Cities hardly prepared: risk of heavy rain

Heavy rain and flooding could become an ever greater problem for Germany in the coming years. But many cities and municipalities are insufficiently prepared.

Federal Environment Minister Steffi Lemke presented the national water strategy just last week. For the first time, Germany is working on a plan that is intended to keep an eye on the dangers of too much or too little water. “We have to prepare for the changes in the climate crisis and adapt to the fact that we want to protect ourselves and we have to protect ourselves against flood events and heavy rain,” said the Green politician.

Heavy rain is clearly defined. According to the German Weather Service, between 15 and 40 liters of water fall per hour per square meter in heavy rain. If this happens in a narrowly defined or heavily built-up area, severe flooding can occur ARD-Weather expert Sven Plöger. “If thunderstorms stop, don’t move on, don’t distribute their rain – it’s like a broken lawn sprinkler.” All precipitation then falls on the same spot.

It’s often a matter of minutes

“Water-sensitive urban development” is what it means when cities and municipalities think ahead with construction measures against sudden flooding caused by heavy rain. Because they don’t announce themselves for long, it’s often a matter of minutes. It is therefore about measures that take effect immediately without preparation. But many people are still unaware of the problem, says Professor Theo Schmitt from the Department of Civil Engineering at Kaiserslautern University of Technology. It is therefore necessary to create awareness of these risks.

And that applies not only to individual citizens, but also to those responsible for urban development. Since 2008, municipalities have been called upon to carry out risk assessments in order to find out where in a municipality heavy rain could be dangerous. But in 2022, almost half of the municipalities had not yet complied.

There are also positive examples

Jens Hasse finds this quite understandable. He works at the German Institute for Urban Studies and advises the federal, state and local governments on the issue of adaptation to climate change. “You have to commission engineering offices, and that costs money that the local authorities often don’t have. You can imagine that a small community with 20 or 30 employees cannot process a topic in the same way that a big city or a district administration could.”

There are a few positive examples: Karlsruhe has created multifunctional areas in residential areas. When the weather is nice, they function as a water playground, and when it rains heavily, the retention basins absorb water. Other cities are experimenting with new types of manhole covers designed to avoid flooding the streets.

And what happens at the top? Federal Environment Minister Lemke is flying to New York this week for the UN water conference. Because where the community looks to the federal government, Germany looks to the United Nations. Only together will we be able to achieve something against the threats of climate change.