Reasons for the increase in flood losses

The increase in losses is a direct function of the number of people that live in exposed areas. Whilst the population pressure often leaves the people in poor countries with no other choice than to settle in exposed areas, the motivation in industrial countries is provided by other factors.

Flood plains are usually cheap as building land, attractive (being near a river), and easy to develop (being level). They offer good conditions for establishing the necessary infrastructure.

Flood plains are particularly advantageous for commercial and industrial facilities that need a large amount of space and sometimes use river water as process or cooling water. Larger rivers offer the possibility of transporting freight by ship.

Towns and cities are interested in further development. They have to make land available for development or for commerce and industry. Many owners are either not aware that there is a danger of flooding because they do not come from the region and assume that if land is released for development it will not be unsafe, or they ignore the danger.

Flood control measures make loss events less common

What is more, many people still believe that flood events can be controlled as long as appropriate technological precautions are taken. Flood control measures make loss events less common.

The positive effect is that frequent losses and discomfort can be prevented. This effect is counterbalanced, however, by the fact that the feeling of security it creates leads people to expose more and more objects of increasing value to the risk of flood.

This feeling of security is transmitted not only by dykes and embankments, early-warning systems, and the availability of disaster relief organisations but also by the intentional or unintentional transmission of false information and by local authorities or groups with a vested interest (e.g. the tourist trade) playing down the risk. If an event occurs which existing safeguards cannot cope with, an immense loss potential suddenly emerges.

Never before have people had so many valuable but at the same time vulnerable possessions. The rooms in the basement where people used to store coal and wood, preserves and potatoes, and all manner of junk, have now made way for party rooms and playrooms with wall-to-wall carpeting, upholstered furniture, stereos and computers, and freezers and washing machines.

The greatest problem, however, is presented by central heating equipment and oil tanks (the rule of thumb being that the original water damage is roughly doubled by escaping oil).

In larger residential or commercial buildings the subterranean floors often accommodate car parks, control panels for lifts and air-conditioning systems, materials stores, and sometimes even computer centres, as in the case of a bank in Dresden that was flooded in August 2002. Underground car parks may constitute a deadly trap.