Lake Constance

Lake Constance
Bodensee
satellite image
map
Location Germany, Switzerland, Austria
Primary inflows Rhine
Primary outflows Rhine
Catchment area 11500 km²
Basin countries Germany, Switzerland, Austria,
Max. length 63 km
Max. width 14 km
Surface area 536 km²
Average depth 90 m
Max. depth 254 m
Water volume 55 km³
Residence time 4.3 years
Surface elevation 395 m
Frozen 1795, 1830, 1880 (partial), 1963
Islands Mainau, Reichenau, Lindau
Sections/sub-basins Obersee, Überlinger See; Untersee, Zeller See, Gnadensee
Settlements see list

Lake Constance (German: Bodensee) is a lake on the Rhine at the northern foot of the Alps, and consists of three bodies of water: the Obersee ("upper lake"), the Untersee ("lower lake"), and a connecting stretch of the Rhine, called the Seerhein.

The lake is situated in Germany, Switzerland and Austria near the Alps. Specifically, its shorelines lie in the German federal-states of Bavaria and Baden-Württemberg, the Austrian federal-state of Vorarlberg, and the Swiss cantons of Thurgau and St. Gallen. The Rhine flows into it from the south following the Austro-Swiss frontier. It is approximately located at .

Lake Constance was first mentioned by the Roman geographer Pomponius Mela about AD 43. He noted that the Rhine flows through two lakes, and gave them the Latin names Lacus Venetus (Obersee) and Lacus Acronius (Untersee). Pliny the Elder used the name Lacus Brigantinus, after the Roman city of Brigantium (today Bregenz). The lake is also colloquially known as the Swabian Sea[1] (das schwäbische Meer). The modern name is akend from the nearby town of Bodman.

The freshwater lake sits at 395 m above sea level and is Central Europe's third largest, after Lake Balaton and Lake Geneva. It is 63 km long, and at its widest point, nearly 14 km. It covers approximately 571 km² (208 mi²) of total area.[2] The greatest depth is 252 m in the middle of the eastern part (Obersee). Its volume is approximately 55 km³. The lake has four parts: Obersee (main, 476 km²), Überlinger See (north, 61 km²), Untersee (west, 63 km²), and the Zeller See and Gnadensee (northwest). The regulated Rhine flows into the lake in the southeast, through the Obersee, the city of Konstanz and the Untersee and flows out near Stein am Rhein. Lake Constance provides fresh water to many cities in south Germany.

Lake Constance was formed by the Rhine Glacier during the ice age. The Rhine, the Bregenzer Ache, and the Dornbirner Ache carry sediments from the Alps to the lake, thus gradually decreasing the depth of the lake in the southeast.

The lake was frozen in the years 1077 (?), 1326 (partial), 1378 (partial), 1435, 1465 (partial), 1477 (partial), 1491 (partial?), 1517 (partial), 1571 (partial), 1573, 1600 (partial), 1684, 1695, 1709 (partial), 1795, 1830, 1880 (partial), and 1963.

Approximately 1000 tons of fish were caught by 150 professional fishermen in 2001 which was below the previous ten year average of 1200 tons per year. The Lake Constance trout (Salmo trutta) was almost extinct in the 1980s due to pollution, but thanks to protective measures has made a significant return.

The lake itself is an important drinking water source for southwestern Germany, called Bodenseewasserversorgung ("Lake Constance Water Supply").[3]

Car ferries link Romanshorn, Switzerland to Friedrichshafen, and Konstanz to Meersburg.

Contents

International borders

There is no legally binding agreement as to where the boundaries lie between Switzerland, Germany and Austria where these three countries meet in Lake Constance. While Switzerland holds the view that the border runs through the middle of the lake, Austria is of the opinion that the lake stands in condominium of all the states on its banks. Germany holds no unambiguous opinion. Legal questions pertaining to ship transport and fishing are regulated in separate treaties.

Naturally, disputes arise. One concerns a houseboat which was moored in two states, another concerns the rights to fish in the Bay of Bregenz. In relation to the latter, an Austrian family was of the opinion that it alone had the right to fish in broad portions of the bay. However, this was accepted neither by the Austrian courts nor by the organs and courts of the other states.[4]

Recent floods

Islands in the lake

The three major islands are:

This is a complete list of the islands in Lake Constance, listed from east to west:

Nr. Island Area (m²) Population Municipality Coordinates
1 Galgeninsel peninsula since 19th century - Lindau (Reutin district)
2 Hoy 53 - Lindau (Reutin district)
3 Lindau 680,000 3,000 Lindau (Island district)
4 Wasserburg peninsula since 1720 27 Wasserburg (Island district)
5 Mainau 447,584 185 Konstanz (Litzelstetten district)
6 Dominikanerinsel 18,318 21 Konstanz (Altstadt district)
7 Mittlerer Langbohl 31,254 - Konstanz (Industriegebiet district)
8 Triboldingerbohl 135,570 - Konstanz (Industriegebiet district)
9 Reichenau 4,300,000 3.200 Reichenau (Unterzell|Mittelzell|Oberzell)
10 Liebesinsel 300 - Radolfzell (Mettnau district)
11 Werd 15,854 9 Eschenz (Untereschenz district)
12 Mittleres Werdli 4,000 - Stein am Rhein
13 Unteres Werdli 6,000 - Stein am Rhein
  Lake Constance Islands 5,637,079 6,400 6 municipalities  

Towns and cities at the lake

Lake Constance seen from Spot satellite.
Bodensee Steamboat Hohentwiel.
View from mount Pfänder of Bregenz and the lake (with Lindau in the background).
Reichenau seen from the German shore.
Lake Constance from Lindau
Twilight near Arbon.
The Lower Lake (Untersee).

Austria

Germany

From the entry of the Rhine, on the northern or right shore:

Switzerland

From the entry of the Rhine, on the southern or left shore:

See also

References

  1. ↑ Gordon McLachlan. The Rough Guide to Germany. Rough Guides Ltd. London, 2004. ISBN 1-84353-293-X.
  2. ↑ Image #432, Flying Camera Satellite Images 1999, Lloyd Reeds Map Collection, McMaster University Library.
  3. ↑ "Bodensee-Wasserversorgung", German language Wikipedia.
  4. ↑ David Mark and Barry Smith, et al., Bizarre Shapes: 100 Geographic Monsters.

Literature

External links