Concordiasee

Flooded opencast mine

The Concordiasee (Latin concordia " concord " ) is the largest artificial lake in the Harz mountains in Saxony- Anhalt. It is located about eight kilometers northwest of Aschersleben, bordering belonging to the city Zealand Nachterstedt districts in the south and in the north Schadeleben.

History

The name of the lake is derived from the former brown coal mine Concordia. By 1996 initiated flooding of former opencast Nachterstedt, the largest remaining hole in the former coal mining area in Salzlandkreis, creating a multi-use lake as the center of a developing mining landscape, leisure landscape Harzer Zealand. In the summer of 2002, the Concordiasee reached a water area of ​​about 300 hectares. With an opening ceremony on 17 August 2002, the lake was officially released for water tourism. Since May 25, 2005 regularly frequented in the season, a 250 people comprehensive passenger ship, the MS Zealand pearl on it. In summer 2009, the water area covered 350 ha It was the biggest tourist usable waters between Magdeburg and Braunschweig and Kassel and Halle ( Saale). The maximum water level should be reached in 2015 at about 103 meters above sea level and a water area of ​​650 hectares. The maximum depth of the lake will then be 61 meters.

Accident and its cause

On July 18, 2009 4:40 clock in the area rushed to the place Nachterstedt a 350 by 150 meter wide strip of land in the resulting lake. Here, a semi-detached house, part of a further double house as well as a section of road with viewpoint and information kiosk were torn into the deep; the mass of earth slid down an estimated 1.4 million cubic meters. Three people died and 41 other people of the settlement Am Ring homeless.

The tidal wave pushed on the opposite shore, the excursion boat Zealand pearl onto the bank and the water level of the lake rose Concordia, thereby enlarged the lake surface. The entire lake area with its immediate environment has been cordoned off and declared a disaster area for a few days because more Erdabbrüche threatened.

The site has slid down was part of a mining dump from the period before 1926, which was released in the 1930s for construction of homes. It was initially suspected that non-filled stretches of the second half of the 19th century, when coal was more important in the civil engineering, could be the cause of the landslide. Likely to be the cause at first seemed a reduction flow. 1950 and 1959 in the mine caused already by setting flow landslides had occurred, where in 1959 a worker was killed.

Three months after the landslide has confirmed evidence of a small earthquake as the cause of the accident, the Lusatian and Central German Mining Administration Company ( LMBV ). An Institute of the University of Leipzig has registered a tremor of 1.0 on the Richter scale with six minutes left input of the first emergency call in Nachterstedt. This seismic event was the beginning of the landslide. The center of the quake was located outside of the mine. In an interview with the Central German newspaper said Mahmut Kuyumcu, Managing Director of LMBV that registered at 4:42 clock quake represents the beginning of a long chain of causes that led to the accident. The exact location of the quake could not be located, but lies outside the actual open pit, possibly in the area of the former lignite civil engineering. An initially adopted pure translation flow he excludes, as the drip line is very stable and the expected reduction in a flow season break has failed. Due to the high stability of the escarpment, the hopes of the inhabitants of the locked settlement to be allowed to enter once their homes are increasing. The earth tremor has been known longer. The State Mining Authority of Saxony-Anhalt explained that this measurement is probably nothing more than documenting the collapse of more than two million cubic meters of earth, but not a seismic event.

Even two years after the quake, it was not clear why the landslide took place. In the first half of 2011, extensive drilling and cone penetration tests were carried out to investigate the accident and the lake to be able to open it to tourism again. Still, the lake is blocked because several riparian areas could slip. 2012, the results of tests are available and at least partial areas are released.

Based on the investigation of the Concordia lake was decided in 2013, which still must remain closed for another two years the lake. Plans call for a bathing and the release of the lake for the season 2015.