Red alert: Lübeck lakes threatened – the water crisis is coming!

Red alert: Lübeck lakes threatened – the water crisis is coming!

In Lübeck, it is no secret that water levels in some groundwater-fed lakes have been a serious issue since the turn of the millennium. While the Pinnsee, Garrensee, Oldenburger See and the Wakenitz are suffering from falling water levels, other bodies of water are showing no changes. Such developments raise questions about changes in the groundwater balance, particularly with regard to the sustainable extraction of groundwater. Professor Christoph Külls from the Lübeck University of Technology will present his research results in a lecture on October 29, 2025 from 6 to 7:30 p.m. There will also be an open discussion on this occasion, followed by a networking segment and a small snack. Anyone interested can register at Veranstaltung.bau@th-luebeck.de. Admission to this event is free, which increases the chance to exchange ideas and find out more. HL live reports about this event.

Urban areas are also causing increased problems. Cities often face drainage problems during heavy rainfall. High amounts of precipitation often cannot be adequately absorbed by the ground, resulting in flash floods, rising water levels and even flooding. Sealing areas through construction, asphalting and other measures does not exactly contribute to the solution. Rather, this means that rainwater cannot seep into the ground and is instead drained into combined sewer systems, which are often not designed to handle large amounts of water. The BUND emphasizes, these overflows often lead to untreated contaminated wastewater entering bodies of water, which not only damages ecosystems but also endangers the health of local residents. In the summer period, the declining water quality can even lead to bathing bans, for example due to the emergence of cyanobacteria.

The need for a sponge city

So we are faced with a challenge: a functioning landscape water balance is crucial for healthy ecosystems and water availability. According to current estimates, only 9% of rivers and lakes in Germany are in good ecological condition, which makes it clear that there is a need for action here. The Federal Environment Agency emphasizes that the pressure on soils and water is increasing due to more frequent dry periods and heavy rain events. A shift towards climate-adapted “sponge landscapes” could be a solution. These landscapes would be able to better retain and store water.

A healthy water balance buffers climatic extremes and supports biodiversity. Unfortunately, historical changes, such as the straightening of rivers and the sealing of land, have led to lower groundwater levels and drier soils. Climate change is compounding these challenges and the need for sustainable action is becoming increasingly clear. Renaturation projects, such as the relocation of dikes, could provide valuable services here by creating flood areas and improving habitats for various species. In addition, municipalities should be supported with regard to adapted land management.

In summary, it should be noted that the challenges in the water balance not only affect Lübeck, but also numerous regions in Germany. It is up to us to take action and set the course for a climate-adapted future. Whether through the creation of more green spaces in cities or the renaturation of rivers, the coming years offer the opportunity to focus our attention on a sustainable and livable environment.