Alps rivers such as the Danube have major tributaries flowing into them that originate in the Alps. The Rhône is second to the Nile as a freshwater source to the Mediterranean Sea; the river begins as glacial meltwater, flows into Lake Geneva, and from there to France where one of its uses is to cool nuclear power plants. The Rhine originates in a 30 square kilometre area in Switzerland and represents almost 60 percent of water exported from the country. Tributary valleys, some of which are complicated, channel water to the main valleys which can experience flooding during the snow melt
Powell River (Tennessee River tributary) Powell River (Tennessee River tributary) The Powell River in the United States rises in southwest Virginia and flows into East Tennessee. The river rises in rural Wise County, Virginia, near the Laurel Grove community northwest of Norton and flows for several miles before the confluence with Roaring Fork in the Kent Junction community. From Kent Junction the river flows 187 miles (301 km) and drains approximately 954 square miles (2,471 km) in both Virginia and Tennessee before reaching its confluence with the Clinch River in the Norris Lake reservoir at the site of the now-submerged town of Grantsboro. Powell River