Drought years take their toll on Berlin's water supply

Berlin's water utilities (Berliner Wasserbetriebe/BWB) have called on the people of Berlin to be more economical in their water consumption in view of the steadily falling groundwater level.

"With the exception of 2021, we have been dealing with a drought situation since 2018," BWB head Christoph Donner said on Wednesday. "Groundwater levels are falling continuously, particularly in the base areas in the northeast and southeast of the city" - by up to 75 centimeters in some areas compared to the long-term average.

"We are a long way from relieving the pressure on our resources"

Last year, drinking water consumption in Berlin hardly increased at all compared to the previous year, with a total of around 215.5 million cubic meters - despite the extreme heat in the summer. Per capita consumption had even fallen by five liters to 113 liters. "But we are a long way from relieving the pressure on our resources," Donner emphasized. Consumers must therefore continue to save more water.

Increasing sealing problematic

The continued increase in sealing of urban areas is also a major problem. "The problem remains the inventory," Donner said. "This is where implementation concepts and resources are lacking to further prepare for the all-important conversion to a sponge city." He said the water company has identified areas totaling about 100 acres that could potentially be unsealed.

Rain as a key resource

In addition, Donner said, the water companies are trying to find out which homeowners are illegally dumping rain into the storm sewer system instead of ensuring that the water can infiltrate. "We don't look at rain as a disposal problem, we look at it as an important resource," he stated.

Greater focus on wastewater cycle

In order to conserve resources, greater attention must also be paid to the wastewater cycle. Last year, the BWB invested around 100 million euros in the purification quality of its own wastewater treatment plants. But the treated wastewater also needs to be put to better use, Donner said. "At the moment, it only knows one way: via the Spree, Havel and Elbe rivers into the North Sea." Wastewater could be used to irrigate green spaces, for example, or one day even to support the drinking water supply.