Are the protection requirements for the Netherlands absurdly high? Other countries are much less strict.

The Netherlands has the highest protection standards in the world for preventing floods. Those standards were established after the 1953 floods, which killed more than 1,800 people. They are set out by law and there are reasons why they are so strict. 

The Netherlands is a densely-populated and low-lying country. Approximately nine million people in the Netherlands live behind dikes and dunes in areas that could be flooded if we fail to defend them properly. There is a huge amount of capital invested in these areas. We saw the consequences of inadequate protection in the Netherlands in 1953 and many other times when there was actual flooding or a serious threat. A high level of protection is not a luxury for the Netherlands; it is a necessity. 

Since 1953, the consequences of flooding have changed, in part because more people now live behind the dikes, where the economic value of the assets has increased. With the Delta Decisions, the Delta Programme has proposed new standards for flood risk management that match the current risks and the possible scenarios for climate change and socio-economic development over the next fifty years. The government has decided to adopt these new standards as law.