The Nonnenmattweiher is a

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 ...

that has been impounded by an embankment in the Southern Black Forest in

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 ...

. Together with the surrounding area it forms a

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geologic ...

of the same name in the High Black Forest in the state of

Baden-Württemberg Baden-Württemberg ( ; ), commonly shortened to BW or BaWü, is a states of Germany, German state () in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million i ...

Name

The name of the lake goes back to the formerly common word for the mast intended as feed for cattle – the so-called ''Nonnen'' or ''Nunnen''. It used to be pastured on the meadows in the bottom of the

cirque A (; from the Latin word ) is an amphitheatre-like valley formed by Glacier#Erosion, glacial erosion. Alternative names for this landform are corrie (from , meaning a pot or cauldron) and ; ). A cirque may also be a similarly shaped landform a ...

. Later people presumed that the name came from a

nunnery A convent is an enclosed community of monks, nuns, friars or religious sisters. Alternatively, ''convent'' means the building used by the community. The term is particularly used in the Catholic Church, Lutheran churches, and the Anglican Comm ...

(''Nonnenkloster'') which, according to

legend A legend is a genre of folklore that consists of a narrative featuring human actions, believed or perceived to have taken place in human history. Narratives in this genre may demonstrate human values, and possess certain qualities that give the ...

, sank into the lake as a result of God’s judgement.

Geography

The pond and the nature reserve lie near Heubronn, a village in the parish of Neuenweg (in the municipality of Kleines Wiesental), in the Southern Black Forest in

. Other nearby villages are Badenweiler and Münstertal. The lake lies on the eastern slopes of the Köhlgarten massif at about and is almost 325 metres long, 200 metres wide and up to 7 metres deep. (3.7 ha) The lake – excluding the large island in the south – has an area of 3.1 ha and is crossed by the ''Weiherbach'' which rises on the '' Heubronner Hang'' to the west and heads east, draining via the (Heubronner) ''Klemmbach'', the ''Belchenwiese'' and the ''Kleine Wiese'' into the Wiese.

Development history

The Nonnenmattweiher was originally formed as a

lake by a

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

during the

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

, but silted up in the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...

and became part of an area of raised bog and boggy pasture. It was impounded as a

millpond A mill pond (or millpond) is a body of water used as a reservoir for a water-powered mill. Description Mill ponds were often created through the construction of a mill dam or weir (and mill stream) across a waterway. In many places, the co ...

for mills further down the valley in 1758, but was intended to support the breeding of trout and carp. But when the lake was dammed, the flooded bog tore away and floated (as a result of the formation of pockets of gas due to fermentation processes in the bog structure), and fish breeding was impractical. On 1 March 1922 the rain-sodden bank could no longer resist the water pressure and the burst, destroying the riverbanks as far as the valley of the Little Wiese. The lake basin dried out until the reconstruction of the embankment in the early 1930s. In early June 1934 the inauguration of the new reservoir which was 2 metres higher than before. The bog floated up to the surface again and covered an even greater area than before. It still forms a floating island of peat, like that of the Huzenbacher See in the Northern Black Forest and the Kleiner Arbersee in the

Bohemian Forest The Bohemian Forest, known in Czech as () and in German as , is a low mountain range in Central Europe. Geographically, the mountains extend from Plzeň Region and the South Bohemian Region in the Czech Republic to Austria and Bavaria in Germ ...

. In 2004 the area hit the headlines when a number of environmentalists complained that tree felling had significantly changed the character of the cirque. In 2007 more tree felling and other incursions of the nature reserve took place.

Protected areas

Nonnenmattweiher in Neuenweg-Heubronn 34

Nature reserve

By order of the Regierungspräsidium Freiburg dated 31 July 1987 the Nonnenmattweiher was declared a

(Protected Area Number 3.161) with an area of 70.8 hectares. It is classed as

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

Category IV. The CDDA Code is 164836 and corresponds with the WDPA ID. The conservation aim§ 3 Schutzzweck
ordinance by the Regierungspräsidium of Freiburg dated 31 July 1987, retrieved 25 November 2013 is the preservation of the region as an especially beautifully formed cirque with high rock faces, the Nonnenmattweiher as a tarn with its

moraine A moraine is any accumulation of unconsolidated debris (regolith and Rock (geology), rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a gla ...

banks in front as a habitat for numerous rare and endangered animal and plant species.

Protected areas

The Nonnenmattweiher had been declared a

protected area Protected areas or conservation areas are locations which receive protection because of their recognized natural or cultural values. Protected areas are those areas in which human presence or the exploitation of natural resources (e.g. firewood ...

as early as 20 January 1941. After designating the nature reserve, a small area of around 2.8 hectares is still a protected area.

Vegetation

Around and in the lake are numerous rare plants. One rarity is the floating peat island that has

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 ...

and transitional bog vegetation. The island is out of bounds. About half the lake is bordered by a barrier of floating logs enabling the rest to be used as a bathing lake.

Literature

* * Geographisch-kartographisches Institut Meyer (1989): ''Südschwarzwald'' (Meyers Naturführer). Meyers Lexikonverlag, Mannheim, * Kurt Ückert: ''Der Nonnenmattweiher - zur Geschichte eines kleinen Sees'', Schopfheim 1989. * Alfred Drexlin: ''Der Nonnenmattweiher bei Heubronn''. In: Der Schwarzwald, Band 1978, S. 152-153

External links

*
The Nonnenmattweiher and surrounding area
at:
Nonnenmattweiher nature reserve

References

* Seefläche nach dem Layer ''Stehende Gewässer'' des Online-Kartenservers der LUBW. Siehe bei den → Weblinks. {{Authority control Lörrach (district) Nature reserves in Baden-Württemberg IUCN Category IV Cirques of Europe Lakes of Baden-Württemberg Protected areas of Germany Tarns of the Black Forest

Name

Geography

Development history

Protected areas

Nature reserve

Protected areas

Vegetation

See also

Literature

External links

References