River source

From the headwaters of a stream or river is when can not be clearly locate the source of the water or - for example, in the corresponding geological underground - extends over a larger area.

This is often in the high Alpine valleys such as the Engadine ( upper reaches of the Inn) is the case. About Graubünden for the front and the back of the Rhine - - Sometimes even an entire region as the source area is described.

While such source areas - often caused by water astonished sediments under permeable surface - usually have a rather two-dimensional expansion, the headwaters of many karst springs can be described as clearly three-dimensional.

Numerous examples can be found in the Karst of the Balkan Peninsula, in Slovenia, but also in the Limestone Alps. The Upper Austrian Dead Mountains knows underground source areas that are dozens of square kilometers in size, before they fed river finally comes to light. When Pießling origin, one of the strongest karst springs of Austria to Spital am Pyhrn, the water-rich stream flows only after 7-8 km in the Teichl and later into the river Steyr.

Other extensive source areas can be moorland, which then frequently - such as the Schwenninger Moss, source of the Neckar - be SPAs. Protection Worthy are often larger areas where the supply can rely on no drinking water engräumig localized sources.