Port maintenance and nature preservation are two often conflicting aspects of coastal management. Within a Pilot Project in the Western Wadden Sea (the Netherlands - see Figure1a) we test a win-win solution that could reduce harbour siltation while simultaneously stimulate saltmarsh development.For this purpose, fine material, dredged in the Port of Harlingen, is used to increase the bed level of the intertidal flats at North-East of the harbour. The sediment is not disposed directly on the mudflat but at the North-East edge of the Kimstergat Channel (Figure1b). The strategy is based on the presumption that the flood dominant system results in an extra net sediment transport onto the Koehool Mudflat (Figure1b). The imposed higher mud supply will gradually feed the mudflat (hence the name of the project: The Mud Motor) and is expected to accelerate the rate of bed level increase and, as consequence, the switch from a bare to a vegetated mudflat state.Environmental Fluid Mechanic