World Water Day: Interview with Holger Schüttrumpf

  Copyright: © Peter Winandy

Germany is one of the regions of the world that has lost the most water in recent years. As today is World Water Day, we asked Professor Holger Schüttrumpf from the RWTH Institute of Hydraulic Engineering and Water Resources Management how this could have happened.

RWTH: Professor Schüttrumpf, will water soon have to be rationed in our country?

Schüttrumpf: No, Germany is still a country with a lot of water. For decades, we have even observed an increase in precipitation. Unfortunately, this is very unevenly distributed, which means that it often does not rain at all for a long time and then it rains a lot in just a few days. Last year's flood disaster was partly a consequence of this uneven distribution. In addition, we have had rather wet winters and dry summers for many years - in summer, some of the water evaporates before it can retreat into the ground. Increasing precipitation also does not result in a large increase in groundwater reserves, because a lot of water often runs off without being able to seep away. So it can be said that Germany has lost groundwater as a local result of climate change.

RWTH: What consequences can this have?

Schüttrumpf: Wherever the water supply depends on the groundwater level, problems could arise - whether for agriculture, industry or the water supply for people. In Aachen, we get most of our water from the large reservoirs - which, by the way, are currently well filled. With just over 800 millimeters of annual precipitation per square meter in Aachen, that's not going to change anytime soon. But overall, we humans will have to adjust to greater variability in precipitation and a decrease in the total amount of water available. When it comes to water, we distinguish between nature's use - that is, what plants and animals need - and anthropogenic use. This includes agriculture and industry, but also humans as individuals. On average, a German consumes 122 liters of water a day - in North Rhine-Westphalia, the figure is as high as 133. 40 percent of this is used for personal hygiene, 30 percent for flushing the toilet, 20 percent for washing machines and 5 percent for eating and drinking. The latter is the equivalent of about seven liters, of which two to three liters are drunk and the rest used to prepare food.

RWTH: What can we do about the water shortage?

Schüttrumpf: Of course, individuals can still try to save water. In the last 20 years, this has already reduced average consumption in Germany from almost 150 to 122 liters per person per day. But we need to reduce our water footprint overall - and that includes not only personal water needs, but of course also the water required for industry and agriculture. Many products we buy require a lot of water in the manufacturing process, such as clothing. But the best way to combat the water shortage would be for Mother Nature to come to our aid - with a nice, long downpour of rain.