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
White River (Green River tributary) White River (Green River tributary) White River is a river, approximately long, in the U.S. states of Colorado and Utah and is a tributary of the Green River (which flows into the Colorado River). The river rises in two forks in northwestern Colorado in northeastern Garfield County in the Flat Tops Wilderness Area in the White River National Forest. The North Fork rises in Wall Lake, and flows northwest, then southwest. The South Fork rises ten miles south of the north, flows southwest, then northwest, past Spring Cave. The two forks join near Buford in eastern Rio Blanco County, forming