Remote control failed: North Sea water threatened to flood Amsterdam

A failed technical remote control system almost triggered a flood disaster in the Netherlands last November, which also affected the capital Amsterdam. The incident has now been investigated by Rijkswaterstaat, the Dutch authority responsible for water management and public works, and the results have now been presented.

During the incident on November 2, 2023, the gates of the IJmuiden lock and pumping station in the west of Amsterdam suddenly switched to manual operation after a sluicing in the middle of the night at around 3:52 am. Employees at an operations center in Schellingwoude, which is located 35 kilometers east of Amsterdam, did not notice the problem at first. At around 5:45 a.m., they became aware of the malfunction due to the rising water level and immediately sent a technician to IJmuiden, who closed the lock gates on site. By 7:24 a.m., water was flowing into the canal – during the stormy night. The water level rose by a total of 32 centimetres during this time.

Important infrastructure for flood protection

The lock and pumping station complex on the North Sea drains excess water from a large part of the western Netherlands into the sea. Its primary purpose is to protect millions of people from flooding and to prevent the inflow of water from the North Sea during high tides. Every year, around three billion cubic meters of water flow through the sluice or the seven pumps of the pumping station towards the sea. The system is used to control the water levels of the North Sea Canal, which leads to Amsterdam, and the Amsterdam-Rhine Canal.

The complex is essential for controlling the water levels of the North Sea Canal and the Amsterdam-Rhine Canal and the areas draining into these canals (which are managed by water boards). The North Sea Canal normally has a water level of -0.40 meters NAP (Normaal Amsterdams Peil – similar to sea level). Deviations from this must not be too great, as higher levels lead to flooding and lower levels affect large sea-going vessels heading towards Amsterdam.

Why the remote control failed

The investigation by external experts has revealed that deferred maintenance and changes to the software could have triggered the loss of function. However, the exact cause has not yet been identified. The fact that the rise in the water level was only noticed so late is also viewed critically. Nevertheless, the responsible authorities and companies reacted quickly and correctly once they became aware of the incident.

In response to the incident, the lock and pumping station complex is now being operated by staff on site again. Staff are in IJmuiden around the clock. An additional acoustic and visual warning signal has also been installed in the control room, which is triggered when the North Sea water level rises.

(mki)