The stretches of coasts near tidal inlets are often very dynamic. This is the result of a complicated sediment transport pattern induced by tidal and wave driven currents. Sediments from the one side are imported into the tidal basin or are bypassed along the tidal bars, whereas the other side may receive sediments exported from the tidal basin or from direct bypass (see Sect. 9.4.2). The position of the main channel system may oscillate or gradually shift in a specific direction due to the accumulation of sediments at one side of the inlet and erosion on the other side of the inlet. This may eventually lead to spit formation (cf. Fig. 8.28). The dynamic behaviour often hampers safe navigation and may cause damage to the properties adjacent of the inlet. The inlet may act as a sediment sink for longshore sediment transport, therewith depriving the downdrift coastline from sediment.