Innovative sediment management in the Scheldt Delta
The Interreg (Flanders – Netherlands) project Smartsediment, is financially supported by the European Union. It is a collaboration between Dutch and Flemish governmental bodies, NGOs and the knowledge center NIOZ. Smartsediment will evaluate different management strategies currently being executed in the Scheldt estuary and Oosterschelde and investigate how sediment can be used in a smart way to optimize biodiversity and ecosystem services in these systems.
The Schelde estuary is heavily dredged for navigation, and the dredged sediment needs to be relocated within the system. The question is if this can be done in a sustainable way safeguarding biodiversity and ecosystem services. In the Oosterschelde tidal flats are eroding as a consequence of the construction of the storm surge barrier in the mouth of this coastal bay. This has consequences for nature and safety, as the tidal flats are important feeding grounds for birds and protect the dikes against waves. Nourishing tidal flats is being proposed as a solution to mitigate the erosion, but long-term efficacy is still unknown.
Smartsediment aims to rebalance biodiversity, soil and ecosystem services in the delta by smartly dealing with the available sediment and the water base. The province of Zeeland collaborates with the Flemish Government to examine the effects of dredging, dumping and displacement of sediments at 15 locations in the delta. The main focus is on the Roggenplaat, an essential part of the intertidal area in the mouth of the Oosterschelde. The sand flat is raised for 200 hectares to counteract further erosion. In this way, migratory birds and seals can permanently use this area to feed.