Karlsruhe strengthens heavy rain protection: Basin in Stupferich is being expanded!

Karlsruhe strengthens heavy rain protection: Basin in Stupferich is being expanded!

An important step is being taken in the city of Karlsruhe to offer citizens better protection against heavy rain events. In the high-altitude district of Stupferich, the city's smallest rain retention basin is being expanded. With an investment volume of 1.7 million euros, the existing basin, which has been able to store over 7,500 cubic meters of water since its inauguration in 2001, is to be enlarged to around 21,000 cubic meters. This is intended to significantly improve protection against floods and extreme weather conditions, which are exacerbated by climate change Karlsruhe.de reported.

The construction work, which began in March 2025, assumes that such heavy rain events, in which an extremely large amount of precipitation falls in a short period of time, are now occurring more frequently. The mayor Daniel Fluhrer and civil engineering department manager Martin Kissel explained the necessity of the expansion. In particular, the increasing amounts of precipitation in the summer months pose major challenges for cities. During a recent heavy rain event in August 2016, the basin was at its capacity limit, and an “in-depth safety review” revealed that the existing protection level was only effective for 10-year flood events, making the current expansion particularly urgent, he said bnn.de.

The background of the project

The dangers caused by heavy rain are not a thing of the future, but are already a reality. Studies show that the frequency of such weather phenomena has not decreased. A project by the Federal Environment Agency aims to support communities like Karlsruhe in adapting to these climate changes. Measures to prevent heavy rain are therefore more important than ever before. The city of Karlsruhe has decided on a comprehensive plan to counteract the effects of extreme weather events. The sewer system in the region will also be adapted to future requirements with an outflow of 200 liters per second Umweltbundesamt.de emphasized.

A particular focus of the project is to integrate the environment around the retention basin. There will be no fence around the pool, so birds and insects can be accommodated in a temporary nesting area during construction work. The measure aims not only to prevent flooding, but also to preserve nature and expand the habitat of wildlife accordingly.

Future prospects

The construction work is scheduled to be completed in autumn 2025. With the expansion of the rain retention basin, the capacity will be increased by almost three times the volume, which corresponds to around 140,000 full bathtubs. This investment in infrastructure and flood protection shows that the city of Karlsruhe is ready to actively meet the challenges of climate change. Such projects ensure that residents will continue to be protected, not only from heavy rainfall, but also from the congestion that comes with it. The existing pool will remain functional throughout the construction period, minimizing the risks for the local settlements.

Karlsruhe clearly has a good hand when it comes to dealing with the challenges of climate change and preparing the city for future weather extremes. Last but not least, it is important that all residents are included in the discussions about heavy rain prevention, because climate change can only be overcome together.