History of the Hollandse Ijssel
The Middle Ages
The French occupation
At the time when Napoleon’s armies occupied the Netherlands (1795 – 1813), a Public Works inspector developed an improvement plan for the Hollandse Ijssel. His plan was to build a dam at the site where the storm surge barrier is currently situated at the moment, namely between Krimpen aan de Ijssel and Capelle aan de Ijssel. In his plan, the Ijsseldam would include three locks: one lock for shipping traffic and two more to improve the flow. The locks were required for a better flow to prevent the mouth of the Nieuwe Maas silting up. The ideas for this dam were thought up in the years after the storm flood of January 15, 1808, almost 150 years before the infamous disaster of 1953. However, the technical ingenuity of the present storm surge barrier cannot be compared to the well-constructed plans today.
The river becomes a sea arm
A century ago, the Hollandse Ijssel was dammed up near Gouda and a 30 kilometre section was canalised, which increased shipping traffic. By canalising a part of the Hollandse Ijssel, it is navigable for ships weighing up to 2000 tons. A big advantage of the dam is that the water level is no longer influenced by tidal movements, so the river’s dikes did not have to be raised.
Because of all the dams that were built over the centuries, the difference between low and high tide is now only 1.7 metres. You could easily say the Hollandse Ijssel is now a sea arm instead of a river. Nowadays, the river is connected with the river Gouwe (near Gouda) and it flows out in the Nieuwe Maas near Krimpen aan de Ijssel. This is where the storm surge barrier was built.