The Dümmer () or officially Dümmer See is a large

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

in southern

Lower Saxony Lower Saxony is a States of Germany, German state (') in Northern Germany, northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' of the Germany, Federal Re ...

(

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

). It has a surface of 13.5 km² and an average depth of one metre. Its elevation is 37 metres. Dümmer is a popular resort for water sports, but also an important

biotope A biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of flora (plants), plants and fauna (animals), animals. ''Biotope'' is almost synonymous with the term habitat (ecology), "habitat", which ...

for water birds and located in a zone especially frequented by

migratory bird Bird migration is a seasonal movement of birds between breeding and wintering grounds that occurs twice a year. It is typically from north to south or from south to north. Migration is inherently risky, due to predation and mortality. Th ...

s. A large section of its shore is protected by nature reserve areas.

Etymology

The word "diummeri" is first attested in 965. „Dümmer“ ist probably derived from "dummerig", meaning moist or shaded, and "Meer“, meaning sea. In northwestern Germany, "Meer" is the traditional term for still waters surrounded by marshes (see: "

Steinhuder Meer Lake Steinhude, , , is a lake in Lower Saxony, Germany located northwest of Hanover. Named after the nearby village of Steinhude, it has an area of about , making it the largest lake of northwestern Germany. At the same time, Lake Steinhude is ...

" and "

Zwischenahner Meer is a lake in Ammerland, Lower Saxony, Germany. It is at an elevation of approximately , and has a surface area of . The town of Bad Zwischenahn is located on the southern end of the lake, Rostrup on the western end, and Dreibergen on the northe ...

"). Possibly, there is also a connection between ''Dümmer'' and the southern dutch word „doom“ ("mist", "broom"). Hermann Friedrich Jellinghaus: ''Die westfälischen Ortsnamen nach ihren Grundwörtern.'' 1847, S. 103. Artikel ''mar, mer''
Digitalisat
.

Location

The Dümmer is located in the Dümmer depression. One and a half miles to the west, the

Damme Hills The Damme Hills are a high, wooded ridge, up to , in the Oldenburg Münsterland in the southern part of the district of Vechta, in western Lower Saxony, Germany. Geography Location The ridge of the Damme Hills, which is about long and on ...

begin to rise, eventually reaching a height of 145 m. Around the lake are

fen A fen is a type of peat-accumulating wetland fed by mineral-rich ground or surface water. It is one of the main types of wetland along with marshes, swamps, and bogs. Bogs and fens, both peat-forming ecosystems, are also known as mires ...

s (''Niedermoore'') and

raised bog Raised bogs, also called ombrotrophic bogs, are acidic, wet habitats that are poor in mineral salts and are home to flora and fauna that can cope with such extreme conditions. Raised bogs, unlike fens, are exclusively fed by precipitation (ombro ...

s (''Hochmoore''). The lake lies in the

Dümmer Nature Park The Dümmer Nature Park () in North Germany is located in the Lower Saxon districts of Diepholz and Vechta and the North Rhine-Westphalian district of Minden-Lübbecke. It is about northeast of Osnabrück and lies between Diepholz and Bohmte, B ...

, which is just under 500 km² in area, and in which the Damme Hills and

Stemweder Berg The Stemweder Berg (also known as the Stemmer Berge)Because it has several rounded summits, it should really be called the ''Stemweder Berge'' i.e. "Stemwede Hills". is a ridge above sea levelHeight according tDeutsche Grundkarte auf geoserver.nr ...

form the central elements of the landscape. The open water of the lake belongs entirely to the district of

Diepholz Diepholz (; Northern Low Saxon: ''Deefholt'') is a town and capital of the district of Diepholz in Lower Saxony, Germany. It is situated on the rivers Hunte and Lohne, approximately 45 km northeast of Osnabrück, and 60 km southwes ...

, but on its western shore the district of

Vechta Vechta (; Northern Low Saxon: ''Vechte'') is the capital and largest city of the Vechta (district), Vechta district in Lower Saxony, Germany. It is home to the University of Vechta. It is known for the 'Stoppelmarkt' fair, which takes place every ...

extends up to the dyke foreland. Near Dümmerlohausen the district boundary comes within a few metres of the shoreline. To the southwest by the mouth of the

River Hunte Hunte () is a long river in north-western Germany (Lower Saxony), a left tributary of the Weser. The Hunte rises in the Wiehen Hills. In the North German Plain it flows through lake Dümmer. It flows generally northwards through the towns Bad ...

a tip of the territory of the district of

Osnabrück Osnabrück (; ; archaic English: ''Osnaburg'') is a city in Lower Saxony in western Germany. It is situated on the river Hase in a valley penned between the Wiehen Hills and the northern tip of the Teutoburg Forest. With a population of 168 ...

advances to within half a kilometre of the lake. Whilst Diepholz district belonged to the

Electorate of Hanover The Electorate of Hanover ( or simply ''Kurhannover'') was an Prince-elector, electorate of the Holy Roman Empire located in northwestern Germany that arose from the Principality of Calenberg. Although formally known as the Electorate of Brun ...

from 1585 (

County of Diepholz The County of Diepholz (West Low German: ''Deefholt''), that was first known as the Lordship of Diepholz, was a territory in the Holy Roman Empire in the Lower Rhenish–Westphalian Circle, Lower-Rhenish-Westphalian Circle. It was ruled by the Nob ...

