Prolonged heavy rainfall across central Europe combined with a wet May has brought widespread flooding to much of Germany, Austria and the Czech Republic.
In response, Willis has mobilised field teams to document the evolution of the flood wave, survey the impact of the flood and inspect the flood defence structures along large stretches of the Danube River in Austria and Vltava River in Czech Republic.
The Willis survey teams comprise of trained hydrologists in conjunction with Willis Research Network members, supported by hydrologists and meteorologists in Munich and London.
Central and eastern Europe has experienced significant flood events in recent years, in particular in 2002, 2005, 2006 and 2010. Along the Danube, the river levels eclipsed previous records in Deggendorf, Passau and Korneuberg but most stretches of the Danube experienced lower water levels than in 2002. Observed water levels along the Elbe River in Czech Republic have remained below the August 2002 records.
Mounting a defence
Investment in flood defences has been widespread across the region over the last 10 years, largely driven by those areas affected in the 2002 flood, altering natural floodplain retention areas. Major cities and even smaller towns along the main tributaries of the Danube and Elbe Rivers have invested in so-called demountable flood defence structures, temporary structures that can be deployed in the event of a flood.
Throughout the region, emergency services are well prepared, completing evacuations of vulnerable settlements, installing demountable defence structures, regulating road closures and coordinating clean-up operations.
All along the Danube from Passau to Vienna, the countryside is a patchwork of flooded towns and villages and dry settlements protected by fixed and demountable flood defences. In Grein, a 5 m metal sheet wall protects a few hundred properties and in Klosterneuberg, the railway station and bypass is protected by a large engineered structure. Similarly along the banks of the Vltava in Prague, 2-3 m high defences protect large parts of the old town.
Road closures are enforced along the banks of the Danube and in low-lying areas behind flood defences where surcharge from drains and a high water table make roads impassable. Sandbags are placed on top of drain covers to ease the surcharge but even in areas where the flood waters are contained, the basements of many properties are pumping out litres of water.
In Emmersdorf and Melk, unprotected by major defences, the clean-up operation is well underway with local residents helping emergency services to remove the silt and water from the roads and begin the removal of damaged furniture and belongings – a sight echoed in towns and villages throughout the region.
The differences between 2002 and the present day are marked; emergency services and residents are prepared and swift to react, new defence structures have protected large sections of rivers but to the possible detriment of communities downstream and all eyes will now shift to the Elbe and Saale Rivers in Germany as the flood wave heads to the North Sea as the clean-up operation begins. The Willis Flood Team is monitoring how the event unfolds and is issuing updates.
Tim Fewtrell is Chief Hydrologist, Global Analytics at Willis. He is responsible for developing in-house flood risk assessment tools for clients in Willis and Willis Re. He is also responsible for co-ordinating the hydrological research of the Willis Research Network and leveraging cutting-edge science for Willis’ clients.