Central Europe braces for further flooding as swollen rivers continue to rise

As swollen rivers continued to rise, volunteers and emergency workers in towns and cities across a swathe of central Europe were reinforcing defences against floods that have killed at least 21 people in four countries.

Storm Boris has dumped up to five times the average September rainfall on parts of Austria, the Czech Republic, Hungary, Poland, Romania and Slovakia in four days, submerging entire neighbourhoods and forcing hundreds of thousands of people to evacuate.

Seven people have died in Romania, six in Poland, five in Austria and three in the Czech Republic, officials said on Tuesday, with several missing. The rain was easing in some areas but water levels in others were not expected to peak for several days.

The Danube River had peaked in Slovakia, the environment minister, Tomáš Taraba, said, leaving parts of Bratislava’s old town flooded. It was still rising in Hungary, including by about a metre every 24 hours in Budapest. Mobile dams were in place at the historical towns of Visegrád and Szentendre, north of Budapest.

Tram lines and roads alongside the river, as well as the popular Margaret island, have been closed and a million sandbags distributed.

In eastern Germany, authorities were also taking precautions, with mobile flood protection walls set up in some areas to protect Dresden’s old city as the Elbe rose steadily. The river was expected to peak by midweek.

In Poland, the mayor of the historical city of Wrocław, Jacek Sutryk, said on Tuesday buses had been prepared for an evacuation. “Today we will also be further reinforcing embankments in the [Oder] river basin,” he said.

The Oder is expected to peak on Friday, or perhaps sooner, in the city, which is home to 600,000 people. Wrocław zoo, alongside the river, appealed for volunteers to fill sandbags. “We and our animals will be extremely grateful for your help,” it said.

Extreme rainfall is becoming more common and intense because of human-caused climate breakdown across most of the world, particularly in Europe, most of Asia, central and eastern North America, and parts of South America, Africa and Australia.

Warmer air can hold more water vapour, while human factors, such as flood defence planning and land use, are also important factors in consequent flooding.

Climate breakdown is also making heatwaves more intense and more likely to happen, increasing the risk of devastating wildfires. As rescue workers battled floods in central Europe, firefighters in Portugal fought fires that have killed seven people.

Near the border between Poland and the Czech Republic, one of the hardest-hit areas, 2,000 volunteers from the Polish town of Nysa’s population of 44,000 spent Monday night helping rescue workers build up a burst river embankment.

“Please evacuate your belongings, yourselves, your loved ones. It is worth getting to the top floor of the building immediately, because the wave may be several metres high,” the town’s mayor, Kordian Kolbiarz, had told residents on Monday night.

On Tuesday morning, the mayor said on Facebook that “women, men, children and the elderly” had come out to try to save their town. “We simply … did everything we could,” Kolbiarz wrote on Facebook. “We fought for Nysa. Our home. Our future.”

A huge reservoir near the border aimed at reducing water levels and preventing flood waters from the Odra and Nysa from merging – as they did in catastrophic flooding in 1997 – was about 80% full, authorities said.

Poland’s prime minister, Donald Tusk, on Monday announced an emergency relief fund of 1bn złotys (€200m) for flood victims in the country, adding that Poland would apply for EU relief funds.

In the Czech Republic, where more than 60,000 homes were still without electricity, the governor of the north-eastern Moravia-Silesian region, Josef Belica, said 15,000 people had been evacuated and helicopters were delivering aid to towns and villages cut off by flood water. Eight people were unaccounted for.

In the eastern city of Krnov, people were beginning to cart away debris on Tuesday. “All the pavements are destroyed, everything’s toppled, everything’s broken … It’s a nightmare,” Eliska Cokreska, 76, told Agence France-Presse.

The fire service delivered bottles of drinking water to villages cut off by the floods, with people told not to drink tap water as it would be heavily contaminated.

In Austria, the state of Lower Austria has been declared a disaster zone. The flooding has broken a dozen dams, with muddy rivers raging through devastated villages and thousands of households without electricity and water. Twenty-six communities were still cut off. As the weather improved, Johanna Mikl-Leitner, the state governor, said: “We are discovering the scale of the disaster.”

In the Austrian town of St Pölten, more rain has fallen in four days than in the whole of the wettest autumn on record 75 years ago. The army has been deployed across the region and a €300m emergency fund made available.

Weather in the region is expected to improve steadily from late on Tuesday, but Storm Boris is forecast to move to northern Italy, where the region of Emilia-Romagna is bracing for the impact of 100-150mm of rainfall.

Reuters, Agence France-Presse and Associated Press contributed to this report