Can nature itself save us from the effects of climate change?
Extreme weather is on the rise worldwide: heavy and severe rains, flash floods and landslides have also occurred in Germany. One study warns that seven times as many people will be threatened by flooding in the next 25 years.
The wrong strategies have also led to dangerous floods. For years, cities and municipalities relied on ever higher and more stable dams. The consequences were dramatic, as the water would find a way. But now, Europe is rethinking its strategy. “Let the water in” is the new approach, pioneered by engineers in the Netherlands. In Dordrecht, rather than using increasingly massive dams in the event of flooding, the city makes space for water. Playgrounds, sports facilities and whole residential areas are built in a way that absorbs rising water levels, without the houses getting their “feet” wet. “We have a system where nature helps and protects us from the consequences of climate change and rising sea levels,” says Marcel Stive, professor of hydraulic engineering.
The cathedral city of Cologne has also learned from previous floods. Along the Rhine River, alluvial meadows absorb water, while special pump systems and mobile flood barriers help protect the city.
The floodplain valley near Lenzen in Brandenburg is also a success story. The old dike was cut through, restoring 420 hectares of floodplains. Nature is thriving there. “Rare species such as the white-tailed eagle and the whooper swan have found a new home,” says floodplain researcher Meike Kleinwächter, “and that attracts tourists.”
The French town of Nevers realized years ago that a river should not be constricted. Fallow land, floodplain forests and marshlands have been established at the confluence of the Loire and Allier rivers. These measures render the river more predictable and less dangerous during floods.