) and 1582 (

County of Hoya The County of Hoya (German: ''Grafschaft Hoya'') was a state of the Holy Roman Empire, located in the present German state of Lower Saxony. It was centred on the town of Hoya on the middle Weser river, between Bremen Bremen (Low German also ...

), the territory of the district of Vechta belonged for centuries to the Diocese of Münster and only became part of Oldenburg in 1803 after the

German Mediatisation German mediatisation (; ) was the major redistribution and reshaping of territorial holdings that took place between 1802 and 1814 in Germany by means of the subsumption and Secularization (church property), secularisation of a large number of ...

. Hence it counts as part of

Oldenburg Münsterland The Oldenburg Münsterland, otherwise called Oldenburger Münsterland or Oldenburgisches Münsterland, is a region in Lower Saxony, Germany and the administrative area that comprises the Districts of Germany, federal districts of Cloppenburg and ...

Character

The Dümmer is, after the

, the second largest lake in Lower Saxony. With its water surface of 13.5 km ² - the area within the ring dyke including siltation zones is 16 km ² - and maximum water depth of just 1.50 m, it is good for swimming and water sports. The shallow lake with its flat beaches on the western and eastern shore is up to 5 km long from north to south and up to 3.4 km wide from west to east. The lake is crossed by the

, which leaves the lake via several branches, the largest of which is not called the "Hunte" but the Lohne. Other branches are the

Grawiede Grawiede is a river of Lower Saxony, Germany. It is one of the outflows of the lake Dümmer, and it flows into the Hunte near Diepholz. Course The 17 km long Grawiede runs exclusively between the Lower Saxony inland lake Dümmer and the Lower S ...

and the artificial Wätering, the Dorflohne, Schoddenlohne and Ompteda Canal. Only 13 km north of the lake and 3 km north of

all the branches of the Hunte are reunited. The fish-filled lake, which is also a breeding and resting place for birds, has a variety of

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

and

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

, which is why the western and the southern shore of the lake are largely protected.Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz (NLWKN): ''Naturschutzgebiet "Dümmer"''
/ref> Although the lake is only about a metre deep on average, very rich water sources and the Hunte itself ensure that its water level is relatively constant. Previously these headstreams combined with regular heavy rainfall to cause flooding, so that in the 1940s work began to build dykes around the lake. In the period 1941-1945 foreign

forced labour Forced labour, or unfree labour, is any work relation, especially in modern or early modern history, in which people are employed against their will with the threat of destitution, detention, or violence, including death or other forms of ...

was used for this on a large scale. The reclamation and subsequent lack of annual flooding resulted in algae growing in large quantities in the lake and hence depriving most other organisms of oxygen. The low water level was caused by heavy silting, also a result of dyking the lake. With the help of several locks it was possible to control the high water levels artificially without greatly interfering with nature. Nevertheless, the Dümmer suffers from heavy nutrient pollution caused by intensive agriculture. The remains of

New Stone Age The Neolithic or New Stone Age (from Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revolution, a wide- ...

settlements have been found on the shores of the Dümmer.

References

Sources

* Friedrich, Ernst Andreas (1980). ''Naturdenkmale Niedersachsens''. Hanover. * Helbig, Andreas J., Ludwig, Jürgen and Belting, Heinrich (1990). ''Die Vögel des Dümmer-Gebietes. Avifauna eines norddeutschen Flachsees und seiner Umgebung'' (Naturschutz und Landschaftspflege in Niedersachsen 21). Hanover * Klohn, Werner (1992). ''Probleme der Raumgestaltung in der Dümmerniederung'' Vechta * Klohn, Werner (1986). ''Verbreitung, Struktur und Funktion der Kleinstwälder und Gehölze in der Dümmerniederung und ihren Randgebieten'' Vechta * Klugmann, Ulrike and Villwock, Ingeborg (1984). ''Dümmer und Wiehengebirge'' (Naturmagazin "Draußen", Heft 35). Hamburg * Sanden-Guja, Walter (1960). ''Der große Binsensee.'' 2nd expanded edition, Stuttgart * Schmidt, Arno (1955). ''Seelandschaft mit Pocahontas.'' Erzählung. * Seehafer, Klaus (1980). ''Der Dümmer See in Farbe. Ein Reiseführer für Naturfreunde''. Stuttgart

External links

* * {{DEFAULTSORT:Dummer Lakes of Lower Saxony LDummer Vechta (district) Ramsar sites in Germany Important Bird Areas of Germany