Vienna was spared the worst of the flooding from severe weather earlier this month thanks to a large flood defence system that can manage even exceptionally big floods, a BBC investigation has found.

An expert quoted by the BBC, Günter Blöschl, a hydrologist and director of the Centre for Water Resource Systems at the Vienna University of Technology, says these measures enable Vienna to handle a flood discharge of 14,000 cubic metres of water per second, equivalent to a 5,000-year flood. A 5,000-year flood is an event with a 1 in 5,000 chance of occurring in any given year.

The last flood of that magnitude happened more than 500 years ago, in 1501.

During this month’s flood, about 10,000 cubic metres per second flowed through Vienna’s rivers and waterways.

Many of the city’s protective measures, including Danube Island (Donauinsel) and the New Danube, a rerouted arm of the Danube that is typically closed by floodgates, date back to the 1970s and were established following a devastating flood in 1954.

Austria invests approximately €60 million annually in flood protection, with new initiatives continually being implemented. This strategy includes regular training exercises for emergency workers, such as learning to set up mobile barriers to contain rising waters, alongside efforts to develop a more sophisticated and accurate forecasting system.

As a result of these measures, flood damage has significantly decreased. The 2002 flood caused damages of €3 billion, while the 2013 flood – considered one of the largest in the past two centuries – resulted in damages of less than a third of that, at €866 million.

The exact extent of the damage from this month’s flooding is yet to be determined.