Editing Rhine (section)

==== Obersee ====
{{Main|Obersee (Lake Constance)}}
The flow of cold, grey mountain water continues for some distance into the lake. The cold water flows near the surface and at first does not mix with the warmer, green waters of Upper Lake. But then, at the so-called ''Rheinbrech'', the Rhine water abruptly falls into the depths because of the greater density of cold water. The flow reappears on the surface at the northern (German) shore of the lake, off the island of [[Lindau (Bodensee)|Lindau]]. The water then follows the northern shore until [[Hagnau am Bodensee]]. A small fraction of the flow is diverted off the island of [[Mainau]] into Lake Überlingen. Most of the water flows via the ''Constance hopper'' into the ''Rheinrinne'' ("Rhine Gutter") and Seerhein. Depending on the water level, this flow of the Rhine water is clearly visible along the entire length of the lake.

The Rhine carries very large amounts of debris into the lake{{snd}}over {{convert|3000000|m3|spell=in|abbr=out|sp=us}} annually.<ref>{{cite web |last1=Bergmeister |first1=U. |last2=Kalt |first2=L. |title=Geschiebeführung |trans-title=Conveyance of bedload |url=http://www.rheinregulierung.at/kms/cms/kms.php?id=21&str_id=22&det_back=1 |publisher=Internationale Rheinregulierung |archive-url=https://web.archive.org/web/20120322191124/http://www.rheinregulierung.at/kms/cms/kms.php?id=21&str_id=22&det_back=1 |archive-date=22 March 2012 |location=Lustenau |language=de |url-status=dead}}</ref> In the mouth region, it is therefore necessary to permanently remove gravel by dredging. The large [[sediment]] loads are partly due to the extensive [[land improvements]] upstream.

Three countries border the Obersee, namely Switzerland in the south, Austria in the southeast and the German states of [[Bavaria]] in the northeast and [[Baden-Württemberg]] in the north and northwest.