Salinization is the process by which the salt salty water enters the Dutch rivers and penetrates the groundwater. This is undesirable. This is why a number of measures have been taken in the Netherlands to counteract this process.
Apart from the fact that the dams on the Lower Rhine have been constructed to channel this river, they also have the task of preventing the salinization of the IJsselmeer.
Delta works. Even after the completion of the Delta Works, larger parts of the surface water in the west of the Netherlands have become fresh as a result. Plans have already been realised to reopen the Haringvliet locks, for example, on a limited scale, so that the Hollandsdiep and Biesbosch will come under the limited influence of the tides again.
In order to keep salt and fresh water separate when ships are being locked, a so-called bubble lane was installed in the Volkerak locks at the time. Air bubbles had to separate the salt from the fresh water. However, this solution is not 100% sufficient to keep the salty water out of the Hollands Diep. When the Krammer locks were taken into use, the bubble lane in the Volkerak locks was no longer necessary
During the construction of the Krammer locks, a very special way of separating salt and fresh water was devised. We work with different basins. Because salty water is heavier than fresh water, two levels of water form in the basins. The salty water is pumped out of the fresh water by means of a system of holes and pipes and kept on the salt side. In this way a much better separation of salt and fresh water is obtained than with the bubble lane, which actually only makes an air curtain between the two types of water.