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
River Awbeg rises about two miles north of Liscarroll and flows south and then north and west under Annagh Bridge to join the first branch at Scart Bridge. From there, the river flows south through Buttevant and east through Doneraile, turns south near Shanballymore and through Castletownroche to enter the Blackwater at Poulcormac near Bridgetown Abbey. North of Buttevant the river flows through flat agricultural land, while south of Buttevant the river generally flows through a narrow, steep-sided valley with wooded sides. For the most part the river flows over Carboniferous limestone. The river supports a range of plant species including dropwort,