'We need to return to a landscape that can store water.'

Mr. Borchardt, what is the current situation regarding water in Germany?

The situation can be described in terms of three areas: soil, surface water and groundwater. Much of Germany is experiencing severe soil drought. The topsoil, roughly the top 25 to 30 centimetres, is particularly affected. This is most acutely felt by the agricultural sector because many crops draw their water from this layer. However, the entire soil profile down to a depth of about two metres is similarly affected. At the same time, many major rivers, such as the Elbe, Weser, Rhine and Danube, are carrying very little water. Groundwater levels are also low or very low at many monitoring stations. This is problematic because groundwater reserves replenish slowly. Therefore, we are not only dealing with low water levels in the rivers in the short term, but also with a strained situation in all key areas of the water cycle.

It is often said that Germany is becoming drier. Does that capture the essence of this trend?

Only to some extent. Since 2017/18, we have indeed been experiencing an unusually long drought. However, this change is not clearly evident from average precipitation levels alone. The key factor is that the extremes are becoming more severe. There is increasingly frequent heavy rainfall over a short period of time, concentrated in specific regions, while other areas experience prolonged periods of insufficient rainfall, often accompanied by heatwaves. Therefore, we must focus less on individual dry years and more on these increasing extremes and their duration.

What does this development mean for ecosystems and the economy?

Ecologically, it is the small streams, ponds and lakes that are affected first. When water levels drop in these bodies of water, the water warms up more quickly, oxygen levels decrease and discharged substances are diluted less effectively, as the same amount of pollution is spread out over a smaller volume of water. This creates a critical situation for many species. For a trout, a water temperature of 25 degrees is as stressful as 40 degrees is for us humans in a sweltering city. The numerous organisms in the soil that ensure fertility, water storage and nutrient cycling also suffer when the upper soil layers dry out severely. Floodplains and forests also come under pressure when they lack water for extended periods.

But what about the economic side of things?

The consequences are primarily evident in agriculture, forestry, industry and inland waterway shipping. Some regions are experiencing lower crop yields, while low water levels are disrupting supply chains — for instance, when raw materials or industrial goods can no longer be transported across the Rhine as usual. The extent to which agriculture is affected varies by region and crop. Ultimately, when harvests are scarce, this can lead to higher food prices.

What do we need to do differently with our water in the future?

We need to prepare for the fact that our water balance is no longer as stable as it used to be. In the short term, this means managing floods, low water levels and prolonged droughts more effectively. In the long term, however, we need a paradigm shift — we must find ways to retain more water in both cities and rural areas.

Is it different from the past?

That’s right. We have paved over cities, drained marshes and wetlands, and straightened rivers. The aim was to allow water to drain away as quickly as possible. We need to reverse this trend. The “sponge city” and “sponge landscape” concepts are at the heart of this effort, involving the retention of rainwater, its seepage into the ground, its reuse, and the strengthening of natural reservoirs. We need to return to a landscape that stores water rather than draining it away as quickly as possible.

Many of these solutions are well known. So why are we still making such slow progress?

This is because many stakeholders are affected and have conflicting interests regarding water use. The interests of agriculture, cities, industry and nature conservation are not aligned. However, when it comes to water, progress can only be made through cooperation. After all, a landscape or city that retains more water benefits not only nature, but also makes agriculture and communities more resilient. Added to this is the federal structure. In principle, it makes sense for water management to be primarily the responsibility of the states, given the significant regional differences. At the same time, there is considerable potential for greater cooperation across state lines. Water does not respect administrative boundaries. This is why we need to consider river basins and joint solutions more.

How is the Helmholtz Water Initiative supposed to change that?

Our aim is to bring scientists, the people facing the problems and those responsible for finding solutions closer together. Our goal is to analyse the issues at hand and develop solutions collaboratively. To this end, we have set up three Solution Labs: one focusing on the Elbe River basin, one focusing on urban water systems using Halle and Leipzig as case studies, and one focusing on extreme events in the Rur River basin. It is crucial that research questions are developed in collaboration with the people who will ultimately have to work with the results. At the same time, we aim to make new technologies, such as improved sensor technology, remote sensing, models and digital twins, available for practical use more quickly. Such digital twins can aggregate data from various sources and, in the future, help simulate different courses of action in near real time. The key point is this: This should be an interactive platform and a tool for fact-based, practical decision-making, not a closed shop in the ivory tower of science.

Helmholtz Briefing Wassersecutity