Dams in the Netherlands have never been stronger so the probability ofencountering floods from rivers or on the coast similar to the greatflood in the south-western part of the Netherlands in 1953 has declined. However, the risks of casualties and economic damage from flooding havebecome much greater since this event. The controversy intimated here(decreased probability of flooding vs. increased risks of casualties andeconomic damage) has been largely attributed to a creeping discrepancybetween the existent set of design standards for dike strength (used fordam assessment and reinforcement programmes in the Netherlands) andcontinuing social and economic development. These standards, set down innational law, are, to a large extent, based on insights gained in the1953-1960 period. The present spatial distribution of economic interestsattached to the "dike-ring" areas (vulnerable lands protected by a singlering dike) is no longer in proportion to the spatial variation ofsecurity standards. Besides, the public no longer seems to considerflooding in the Netherlands as a natural hazard but rather as a sort ofexternal risk such as industrial hazards and plane crashes. The risks ofcasualties due to flooding in the Netherlands are much greater than theknown combined external risks. Compared to other countries in Europe,and the USA and Japan, the safety levels of dams in the Netherlands arealready much higher, based as they are on the high vulnerability of thepopulation in the Netherlands, with its low-lying areas, dense populationand large investments. A further increase in flood risks is expected dueto the rise in sea level, climate change, and further economic and socialdevelopment. Technical solutions no longer form the sole answer to thisincrease. Up till now focus has been on reducing risks of dike breachesby technical means, while efficient solutions in spatial planning havebeen overlooked. Solutions presented here include avoidance strategiesfor floodprone areas and the construction of compartment dams forsplitting up large floodprone areas into smaller ones. Political supportis essential, however past experience has shown that political interesthas the tendency to rapidly decline after disasters.
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