Experts: Extreme weather on the Ahr was foreseeable beforehand

Created: 01/14/2022, 17:52

The railway bridge over the river Ahr in Altenahr, destroyed by the flood.

© Boris Roessler/dpa/Archive

"There is an extreme event coming": meteorologists, water scientists and geographers testify in the investigative committee on the flood disaster.

Were there any oversights surrounding the flash flood?

Mainz - According to several experts, even before the flood disaster in mid-July in the north of Rhineland-Palatinate, it was foreseeable that extreme weather events would occur.

For the meteorologist Sven Plöger it was clear two days before the flood disaster, "there is an extreme event coming," he said on Friday before the flood disaster investigation committee of the Mainz state parliament.

The television presenter said that he had expected rainfall of 100 to 200 liters per square meter in western Germany.

However, this could just as easily have hit the Black Forest as the Ahr region and the Sauerland.

Warning two days before disaster

The regional effect was not readable until July 13th.

However, he had already warned two days before the disaster: "Be careful on the rivers, watch the gauges, get away from the rivers," said Plöger.

"I didn't know that the Ahr level would rise to over nine meters, and I claim nobody knew that either".

In the night from July 14 to 15, 2021, a flood disaster occurred in northern Rhineland-Palatinate.

135 people died, 134 of them in the Ahr Valley.

Hundreds were injured and much of the valley was devastated.

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An overview of the temporal developments before the flood showed a 74 percent probability of a flash flood in individual smaller river areas of the Middle Rhine and the Moselle as early as noon on July 13th, the water scientist Jörg Dietrich explained to the investigative committee.

There were first signs of the extreme weather on July 11th.

On the evening of July 12th and during the course of July 13th, the predictions became more concrete.

From then on, one could assume that "flooding on the Ahr is very likely".

DWD had issued the highest possible warning level 4

According to the meteorologist Bernhard Mühr, the warning from the German Weather Service (DWD) was "early and factually correct". The DWD issued the highest possible warning level 4 before continuous rain on July 13th. However, he doubts that the explosiveness and the pressure to act from the text of the DWD could be recognized by everyone. And added: "There are too many warnings in Germany."

For professionals and in the communication between the municipalities and authorities, the pressure to act after the warning should have become clear, and he had difficulty understanding why the reaction was too late, said Mühr. In his view, from 4 p.m. it should have been done what the plans for such situations envisaged. He also doesn't understand why there weren't requests for campsites and residents to park their cars away from the shore as early as July 13th.

According to the geographer Heye Bogena, there is a flood event in the Ahr Valley on average every fourth year.

The main reason is the subsoil of the Rhenish Slate Mountains with thick layers that have few cavities or pores and can therefore hardly store any water, he said.

Due to a lot of precipitation in June and July 2021, he assumes that the soil was already about 50 percent saturated on July 14 when the heavy rain started.

"That has certainly aggravated the situation a little." dpa