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Coastal protection

Increasing risks, Larger consequences

It is expected that by the end of the 21st century, the sea level will have risen by 20 centimetres. This means that the water of the North Sea will be standing 20 centimetres higher against the Dutch dikes and dunes. It is also predicted that within one hundred years, the sea level will rise by one metre! Regardless of whether it rises by 20 or 100 centimetres, the pressure on the Dutch coast will increase significantly. In the next century, much will need to be done to keep the Netherlands safe and dry. Besides the changes outside the dikes, many changes have taken place within the Dutch polders since the flood of 1953. Population and wealth have both increased over the last fifty years. A flood like the one of 1953 would therefore have larger consequences today than it had fifty years ago: more people would likely die and the financial and economic damage would be greater. Therefore are dikes not only necessary because the flooding risks are increasing, but also because the damage will be relatively worse. An increasing risk, with bigger consequences.

Safety

The Dutch government has been issuing notes on coastal protection to make the policy on coastal protection clear. In the year 2000, the Ministry of Transport and Public Works published the Third Coastal Note, named ‘Tradition, Trends and Future’. The main point of this note is that safety is not a goal as such, but more a goal that has to be balanced by the use of the available (public) space. Coastal areas do have a protective function, but they have other functions as well. From times immemorial, the dunes have always been a popular residential area. Moreover, people use the dunes for recreation and all kinds of plants and animals have made the coastal areas their habitat. Arguing in favour of more safety, implies less space for the other important functions of the Dutch coastal area. In the Fourth Water Management Note, the relationship between water management and environmental planning was stressed.

Water management of the 21st century

Sand suppletion has been used as a way to combat coastal erosion. By discharging large quantities of sand on the beach and below sea level in front of the beach, the dunes can be protected from erosion. Although the coastal areas are safe today, intervention is necessary to be sure the Netherlands will be safe in the future. In the long term, higher and broader dikes will be necessary. The rising sea level will eventually undermine the Deltaworks. Broader dikes, however, imply more space for waterworks. One of the questions is whether this space should be created inlands or seawards. Sand suppletion is a seaward activity, but it cannot be avoided that dike enlargement will take place inland. To face the future rise of the sea level, some areas will have to be 'surrendered' as coastal protection areas. In the province of Zeeland, this will be the southwest coast of Walcheren and the west of Zeeland Flanders. Most of the time, there is enough space available in dunes for the protection of the coast, although not in the proximity of the seaside resorts. A risk profile can be created for these cities and villages. Around many locations, a red line can be drawn, outside which new buildings and infrastructure is not allowed. In compliance with (1) coastal protection, (2) environmental planning and (3) nature and landscape, the Dutch coast can be managed.