In July 2021, several European countries were affected by severe floods. Some were catastrophic, causing deaths and widespread damage. The floods started in the United Kingdom as flash floods causing some property damage and inconvenience. Later floods affected several river basins across Europe including Austria, Belgium, Croatia, Germany, Italy, Luxembourg, the Netherlands, and Switzerland. At least 243 people died in the floods, including 196 in Germany, 39 in Belgium, two in Romania, one in Italy and one in Austria.
Belgian Minister of Home Affairs Annelies Verlinden described the events as "one of the greatest natural disasters our country has ever known." German minister-president Malu Dreyer of the Rhineland-Palatinate state called the floods "devastating". In addition to the confirmed fatalities, the flooding led to widespread power outages, forced evacuations and damage to infrastructure and agriculture in the affected areas. The damage to infrastructure was especially severe in Belgium and Germany. The floods are estimated to have cost at least €2 billion (US$2.35 billion) in insured losses, with the total damage costs being much higher, amounted to be €46 billion (US$54 billion). In the aftermath, scientists, activists and reporters all highlighted the connection to global trends in extreme weather, especially more frequent heavy rainfall caused by climate change.
Weather events
Between 12 and 15 July 2021, heavy rain fell across the United Kingdom, western Germany, and neighbouring Netherlands, Belgium, and Luxembourg. A storm complex moved east from France into Germany and stalled over the region for two days. Precipitation was intense in the East of Belgium, with 271.5 millimetres (10.69 in) of rain over 48 hours in Jalhay and 217 millimetres (8.5 in) over 48 hours in Spa. Heavy rainfall was also seen in the south of North Rhine-Westphalia and north of Rhineland-Palatinate in Germany where accumulations averaged 100 to 150 mm (3.9 to 5.9 in) in 24 hours, equivalent to more than a month's worth of rain. In Reifferscheid, 207 mm (8.1 in) fell within a nine-hour period while Cologne observed 154 mm (6.1 in) in 24 hours. Some of the affected regions may not have seen rainfall of this magnitude in the last 1,000 years. Floods started in Belgium, Germany, the Netherlands, and Switzerland on 14 July 2021 after record rainfall across western Europe caused multiple rivers to burst their banks.
The European Flood Awareness System (EFAS) issued alerts of life-threatening floods in advance, which, although very vague, were delivered to national authorities.
Impact
Austria
On 17 July, a flash flood swept through Hallein, a town close to the German border. Rescue workers in the states of Salzburg and Tyrol were placed on high alert for flooding, and Chancellor Sebastian Kurz tweeted "heavy rains and storms are unfortunately causing severe damage in several places in Austria." A man died in Saalbach-Hinterglemm during the floods.
Belgium
On 15 July, all residents of the city of Liège with a population of approximately 200,000 were urged to evacuate amidst fears that the Meuse river was on the verge of bursting its banks and that a dam bridge could collapse. No vehicles were allowed into the city centre of Liège; traffic was only allowed to leave as part of the evacuation. By 16 July, several smaller municipalities in Limburg Province were also given the order to evacuate. In addition, due to the heavy flooding and because tens of home fuel tanks had broken loose and started leaking into rivers, a number of municipalities in Liège and Namur provinces were left without potable tap water. Around 41,000 households were left without electricity in Wallonia. Foundations of buildings near rivers became eroded and buildings collapsed. In the town of Pepinster on the banks of the river Vesder, at least 20 houses collapsed and 23 of the 31 casualties as of 18 July were found here. The town of Verviers was also badly affected and has more than 10,000 of its residents having to be moved because of homes having become uninhabitable. Looting was also reported.
Precipitation was most intense in the east of Belgium, with 271.5 millimetres (10.69 in) of rain over 48 hours in the municipality of Jalhay, in the province of Liège—an absolute record for Belgium, almost three times the average rainfall over one month in this location for July. In the town of Spa, also in Liège, 217 millimetres (8.5 in) of rain fell over 48 hours.
An empty passenger train derailed at Grupont when the track bed was washed out by floodwater, with debris strewn across the track. The Charleroi–Namur–Liège line, and all railway lines in Belgium south east of that line, were closed. The overall damage to the rail network was estimated to take several weeks to repair. Early estimates also pointed to severe damage to the agricultural sector of the country, including long-term effects like soil erosion. During the flooding itself, farms and livestock had to be evacuated and many fields were damaged and crops destroyed by inundation. The Circuit de Spa-Francorchamps suffered damage to access roads and its digital safety infrastructure. The circuit was due to hold the 2021 Belgian Grand Prix on 29 August; damage was repaired sufficiently to allow the race to go ahead, although it was ultimately cut short after just one lap by further torrential rainfall and flooding at the circuit.
Belgian Prime Minister Alexander De Croo declared 20 July a national day of mourning.
In the evening of 24 July, southern and central parts of Belgium were hit again by severe flash floods as a result of intense but shorter thunderstorms. Particularly the city of Dinant and its surroundings in the province of Namur were badly hit, where tens of floating cars resulted in a pile-up and in damage to railroads.
Croatia
The Slavonia region was affected by floods. Communities such as Našice, Županja, Nova Gradiška, and Osijek were flooded and heavy rain caused serious damage, especially for farmers. No deaths were reported.
Czech Republic
Heavy rainfall led to flooding especially in North Bohemia, and several communities near Česká Lípa had to be evacuated. The country promised emergency aid to those affected by the floods of up to 57,900 koruna (2270 euro).
France
According to Météo-France, between 12 July, 8:00 and 16 July, 12:00, 199 millimetres (7.8 in) of rain fell in Châtel-de-Joux (Jura), 160 millimetres (6.3 in) in Plainfaing (Vosges), 159 millimetres (6.3 in) in Le Fied (Jura) and 158 millimetres (6.2 in) in Villiers-la-Chèvre (Meurthe-et-Moselle).
