What if the dikes break?

Early in the morning of 26 August 2003, during a heat wave, a dike in the Dutch town of Wilnis broke. The flooding was stopped within four hours, but the costs weighed in at 16 million euros due to damage caused to the surrounding roads, the natural environment and the dike itself.

That 16 million euros does not include the economic hardship suffered by businesses and households during and after the flood. The figure would have been much higher if it had.

The event in Wilnis shows that a mixture of weather conditions can cause flooding in surprising ways. In this case, it was the combination of heat and drought, which made the peat in the dike contract and burst, ultimately causing the dike to break.

The Wilnis dike was on a ring canal. But what if the IJsselmeer Dam that holds out the sea were to break? Although the chances of that happening are ‘slim’, and predictions are ‘not unfavourable’, there are also numerous uncertainties.

It’s extremely difficult to assess the likelihood of future flooding, especially if you analyse this at specific locations. That’s why our economists decided to study the likelihood of flooding and the macroeconomic impact of flooding separately.

Discussion document

Our economists’ analysis identifies the economic impact of flooding in the Netherlands. This report is mainly intended to spark a discussion on the consequences of climate change.

To read the full report go to ABN AMRO insights.