The Fish River (Visrivier in Afrikaans, Fischfluss in German) is a river in Namibia. It is 650 km long, flowing from the Naukluft Mountains 150 km to the Hardap Dam near Mariental. From there the flow is entirely blocked, all further flow downstream coming from tributaries downstream from the dam. The flow of the river is seasonal; in winter the river can dry up completely.