No deaths were reported.
Germany
With at least 184 deaths, the floods are the deadliest natural disaster in Germany since the North Sea flood of 1962. 1,300 people had been initially reported as missing on 16 July, but mostly due to mobile networks being down in some regions which made it difficult to call people. It was considered unlikely that the number of deaths would rise that high, and while on 19 July the exact number of missing persons remained unclear, a search was ongoing for at least 150 people. Some 15,000 police, soldiers and emergency service workers were deployed in Germany to help with search and rescue.
During the floods, 135 people died in Rhineland-Palatinate (all of whom were in the district of Ahrweiler), 47 in North Rhine-Westphalia (twenty-seven of whom in Euskirchen), and two in Bavaria. Four firefighters were among the dead. Westnetz, Germany's biggest power distribution grid, stated on 15 July that 200,000 properties in the North Rhine-Westphalia and Rhineland-Palatinate regions were without power, and that it would be impossible to repair substations until roads were cleared. On 16 July, around 102,000 people were still without power. The German Weather Service reported that the quantity of rain in some areas of Germany was the highest in over 100 years, possibly higher than any seen in the last 1,000 years. They reported that some areas had received a month's average rainfall in one day.
Some of the worst damage from the flood was in the district of Ahrweiler, Rhineland-Palatinate, where the river Ahr rose, destroying many buildings and causing at least 110 deaths. The topography of Ahr valley in western Germany, with some sections resembling gorges, may have exacerbated the effects of the heavy rainfall. The flooding here was the worst since 1910 when up to 200 people were killed in flash flooding. On 14 July, the city of Hagen declared a state of emergency, after the Volme river started overflowing its banks. The village of Kordel in Trier-Saarburg, which has around 2,000 residents, has been completely cut off. Several rivers reached their highest water level to date, including the Kyll, which rose from an average level of 1 metre (3.3 ft) to 7.85 metres (25.8 ft).
A study published in Nature Communications presents a high-resolution, impact-based early warning system for riverine flooding, demonstrated using the 2021 European Summer Floods. The researchers used numerical weather prediction and hydrodynamic modeling to generate near-real-time flood inundation and impact forecasts, providing authorities with up to 17 hours of lead time. Their findings highlight the need for integrating such high-resolution forecasts into operational flood early warning systems to improve disaster preparedness and response.
On 15 July, Thalys train services to Germany were suspended, and Deutsche Bahn stated that many rail services in North Rhine-Westphalia were also cancelled. Deutsche Bahn reported that over 600 kilometres (370 mi) of track was affected in North Rhine-Westphalia. The Cologne–Wuppertal–Hagen–Dortmund and Cologne–Bonn (Main Central Station)–Koblenz lines were closed. The Cologne–Bonn Beuel–Koblenz line remained open, but trains were subject to delay and cancellation. Customers were asked to avoid travel within and to North Rhine-Westphalia by train. The train connection from Dresden to Prague was also suspended after mudslides buried the tracks. Along the Ahr Valley Railway, at least seven railway bridges have been destroyed.
In Blessem, floodwaters of the Erft river inundated a quarry on 16 July, leading to a major landslide with several people possibly dead. Several buildings collapsed including parts of Burg Blessem. Around 40 meters of the nearby Bundesautobahn 1 broke away and fell into the Erft, but no cars were on the highway since it was closed. Experts voiced concerns on 15 July that the Steinbachtal Dam was unstable and could burst, and 4,500 people were preemptively evacuated from parts of Euskirchen, and later several thousand more from parts of Rheinbach and Swisttal. Drones were deployed to inspect the dam; while no cracks were found, local politicians said the situation as of 16 July remained "critical". Several other dams in North Rhine-Westphalia, such as the Rur Dam, were also overflowing, but there were no concerns about their structural integrity. Regardless, on 16 July a dam of the Rur burst near Wassenberg, prompting the evacuation of Ophoven. Around 360 inmates had to be evacuated from a prison near Euskirchen due to a failing supply of water and electricity. In Eschweiler, all of the more than 300 patients of the St.-Antonius-Hospital Eschweiler had to be evacuated. The neighbouring town of Stolberg was also badly affected in the town centre and three districts. On 14 July, in Hagen, a veteran soldier rescued a 13-year-old girl who required mechanical ventilation as well as two elderly people using a MAN KAT1 which was usually exhibited in a local museum, after regular rescue vehicles were unable to get there in time.
Strong rainfall also led to flooding in the states of Baden-Württemberg and Saxony. As of 15 July, one person in Saxony remains missing.
Further strong rainfall on 17 July caused flooding in Saxony and Bavaria e.g. Berchtesgadener Ache, where at least one person died. The flooding damaged the Königssee bobsleigh, luge, and skeleton track where it washed away part of the track that will take until October 2022 to rebuild.
Direct damage caused by the flooding in Germany was estimated at €33.4 billion (US$39.3 billion) with further €7.1 billion (US$8.36 billion) in indirect damage.
Italy
On 14 July, the storms reached Northeastern Italy and caused damage to agricultural crops. In Trentino-Alto Adige, a fallen tree damaged a cable car and several roads were damaged, and in Veneto one person died.
Luxembourg
In Luxembourg, hundreds of people were evacuated from their homes in Echternach and Rosport. Many homes in Mersch, Beringen and Rollingen lost electricity. The camping ground in Rosport had to be evacuated as a matter of urgency early on Thursday morning. Six people were brought to an emergency shelter in Osweiler cultural centre. Rosport sports centre was also used as emergency accommodation for people made to leave their homes. Mayor Romain Osweiler of Rosport explained the two buildings had been selected because they were accessible to people across the municipality.