Temporary bubble screen in the Amsterdam-Rhine Canal to stop salinisation

Published: 27 July 2018

Rijkswaterstaat West Nederland Noord has asked Deltares to advise on the use of a temporary bubble screen in the Amsterdam-Rhine Canal to stop salt penetration further into the canal. As drought conditions continue, the salt content in the North Sea Canal is increasing and there is now a possibility that salt may enter the Amsterdam-Rhine Canal.

Rijkswaterstaat West Nederland Noord has asked Deltares to advise on the use of a temporary bubble screen in the Amsterdam-Rhine Canal to stop salt penetration further into the canal. As drought conditions continue, the salt content in the North Sea Canal is increasing and there is now a possibility that salt may enter the Amsterdam-Rhine Canal.

Deltares is working with Rijkswaterstaat to see how it may be possible to create an effective bubble screen with simple resources. Because there is not enough freshwater to send to the sea through the Amsterdam-Rhine Canal and the North Sea Canal, the salty water that comes inland through the locks at IJmuiden can now flow further into the country. That has adverse effects on various water-dependent functions such as agriculture, nature and drinking water extraction.

The North Sea Canal is now becoming increasingly salty. There is a threat of the salt water moving into the Amsterdam-Rhine Canal. It has already been suggested in the past that a bubble screen should be installed at the entrance to the Amsterdam-Rhine Canal from the North Sea Canal as a counter-measure. A lot has been learned about the characteristics of an effective bubble screen from recent projects looking at ways to limit salt penetration, first at the Volkerak locks and then for the Krammer locks. Knowledge has also been acquired about the combination with flushing flows: water flowing through the bubble screen from the freshwater side to the salt side. That combination can also be used here. The bubble screen also reduces the speed at which the salt penetrates, making it possible to stop the salt effectively with a limited discharge rate through the Amsterdam-Rhine Canal.

Whether this measure can be used now depends on whether Rijkswaterstaat can find a contractor to build the bubble screen quickly. Deltares has provided a description in its report of an effective bubble-screen in the Amsterdam-Rhine Canal.