Sandbags line properties, boards secure entrances, mattresses and other things lie on the roadside that the water has made unusable. A few days after floods of lightning quickly made their way from the maize field above the neat detached houses, especially into basements and garages, tidying up and cleaning is still the order of the day. And hedge. The next rain is sure to come. In the Fliederstraße in Karlsbad-Langensteinbach (Karlsruhe district), many have taken vacation to secure their belongings. Some stoically shovel sand into sacks, others clean the gully in front of the house, and one woman takes her frustration out on Mayor Jens Timm. “Your nerves are on edge,” he says.
Since the middle of June, unusual heavy rain has hit the 16,000-inhabitant community three times. In some districts the water was meters high. Land was also under in the town hall and in schools. The newly renovated Catholic kindergarten can no longer be used for the time being. The fire brigade recorded around 250 missions. How many people cleared their houses of mud and water without help is not known. The extent of the damage is still uncertain.
Thunderstorms, storms and floods
Karlovy Vary is not an isolated case. Kraichtal (Karlsruhe district), Dußlingen (Tübingen district) or Stuttgart: In many places there have been violent storms in recent weeks. The SV Sparkassenversicherung anticipates damage of up to 200 million euros.
Thunderstorms, storms and floods are a result of climate change, the Baden-Württemberg Environment Minister Thekla Walker (Greens) is convinced. And she warns: municipalities must prepare for extreme weather conditions. But how? “Heavy rain events are very fragmented, and the water falls from the sky in a very short time,” says Susanne Nusser, Vice General Manager of the Baden-Württemberg City Council. And in contrast to flooding in rivers, there is hardly any advance warning.
Anything in the way
This was also shown by the example of Braunsbach (Schwäbisch Hall district), where five years ago a trickle turned into a torrential flash flood. Gigantic amounts of water swept away everything that stood in the way: parts of houses, cars and trees, 50,000 tons of rubble.
“The key question is: How can we, structurally and through precautionary measures, prevent water from collecting in unfavorable places?”, Says Nusser. In addition to efficient street drainage, sufficiently large sewers and the support of endangered slopes, they also include functioning warning chains.
“Sewer systems and drainage systems are not dimensioned for such events”
From risk analyzes and dam construction to the diversion of watercourses – some of the 1,101 cities and municipalities in the state have already been active: According to the Ministry of the Environment, 51 municipal heavy rain concepts have been completed, funds have been approved for 163, and further programs have been applied for.
“If you had taken climate change and the associated extreme weather phenomena seriously earlier, you could have started taking action earlier,” says Ralf Roos, head of the Institute for Roads and Railways at the Karlsruhe Institute of Technology. The KIT professor warns: “The sewer systems in the cities and the drainage facilities outside of the city are not dimensioned for such heavy rain events because they did not exist earlier in this intensity and frequency.” Just expand everything a little, not enough. “We need a new tax base and then have to adapt drainage systems.”