Long before the flood disaster in Rhineland-Palatinate and North Rhine-Westphalia, the Frankfurt authorities met under the leadership of the Environment Agency to draw up a so-called heavy rain hazard map.

Now, a year and a half later, it is available and freely accessible on the Internet via the city's geoportal.

"The presence of the card does not solve all problems," said Environment Officer Rosemarie Heilig (The Greens) at the presentation.

However, it helps to make citizens, property owners and property owners aware of the dangers.

The card contains information on where it is necessary to take precautions.

The city, too, so Heilig, has to rethink.

Too many areas were sealed in the past.

Changing this is a task for the city as a whole.

Mechthild Harting

Editor in the Rhein-Main-Zeitung.

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As Heilig explained, heavy rain often occurs suddenly and in a very limited space.

It is therefore impossible to predict where the water masses will be concentrated.

In the opinion of the city councilor, Frankfurt, unlike western Germany, experienced a “completely normal Central European summer” this year.

Nevertheless, on some days more than 15 liters of rain per square meter per hour fell in the Main metropolis.

Such an amount of weather experts speak of heavy rain.

Notes on climate change

The fire brigade was deployed eighty times in June alone and had to pump empty in Rödelheim and Niederrad Keller, for example: In Rödelheim, 26 liters per square meter had dropped per hour, in Niederrad even 50 liters. For Heilig, such downpours and the hot summers of the past are indications of climate change. Frankfurt has to reckon with more and more dramatic weather events, including more frequent heavy rain.

In addition to urban planning, the road construction department and urban drainage are also required, for which the mobility department Stefan Majer (The Greens) is responsible.

Majer rejected demands that the city should enlarge the sewers so that they could absorb the heavy rain.

It is true that the canals are being upgraded again and again: “Under Gutleutstrasse, the canal now has dimensions that a small car can fit through.” But the network cannot be expanded in such a way that it can cope with every heavy rain.

The cost of renovation work is already very high.

Of course, the city also reacts to the dangers that can be read from the map - even at short notice.

According to the map, the school on the slope in Bergen-Enkheim is an endangered place.

That will be taken into account in the planned new building, said Majer.

The city has clear priorities

Something has also been done at the Südbahnhof, which has already flooded several times in heavy rain, albeit not always as dramatically as in June 2016, when the water reached the subway tracks within a very short time.

The transport company installed several “hinged bulkheads” to prevent the water running down from the Sachsenhausen mountain from causing similar damage again.

A total of 1,800 areas in the city would be at risk if there were a “rain of the century” with more than 56 liters per square meter per hour.

Such a scenario is classified as “exceptional” and can nevertheless occur.

In such a case, 140 entrances to buses and trains would be affected.

There are clear priorities for the municipal authorities: First of all, hospitals, day-care centers and escape routes must be protected.

In road construction, too, attention has long been paid to better flood protection when building new roads or renovating roads: "Gullies" that collect the water are installed in closer succession and asphalt bumps are laid to divert the water.

The city has its homework to do, said Majer, but every owner of a building should also take precautions.

"The public sector cannot do all of this alone."

The heavy rain hazard map can be found at https://geoportal.frankfurt.de/starkregen.

Further information is available at the email address starkregenvorsorge@stadt-frankfurt.de and at 069-212-71409.