Delta Plan of the Rhine

Under the Delta Plan, designed to protect 15,000 sq.km/5,800 sq.mi of land, the various mouths of the Rhine, the Maas and the Schelde, with the exception of the Nieuwe Waterweg and the Westerschelde, have been closed by dams. The tidal waters of the Oosterschelde are enclosed by a storm-surge barrier which is fully closed only in the event of a storm tide.