Vorderrhein

The Vorderrhein (English: Anterior Rhine; in the local Sursilvan language: Rein Anteriur) is one of the two sources of the Rhine. Its catchment area of 1,512 square kilometres (584 square miles) is located predominantly in the Canton of Graubünden (Switzerland). The Vorderrhein is about 76 kilometres (47 mi) long, thus more than 5% longer than the Hinterrhein (each measured to the farthest source). The Vorderrhein, however, has an average water flow of 53.8 m3/s (1,900 cu ft/s), which is less than the flow of the Hinterrhein. According to the Atlas of Switzerland of the Swiss Federal Office of Topography, the source of the Vorderrhein – and the Rhine –is located to north of the Rein da Tuma and Lake Toma.