Cottbuser Ostsee

{{expand German|topic=struct|Cottbuser Ostsee|date=September 2021}}

File:19-09-04-Cottbuser-Ostsee-DJIpano 0535.jpg

The Cottbuser Ostsee (Cottbus Eastern Lake; {{langx|dsb|Chóśebuski pódzajtšny jazor}}) is an artificial lake under development on the grounds of the former open-pit lignite mine :de:Tagebau Cottbus Nord near Cottbus, Brandenburg, Germany.

{{Infobox body of water

| name = Cottbus Eastern Lake

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| location = northeast of Cottbus, Brandenburg, Germany

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| coordinates = {{coord|51.786|14.417|type:waterbody_region:DE|display=title}}

| type = flooded former open pit lignite mine

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| part_of = Lusatian Lake District

| inflow = Hammergraben (Spree)

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| date-built = {{Start date|2015|12|23}} end of mining

{{End date|2019|04|12}} start of flooding

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| date-flooded = {{Start date|2019|04|12}} begin of flooding;
{{date|2024-12-23}} target water level reached;

{{End date|2030|12|31}} end of flooding (planned)

| length =

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| area = {{convert|1900|ha}} (planned)

| depth = {{convert|2.5 to 3|m|sigfig=1}} (planned)

| max-depth = {{convert|30|m}} (planned)

| volume = {{convert|150,000,000|m3}} (planned)

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| elevation = {{convert|61.8|m}} above Normalhöhennull (planned)

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| pushpin_map_alt = Location of the lake in Germany.

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Dimensions

When complete, it is to cover a surface area of {{convert|19|km²|abbr=on}}, making it one of the biggest artificial lakes in the country.{{Cite web|url=https://www.leag.de/de/geschaeftsfelder/bergbau/cottbuser-ostsee/|title=Cottbuser Ostsee | Wie ein neuer See entsteht|publisher=LEAG}} At a maximum depth of {{convert|30|m|sigfig=1}} and an average depth of between {{convert|2.5|m}} and {{convert|3|m|sigfig=1}} the lake is to have a total water volume of {{convert|0.150|km3}} once flooding is complete. Until the lake is complete, the biggest artificial lake in Germany by surface area (likewise created by conversion of a former lignite mine) is Geiseltalsee which covers some {{convert|1840|ha}}. However, the water volume of Geiseltalsee is almost three times larger at {{convert|0.423|km3}}. For comparison, Germany's largest lake, Lake Constance, covers {{convert|536|km2}} at a depth of up to {{convert|251|m}} and contains some {{convert|48|km3}} of water. The largest reservoir (i.e. an artificial lake created via a dam) in Germany by surface area is Forggensee in Bavaria with a surface area of {{convert|15.2|km2}} and a maximum water volume of {{convert|0.168|km3}}. However, this lake is reduced to a "rump" of {{convert|3.2|km2}} surface area in winter.

History

The lake covers what used to be the open pit lignite mine "Tagebau Cotbus Nord" which produced a total of {{convert|220|Mt}} of coal during its operation from 1981 to 2015. The last coal was mined in December 2015 and subsequently work began on converting the mine into a lake.

Flooding started in 2019{{Cite web|url=https://www.welt.de/regionales/berlin/article191852725/Geburtsstunde-fuer-groessten-See-Brandenburgs-Tagebau-geflutet.html|title=Geburtsstunde für größten See Brandenburgs: Tagebau geflutet|date=April 12, 2019|via=www.welt.de}}{{Cite web|url=https://cottbuser-ostsee.de/2019/04/15/ostsee-flutung-ist-startschuss-fuer-cottbuser-perspektiven/|title=» OSTSEE-FLUTUNG IST STARTSCHUSS FÜR COTTBUSER PERSPEKTIVEN}} but had to be interrupted several times due to low water levels in the nearby Spree River.{{Cite web|url=https://www.rbb24.de/studiocottbus/panorama/2020/07/brandenburg-ostsee-cottbus-duerre-trockenheit-wasserknappheit.html|title=Dem Cottbuser Ostsee geht das Wasser aus - bevor es da ist|website=www.rbb24.de|access-date=2020-11-20|archive-date=2020-12-26|archive-url=https://web.archive.org/web/20201226102113/https://www.rbb24.de/studiocottbus/panorama/2020/07/brandenburg-ostsee-cottbus-duerre-trockenheit-wasserknappheit.html|url-status=dead}}{{Cite web|url=https://www.rbb24.de/studiocottbus/politik/2020/08/brandenburg-trockenheit-umweltministerium-niedrigwasser-spree.html|title=Umweltminister stuft Lage in Gewässern als "super-ernst" ein|website=www.rbb24.de|access-date=2020-11-20|archive-date=2020-12-04|archive-url=https://web.archive.org/web/20201204232926/https://www.rbb24.de/studiocottbus/politik/2020/08/brandenburg-trockenheit-umweltministerium-niedrigwasser-spree.html|url-status=dead}} The lake is to become part of the Lusatian Lake District, a chain of artificial lakes mostly the result of open-pit lignite mining.

Name

The name – besides referring to the location of the lake to the East of central Cottbus – can be interpreted as a pun on the German name for the Baltic Sea, which is called "Ostsee" in German, the two words only being distinguished by their grammatical gender: "See" meaning "sea" in German is grammatically feminine, whereas "See" meaning "lake" in German is grammatically masculine.

References

Category:Buildings and structures in Spree-Neiße

Category:Artificial lakes of Germany