St. Mary Magdalene's flood, in German Magdalenenhochwasser, was the largest recorded flood in Central Europe with water levels exceeding those of the 2002 European floods. It occurred on and around the feast day of St. Mary Magdalene, 22 July in 1342.
Following the passage of a Genoa low the rivers Rhine, Moselle, Main, Danube, Weser, Werra, Unstrut, Elbe, Vltava and their tributaries inundated large areas. Many towns such as Cologne, Mainz, Frankfurt am Main, Würzburg, Regensburg, Passau and Vienna were seriously damaged. Even the river Eider north of Hamburg flooded the surrounding land. The affected area extended to Carinthia and northern Italy.
It appears that after a prolonged hot and dry period, continuous rainfalls occurred, lasting several consecutive days and amounting to more than half of the mean yearly precipitation. Since the dry soil was unable to absorb such amounts of water, the surface run-off washed away large areas of fertile soil and caused huge inundations, destroying houses, mills and bridges.
In Würzburg, the then-famous Steinerne Brücke was washed away, and in Cologne it is said that a rowing boat could pass over the city's fortifications. A precise number of casualties remains unknown, but it is believed that in the Danube area alone, 6,000 people perished. The results of the erosion can still be noticed today. The volume of the eroded soil during this short incident, a few days, is determined to be more than 13 billion metric tons, a volume that is washed away under normal climate conditions over a period of 2,000 years.
It is assumed that the loss of fertile soil led to a serious drop in agricultural production. In addition, the following summers were wet and cold, so that the population suffered from widespread famine. Whether the spreading of the Black Death between 1348 and 1350, killing at least a third of the population in Central Europe, was facilitated by the weakened condition of the population is a matter of discussion.
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In August 2002 a flood caused by over a week of continuous heavy rains ravaged Europe, killing dozens, dispossessing thousands, and causing damage worth billions of euros in the Czech Republic, Italy, Spain, Austria, Germany, Slovakia, Poland, Hungary, Romania, Bulgaria, Croatia, Ukraine and Russia. The flood was of a magnitude expected to occur roughly once a century. Unprecedented flood heights were recorded and at least 110 people died.
In December 2002, total economic damage estimates exceeded 15 billion Euro, of which 15% was insured.
Flooding resulted from the passage of two Genoa low pressure systems, named Hanne and Ilse by the Free University of Berlin, which brought warm moist air from the Mediterranean northwards. The effects of El Niño are believed to have possibly contributed, although others disagree. The floods gradually moved eastwards along the Danube, although the damage in the large cities on its shores was not as severe as in the areas affected by the floods later.
When the rainfall moved northeast to the Bohemian Forest and to the source areas of the Elbe and Vltava rivers, the results were catastrophic water levels first in the Austrian areas of Mühlviertel and Waldviertel and later in the Czech Republic, Thuringia and Saxony. Several villages in Northern Bohemia, Thuringia and Saxony were more or less destroyed by rivers changing their courses or massively overflowing their banks.
The floods that hit Europe during August 2002 were part of a larger system that was also affecting Asia. Several rivers in the region, including the Vltava, Elbe and Danube, reached record highs.
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