Giving water space is important for flood protection in Solinger Land

Solingen – Photos of the flood disaster in mid-July in parts of Rhineland-Palatinate and North Rhine-Westphalia made many people think: could such events also occur in the Solingen region?

Claudia Schmidt of Sweden is aware of this concern: She is responsible for the “Above Ground Waters” section of the Solingen branch of the Lower Saxony State Office for Water Management, Coastal Conservation and Nature (NLWKN) and has been dealing with flood protection here since 2004. “We have already received a lot of inquiries from citizens. These questions do not appear to be completely unfounded, as on a map in Sulinger Land available on the NLWKN website, as well as Great Aue, Sule, and Siede marked as bodies of water that can cause especially great damage, floods. “We have to differentiate here,” says the expert. “HQ100” events were defined for this purpose, i.e. flood events because they can statistically occur once every 100 years – “We checked if flooding could happen there at all.” They also had the opportunity to refer to the Prussian documents to undo the previous floods. The affected areas were then examined at the site and compared with the terrain, and the county of Diepholz identified floodplains from this. Only in the case of Große Aue is the European Flood Management Directive applied as an additional point. In accordance with this, “HQextrem”, that is, events that occur statistically only every 200 years or less, as well as the most frequent events, more precisely “HQ20” to “HQ25”, were taken into account, for example, the flood of 1998. From this, NLWKN has calculated the danger zones, Sweden’s Claudia Schmidt explains.

However, a distinction must be made between floods that occur and heavy rain events that occur at some point in time. This was the case in July: in places, for example in the Cologne-Bonn region, more than 150 liters of rain fell per square meter in 24 hours, according to the German weather service. Claudia Schmidt-Sweden knows that even in the case of significantly smaller volumes, it can also happen in our region, for example, that the railway tunnels are flooded or the sewage system is no longer able to absorb the volumes of water.

Flood protection is a municipal issue

Municipalities are responsible for flood protection. Fortunately, Solingen has already established several rainwater holding basins, for example.

Essentially, however, the water has to be given space in the area. It becomes difficult when the settlement reaches a body of water, but “the advantage of a rural area is that we have space in the area”. And the water will always find its way. But the recommended procedure is that small floodplains are created in the form of floodplains.

No urgent need to take action in case of flood

The association for the maintenance of recreation and landscape Große Aue is very active: “It is a legal task of recreation associations to ensure proper drainage of water. Here, more attention has been paid to environmental issues for years,” explains Claudia Schmidt of Sweden.

The expert sees no urgent need for action in the event of a flood in Solinger Land. “It can always happen that the basement overflows or the water stops.” It is especially important not to seal in too much soil so that water can seep away as long as the soil is not saturated.

NLWKN presents on its site website Various additional information about flood protection. Available for download over there A detailed brochure with useful information is also available. Connected The current water levels of the various bodies of water in Lower Saxony can also be viewed.