History of the Hollandse Ijssel

The Middle Ages

Frontal view of the Stormsurgebarrier
The Hollandse Ijssel flows in a westward direction to the North Sea, through the provinces of Utrecht and South-Holland. Up until the end of the 13th century, the Hollandse IIssel was a wide arm of the river Rhine, but between 1285 and 1292 it was separated from the river Lek by a new dam. The river was blocked off at Klaphek, near Utrecht, by Duke Floris V. The chances are that at the time, the river was blocked off because of the danger of flooding in the surrounding areas. However, because the river became silted up, it lost its ability for shipping traffic.

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.