From June to autumn 2025, Rijkswaterstaat will add 1 million m³ of North Sea sand at the mouth of the Western Scheldt. Due to tides and currents, the sand will gradually spread over the bed and towards the coast.
The sand also contributes to the safety of the hinterland. By nourishing the coast with sand, the Zeeland region remains protected from the sea in the long term.
Sailing with Less Emissions
The sand is applied to the seabed by ships from the Belgian dredging company Jan De Nul. These trailing suction hopper dredgers are equipped with Ultra Low Emission Vessel (ULEv) technology. Thanks to a combination of catalysts and filters, a large part of the nitrogen oxides (NOx) and fine particles from the exhaust gases are filtered out. Moreover, the ships run on 100% biofuel, significantly reducing CO₂ emissions compared to fossil fuels.
The actual emissions are continuously measured with a special emission monitoring system that Jan De Nul has developed together with us. This is the first time this combination of ULEv technology, biofuel, and monitoring is used for coastal maintenance. This innovation stems from the Innovations in Coastal Care program (2018–2024) of Rijkswaterstaat.
Research on Sand Displacement
During the work, we investigate how the applied sand moves from the mouth of the Western Scheldt, further up the river and along the coast. The sand is applied at 2 locations in the mouth of the Western Scheldt, at an average depth of 10 m below sea level, near the Vlakte van de Raan. We look at the effects of tidal currents and waves on the distribution of the sand.
During and after this underwater replenishment, we also examine the effects on the seabed life. The knowledge gained helps us to deploy underwater replenishments to allow the coast to grow with the rising sea level. The research is conducted in collaboration with the Maritime Access department of the Flemish government, within the Flemish-Dutch Scheldt Commission .