountains also joins the breede river from the north-east. further downstream the slang river and buffeljags river drain the southern slopes of the langeberg mountains before depositing their water in the breede river. near swellendam the river is joined by the riviersonderend, with its catchment area in the mountains surrounding the theewaterskloof dam near villiersdorp.