The Riet flows about 300 km from the vicinity of the eastern Free State town of Smithfield and has a confluence with the Vaal River upstream from the Northern Cape town of Douglas.Morris, D. 2002. Driekopseiland and 'the rain's magic power': landscape and history in a new interpretation of a Northern Cape rock engraving site. MA dissertation, Dept Anthropology and Sociology, University of the Western Cape It flows through the Kalkfontein Dam.
