A fascine mattress (Dutch: Zinkstuk, literally sink piece), is a large woven mat made of brushwood, typically willow twigs and shoots, used to protect riverbeds and other underwater surfaces from scour and erosion. They are similar in construction to a fascine, but are primarily used for hydraulic engineering works, typically to strengthen the banks of rivers and streams, as well as coastal structures like revetments and groynes.
Modern fascine mattresses utilise a layer of geotextile in order to fulfill the competing requirements of water permeability balanced with the need to be impervious to sand. Prior to the advent of synthetic geotextiles in the 1960s, a layer formed from reeds was incorporated to make the fascine mattress sand-tight.[1][2][3]
Fascine mattresses have been used worldwide,[4] but are particularly common in The Netherlands, where significant expertise in their preparation and construction is available, and where the materials required for their construction are harvested in specially created plantations.[5]