06/01/2024 It has rained a lot in large parts of Germany in the past few weeks. Many rivers have overflowed their banks, numerous areas are flooded, dikes are giving way and the water is threatening towns and cities. Countless rescue workers and helpers are fighting to limit the damage.
Our use of water is a key reason for the floods: water management today is designed to drain rainwater from the landscape quickly and in a controlled manner. That's why it is crisscrossed with a dense drainage network of ditches, underground drainage pipes, receiving waters, pumping stations, etc. Straightening watercourses also contributes to the water flowing away more quickly. However, when there is high rainfall, this drainage system is overloaded. The water cannot be drained away quickly enough and flooding is the result.
Modeling shows that higher winter precipitation and more heavy rain events are to be expected in the future due to climate change. It therefore becomes even more important to make flood protection safer for the future. Simply thinking about more stable and higher dikes is not enough. Rather, retention areas should be given much greater consideration because they have great importance and great potential for flood protection. Peatlands play a prominent role here. When drained, they can exacerbate flood situations if their peat is degraded and compacted. Wet peatlands, on the other hand, can absorb and store water like a sponge, thus delaying runoff. With a peat formation horizon (so-called acrotelm) in the uppermost decimetres, they are able to “breathe”, so the surface fluctuates depending on the water supply (so-called peat oscillation). Short-term flooding thus does not harm wet peatlands, even if they are used for agricultural purposes in paludiculture. This allows them to buffer flood peaks. This is also why they say “Peatland must be wet!”.