Observations and analysis of fluid mud dynamics at Holwerd, the Netherlands

Holwerd is a small harbour at the Wadden Sea coast (the Netherlands) where the ferry to the barrier island Ameland departs. Over the past decade, siltation of the navigation channel and, as a consequence, dredging volume have rapidly increased. Notwithstanding dredging on a nearly daily basis, the ferry link experiences frequent delays during low water, notably during spring tide and wind set-down conditions. Increasing maintenance costs and decreasing time-table reliability have resulted into a study to investigate the causes for this adverse trend.