Flooding in Europe last month will cause more than 12 billion euros ($15.5 billion) of damage, the year’s most expensive natural catastrophe, according to Munich Re, the world’s biggest reinsurer.

Insured losses will probably be at least 3 billion euros, or more than $3.8 billion, with the majority of insured losses being in Germany, the Munich-based company said in an e-mailed statement today. The damage costs will approach the $16.5 billion of losses from the Elbe river floods of 2002, of which $3.4 billion were insured, Munich Re said.

Germany and Austria were among the nations stricken after unseasonably heavy rainfall caused the Vltava, Danube and Elbe rivers and their tributaries to burst dams and breach their banks. Insurers are counting losses after the waters retreated, with Swiss Re Ltd., the second-biggest reinsurer, saying yesterday that it expects about $300 million of claims.

“The frequency of flood events in Germany and central Europe has increased by a factor of two since 1980,” Torsten Jeworrek, a management board member at Munich Re, said in the statement. “Such a rise in losses can be prevented by better flood control.”

Munich Re didn’t say what claims the company faces. About 45 percent of the total $13 billion in insured losses in the first half were caused by inland flooding, the company said.

The natural disaster with the most severe humanitarian consequences this year was flash flooding in northern India and Nepal that killed more than 1,000 people, according to the German reinsurer.

Catastrophe modeling firm AIR Worldwide recently estimated the insured flood losses would be between $5.3 and $7.8 billion (EUR 4.0 billion and EUR 5.8 billion).

Editors: Keith Campbell, Mark Bentley