Polder Söllingen / Greffern

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Information board Polder Söllingen / Greffern
Operations center
Acherschöpfwerk at Greffern

The Söllingen / Greffern polder is a retention area to protect against flooding on the Upper Rhine . Located in the districts of Söllingen and Greffern in the municipality of Rheinmünster in the Rastatt district, the polder built between 1998 and 2005 can absorb up to 12 million cubic meters of water over an area of ​​580 hectares.

The construction of the polder was part of the Integrated Rhine Program , which aims to reclaim floodplain areas that were lost in the construction of barrages on the Upper Rhine from 1928 onwards. The loss of floodplain is held responsible for the fact that the expansion cross-section of the Rhine below the Iffezheim barrage is no longer sufficient to divert large floods without the risk of dam breaks. A total of 13 new retention areas are to be created in Baden-Württemberg as part of the Integrated Rhine Program.

The retention area, which consists of four partial polders, is located in an area that is predominantly forested or used for gravel extraction in quarry ponds. More than 100 individual measures were required for the construction: Four extraction structures were built in the Rhine side dam, through which up to 445 cubic meters of Rhine water per second can flow into the polder areas. On the inside, the polder is mainly delimited by existing, reactivated flood dams; New dams were built over a length of four kilometers. Numerous culverts were built to connect the four sub-polders and to keep existing roads and paths passable . Crossings of subordinate paths with bodies of water within the polder were also developed as fords . To avoid excessive groundwater levels inland, three pumping stations were built. A pumping station built near Greffern serves to drain the Acher , the lower reaches of which is used to connect the sub-polders. In the local area of ​​Greffern, which is directly adjacent to the polder, a well gallery was built to lower the groundwater level. The operations center for polder was also built in Greffern. Two educational polder trails were created to inform the population.

A total of 67.5 million euros were invested, 40 percent of which was contributed by the federal government and 20 percent each by the states of Baden-Württemberg, Hesse and Rhineland-Palatinate . At the inauguration in November 2005 it was assumed that the polder can lower the water level at the Karlsruhe-Maxau gauge by up to 40 centimeters, but that it is not possible to influence the water level on the Middle Rhine or at the Cologne gauge .

Polder 'in operation', roads closed

In December 2010, a Rhine flood was used to completely fill the polder for the first time. According to the Karlsruhe regional council , which operates the system, the stress test was successful. It is expected that the polder will have to be flooded every 30 years on average to protect it from flooding. In addition, so-called ecological flooding takes place , in which Rhine water is passed through the waters of the polder on around 190 days per year. On around six days a year, the area of ​​the polder outside the water is also flooded. The ecological flooding should create “ floodplain conditions” so that the forests and communities in the polder area are prepared for complete flooding. Ecological flooding is carried out when the runoff of the Rhine exceeds 1100 cubic meters per second. Up to 49 cubic meters per second flow through the polder. In the event of flooding, higher-lying areas are also closed in order to offer the game undisturbed escape rooms.

The Rastatter Auen Institute of the WWF was involved in the planning of the ecological flooding , and in 1992 it carried out the environmental impact study for the Söllingen / Greffern polder . The head of the Auen Institute, Emil Dister , told the Stuttgarter Zeitung that the Söllingen / Greffern polder was a particularly serious example of the slow implementation of the Integrated Rhine Program, although there was no significant resistance from municipalities or citizens' initiatives. In June 2013, the approval for normal operation of the polder had not yet been granted.

On the Alsatian side of the Rhine, opposite the outlet area of ​​the Söllingen / Greffern polder, is the Moder polder . The polder, which was completed in 1992, can absorb 5.6 million cubic meters of water over an area of ​​240 hectares.

Web links

Commons : Polder Söllingen / Greffern  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Karlsruhe regional council: http://www.rp-karlsruhe.de/servlet/PB/menu/1191993/index.html Measures of the Integrated Rhine Program. (Accessed on June 11, 2011. Link no longer available, August 30, 2015).
  2. ↑ Regional Council Karlsruhe: http://www.rpbwl.de/karlsruhe/abteilung5/ref532/LBG_Oktober2007/projekte/projgrup/soellingen/polder_oeff_arbeit/bw_O_1.htm Polder Söllingen / Greffern - Construction measures: The Acherschöpfwerk with Sielbauwerk (accessed - Bauwerk O. on June 12, 2011. Link no longer available, August 30, 2015).
  3. ↑ Karlsruhe regional council: http://www.rpbwl.de/karlsruhe/abteilung5/ref532/LBG_Oktober2007/projekte/projgrup/soellingen/polder_oeff_arbeit/brunnengalerie.htm Polder Söllingen / Greffern - construction measures: Brunnengalerie, Brunnen 11 - Brunnen 22. (Accessed on June 12, 2011. Link no longer available, August 30, 2015).
  4. ↑ Regional Council Karlsruhe: http://www.rpbwl.de/karlsruhe/abteilung5/ref532/LBG_Oktober2007/projekte/projgrup/soellingen/polder_oeff_arbeit/betriebszentrale_1.htm Polder Söllingen / Greffern - Construction work: Operations center Greffern. (Accessed June 12, 2011. Link no longer available, August 30, 2015).
  5. ↑ An important building block for flood protection. Polder on the Upper Rhine officially put into operation. In: NZZ Online , November 12, 2005 (accessed on March 8, 2019).
  6. ↑ Regional Council Karlsruhe: http://www.rp.baden-wuerttemberg.de/servlet/PB/menu/1321352/index.htm Press release from December 8, 2010. (accessed on June 12, 2011. Link no longer available, 30 . March 2013).
  7. ↑ Karlsruhe Regional Council: http://www.rp.baden-wuerttemberg.de/servlet/PB/menu/1321483/index.htm Press release from December 10, 2010. (accessed on June 12, 2011. Link no longer available, 30 . March 2013).
  8. ^ German Association for Water Management, Sewage and Waste eV (ed.): Flutpolder. DWA, Hennef 2014, ISBN 978-3-942964-81-4 , p. 91.
  9. ↑ Klaus Zintz: Flood protection needs staying power. Stuttgarter Zeitung, June 6, 2013.
  10. ^ German Association for Water Management, Sewage and Waste eV (ed.): Flutpolder. DWA, Hennef 2014, ISBN 978-3-942964-81-4 , p. 92.

Coordinates: 48 ° 46 ′ 54 ″  N , 8 ° 2 ′ 8 ″  E