Opening gates in flood protection barriers along the North Sea Coast

Due to the effect of climate change, a rise in sea level has become unavoidable. Only 2 solutions are left: either to return large parts of the land to the sea, or to build obstacles and dikes to prevent the flooding. The latter is the most obvious. In Belgium, the 65 km long coastline, including the ports of Ostend, Zeebruges and Blankenberge, as well as the port and the City of Antwerp are risk areas for flooding. That is why an extensive plan of low walls has been drawn up, which will be built in the high‐risk areas. Evidently, openings are needed in these walls, so that emergency vehicles, or other necessary objects, can be brought to the beach. Movable sliding gates have been provided for this, which can be permanently closed in the event of spring tides or later on for more permanent situations. The most difficult point appears to be the load due to the seawater that must be assumed. However, it seems the load due to debris can be more detrimental than the wave action itself. Since one becomes fairly certain of future floods, these loads should no longer be regarded as accidental, but should be assigned a higher partial safety.