The fact that the Erft begins next to the playground in Holzmülheim is due to the fact that a layer of clay broke open in the mountain millions of years ago.

The clay lies like a lid over the limestone, which comes from the time when the Eifel was a sea, with coral reefs made of limestone.

At some point there was an opening in the clay through which, again much later, rainwater seeped into the mountain found its way out.

It flowed through the opening and towards the valley.

A river came into being.

The Erft is one of the more inconspicuous German rivers: on the map of Germany a delicate blue line that runs for a while next to the finger-thick Rhine and flows into it south of Düsseldorf.

In Holzmülheim, cyclists who ride the Erft cycle path are particularly interested in the stone spring.

There is a restaurant called "Erftquelle", where you can meet Yasin Yildiz.

He says that the river, which is still a stream here, has always been inconspicuous in the 47 years he has lived in the area.

You could almost forget him.

That's why Yasin Yildiz still can't believe what happened on July 14th.

Suddenly water seemed to be coming from everywhere.

It rattled from the sky, it shot out of the spring, it swelled into the stream that flooded the meadow with the playground and the houses in the lower part of the village too.

The Erft and the Flood

When Yasin Yildiz heard of the destroyed Bad Münstereifel, of the landslide in Erftstadt, of the dead and missing, he and his family decided to help.

They no longer cooked for guests in their restaurant, but for helpers and victims of the flood.

Word got around, more and more food was donated, more and more volunteers took part.

From the spring of the Erft, which had suddenly become a source of calamity, they delivered over a thousand servings of food a day for four weeks.

Almost everyone in Germany knows the Erft now. Your name will remain associated with the flood - and perhaps with the moment when people in Germany understood what global warming means. The research group World Weather Attribution, which investigates the extent to which heat, storms or heavy rain are related to climate change, took on the events at Erft and Ahr and found that the man-made rise in temperature has increased the probability of such extreme rainfall by up to nine times. This also means: rivers, part of the earth's water cycle, will remind us more often in the future that they are a piece of nature - something that humans have wanted to forget for a long time. For centuries, his relationship with rivers consisted of making them usable.

Castles, mills and power stations were built on the banks of the Erft. It was relocated, made wider, straightened, and now all of that is being reversed, it is being renatured. At 107 kilometers it is short, the Rhine is 1230 kilometers long, the Danube 2850. But a journey along the Erft is a journey through the whole relationship between man and river.