FloodsGermany: Building Back in Flood-Prone Areas After a Flood

By Natalie Muller and Neil King

Published 15 November 2021

After deadly flash flooding devastated villages in Germany’s Ahr Valley, many residents are hoping to return. But experts say there needs to be a fundamental change in how we build in areas at risk of floods.

Alfred Sebastian surveys the space that used to be his kitchen. There’s no floor, the walls are stripped bare, and the only appliances to be seen are hardware tools and structural drying machines.  

This is what’s left after the catastrophic floods that swept through Dernau, his village in the Ahr Valley, western Germany, in mid-July. 

It all happened so quickly that there was no way to get any of your belongings to safety. We weren’t expecting this amount of water,” he says. 

Known for its picturesque vineyards, the region was left devastated after heavy rainfall turned the usually peaceful Ahr River into a raging torrent.  

Sebastian, who is Dernau’s mayor, was forced to retreat to his home’s upper floors as the water inundated the basement and the ground level. However, since his house was a bit further up the hill, he was better off than most. 

More than 130 people in the valley died and 17,000 others are grappling with damaged homes or lost belongings. In Dernau itself, 400 of the town’s 500 houses are now uninhabitable, according to Sebastian. These residents are now facing questions such as whether to relocate, or whether to stay and live with the potential flood risk.   

There are people who have already sold their house because they can’t cope with the sound of rain,” Sebastian says. “They don’t want to live with the constant fear that this flash flood could happen again. I myself can deal with it, but I must admit it is always in the back of my mind.”  

Rebuilding in a Floodplain
The government has approved a €30 billion ($34 billion) fund to support those affected by the flood. Authorities have also published updated flood zone maps of the Ahr River Valley, showing where new construction is no longer permitted. Of the thousands of homes that were damaged, local authorities have said just 34 are not allowed to be rebuilt due to flood risk.

Most residents in the floodplain will be allowed to renovate and rebuild their homes as before, in the same spot. But there will be restrictions for those building from scratch. The details are still sketchy in the wake of the flood, but the regulating authority says this could include measures such as installing fuse boxes on the upper floors so that power supply won’t be interrupted by a flooded basement. 

It’s also not yet clear whether insurers will provide natural hazard coverage for residents rebuilding in a designated floodplain, says Sebastian. 

Live with Risk or Relocate?
Professor Christian Kuhlicke, an expert on environmental risks and extreme events at Leipzig’s Helmholtz Center for Environmental Research, says there needs to be “a fundamental change” in the way people build in small river catchments like the Ahr Valley, where homes are often unprotected from flood risk.  

Otherwise it becomes very costly and potentially also very deadly.”