We measure chloride in Lauwersmeer

Last week, we took measurements by boat at the Cleveringsluizen. We investigated the chloride content of the water at various locations and at various depths. We also looked at the flow velocities and flow direction. This gives us a better understanding of how fresh and salt water move in Lauwersmeer. Based on our findings, we also determine where measuring buoys can provide the best insights. 

The measurements were carried out by Rijkswaterstaat Central Information Services, in close collaboration with the operational water managers of the Noorderzijlvest and Wetterskip Fryslân water boards. 

Why is this important? 

• More insight
  We are investigating how the water flows and how (to a limited extent) salt water flows into the lake. This is necessary for research into the possibilities for a better transition between fresh and salt water. The knowledge we gain from these sailing measurements will help us develop variants for a robust fresh-salt connection. Theresearch (the exploration)will continue until 2028. 

How do we take the measurements? 

• Safe and responsible
  We only take measurements when there is enough fresh water to flush away the salt. After the measurements were taken, the chloride content was comparable to the initial situation. The locks are only opened when there is a small difference in water level between the Wadden Sea and Lauwersmeer and when the tide is going out. This ensures safety for the lock complex and water quality.
• All measurements could be monitored by the administrators, allowing us to intervene if necessary.

What are the benefits?

• The measurements are already providing us with data that helps us better understand how the freshwater-saltwater dynamics between the Wadden Sea and Lauwersmeer can work at the Cleveringsluizen.
• We will also use the insights gained from this initial measurement campaign to determine where to place the measuring buoys in Lauwersmeer. These will be installed in early 2026.