According to a study, the drinking water supply in the greater Berlin area and along the Spree is threatened with major bottlenecks. In the dry summer months, the river could locally carry up to 75 percent less water if far less groundwater is pumped into the river when lignite mining in Lusatia ends. This shows a study published on Monday by the Federal Environment Agency.

Authorities chief Dirk Messner warned: “In the worst scenario, water could become severely scarce in Berlin and Brandenburg if resolute countermeasures are not taken. The states of Brandenburg, Berlin and Saxony are facing corresponding challenges.”

The background to the problem is that the water discharge in the Spree was artificially increased for more than a century due to mining in Lusatia: groundwater was pumped out for coal mining and discharged there. A good half of the water that the river carries near Cottbus today comes from pumped groundwater. In hot summers, the proportion increases to 75 percent.

The study now proposes, among other things, upgrading dams and water reservoirs and expanding existing lakes as water reservoirs. The federal states should also explore together how water from other regions can be pumped into the Spree through new pipe systems in a way that is as nature-friendly as possible.

It was also said that households, industry and agriculture should also save more water. According to the UBA, one option would also be to continue pumping the groundwater out of the opencast mines for the time being and to direct it into the Spree after it has been cleaned.

Messner said the impending water shortage was no reason to abandon the coal phase-out: “Climate change is the biggest problem we are dealing with. It is already creating droughts and extreme weather. Coal mining has been harmful to the environment for decades. “

The Green League environmental network called for the obligations of the opencast mine operator LEAG to not be ignored. “The company has to bear a proportion of the costs that is fair to the user, otherwise the state threatens to give the fossil fuel corporations billions again,” explained René Schuster, the association’s lignite expert.

According to the study, the lack of water affects, among other things, the supply of raw water for Berlin’s largest drinking water plant in Friedrichshagen. The dilution of the treated Berlin wastewater with Spree water – about 220 million cubic meters per year – is becoming increasingly problematic. At the same time, an additional six billion cubic meters of water will be needed in the coming decades to fill up the remaining opencast mines so that they do not become unstable.