Test with reef blocks of silt from the Ems-Dollard

Over the next five years, research will be carried out on how to underwater life in the Ems-Dollard and Wadden Sea can be stimulated with reef blocks of Groningen clay. The project is being carried out at two locations in front of the sea dike between Delfzijl and Eemshaven. On the hard surface of reef blocks, mussels and oysters can attach themselves and build a new reef. For this, 400 blocks will be placed near the Eemshaven and the Bierum beach. The reef elements are made of dredging sludge from the port of Delfzijl. The project should show whether the shellfish return to the Ems-Dollard and whether this creates a new habitat for underwater animals and plants.

It is the first time that reef blocks have been made from silt from the Ems-Dollard.

The use of dredging sludge from the port of Delfzijl has two advantages. The water of the Ems-Dollard becomes less muddy and the dredging sludge is given a second life as a circular building material.

The hundreds of reef blocks were pressed in October with a new technology developed by Geowall, a collaboration between engineering firm Netics and dredging company Van Oord. The dredging sludge was dried in the ‘clay ripening plant’ in Delfzijl. This clay depot has now been dismantled for the construction of the Brede Groene Dijk near Finsterwolde.

Photo: Province of Groningen

The province of Groningen is the client for the trial. Partners of the pilot project are Netics, Van Oord, Geowall, Waddenfonds and Groningen Seaports. The Rif Blocks pilot is part of the Rijke Dijk project of the Noorderzijlvest water board

Bron: Provincie Groningen>