Thousands of emergency workers, troops and volunteers in Germany battled Sunday against central Europe's worst floods in over a decade, which have forced mass evacuations and which one politician termed a "national catastrophe".

The focus was on the eastern city of Magdeburg, where vast outlying areas were covered in a sea of brown water, sparked by recent torrential rains which have washed down the Elbe river system from the Czech Republic.

The water level in Magdeburg reached 7.45 metres (24 feet) in the morning, vastly higher than the usual level of around two metres and worse than massive floods that struck the region in 2002, local authorities said.

Almost 3,000 residents were evacuated from the city's Rothensee district, where hundreds of army troops were working to reinforce a dyke protecting a crucial electricity facility to prevent a wider power outage in the city.

More townships were evacuated around Barby, where the Saale tributary meets the Elbe. Some of the 8,000 residents of the nearby town of Aken were taken to safety on military armoured personnel carriers and ambulances.

President Joachim Gauck was due to visit the flood-hit states of Saxony and Saxony-Anhalt on Sunday and join a church service with emergency crew and residents in the town of Halle.

Chancellor Angela Merkel's government was planning a crisis meeting with state premiers to assess how their governments will share the cost of the disaster, the Leipziger Volkszeitung daily reported in its Monday edition.

"We're dealing with a national catastrophe," Gerda Hasselfeldt, lawmaker for the conservative Christian Social Union, who chairs a group of states in the Bundestag, told the newspaper.