Climate change, heat and drought have consequences for public water suppliers. Bottlenecks are still the exception. From the point of view of the industry, investments are necessary to ensure that this remains the case.
According to the Deutsche Verein des Gas- und Wasserfaches e. V. (DVGW). And it was way too dry. 2022 will thus follow the dry period of recent years. So what can be done to ensure that the supply of drinking water in Germany remains secure? So that bottlenecks or restrictions remain the exception? The DVGW’s short answer: invest.
For example in the “conversion” of a forest – like in Ferch, southwest of Brandenburg’s capital Potsdam. Young copper beeches, silver birches and Douglas firs, a type of pine, grow there. A new mixed forest of coniferous and deciduous trees is being created, old pine trees have been felled for this purpose.
Forest conversion benefits groundwater
Energie und Wasser Potsdam GmbH (EWP) started this ecological forest conversion in 2020 in order to gain more groundwater. Softwoods like pine are evergreen and need water all year round. Deciduous trees, on the other hand, mainly in the summer months. Studies have shown that the amount of seepage water under mixed forests is significantly higher than under coniferous trees. That could bring about ten percent more groundwater. The EWP has therefore invested almost one million euros in the conversion of the forest and in new wells.
The EWP supplies around 195,000 people in Potsdam and neighboring towns with drinking water. The supply is sufficient at the moment. However, the demand for drinking water is expected to increase – due to the high temperatures, the drought and the growing population in the Potsdam metropolitan area.
Still is drinking water supply secure
The DVGW also sees an increasing demand for drinking water. The supply situation is still secure. This was the result of a survey among the member companies. Only one percent experienced a power outage. At nine percent, it was temporarily restricted, for example for watering the home garden.
90 percent of the water companies surveyed stated that they could have guaranteed the supply of drinking water without restrictions. However: Almost a fifth of the water suppliers surveyed (19 percent) experienced bottlenecks in water resources. For example, because wells or springs temporarily dried up or dams were not sufficiently filled.
Berlin is planning new fountains
“But it is also clear that more measures are needed at different levels to make the water supply fit for the future,” says DVGW board member Wolf Merkel. New extraction areas, new dams, underground water reservoirs or the expansion of long-distance pipelines and interconnected systems between different water suppliers are needed.
The Berliner Wasserbetriebe (BWB) want to invest around six billion euros by the end of 2030, among other things in almost 130 new wells, in the maintenance of the pipeline system and above all in even better sewage treatment plants.
One circular economy for the water
Because the capital does not depend solely on rainfall for drinking water production. Treated, i.e. cleaned, wastewater already accounts for up to 20 percent of Berlin’s drinking water supply. The treated wastewater is fed back into the city’s river, canal and lake system, from where it seeps through the various layers of soil back into the groundwater reserves. “Circular economy,” says BWB board member Christoph Donner.
The BWB supplies the more than 3.8 million inhabitants of the capital with about 215 million cubic meters of drinking water per year. And in principle, the supply situation is considered to be robust: Berlin benefits from the Havel-Spree river system and the Warsaw-Berlin-Moscow glacial valley, which generally ensures higher groundwater levels.
call for thrift
But Berlin is also feeling the effects of the ongoing drought. In 2022, there was only 68 percent of the average rainfall. The result: a groundwater level that has dropped by up to 75 centimeters, says Donner. Like the umbrella organization DVGW, he therefore calls for saving water.
And association board member Merkel also asks: “Does it always have to be drinking water for certain uses, for example for the increasing demand from industry or agriculture?” The association advocates using other water qualities here or reusing water.