Flushing basins have been used at several locations in Germany, Belgium, and the Netherlands in the past centuries to maintain the navigational depths of harbour channels. These locations are not in use anymore or are only partly responsible for channel maintenance. This thesis encompasses a study to optimize the geometric parameters of a flushing basin system in a tidal back barrier basin. The addition of a flushing basin behind a tidal harbour channel is meant to affect the sediment regime in the channel from a flood-dominant towards an ebb-dominant regime. With a one-dimensional model of a schematized reference situation, the role of three parameters: the sluice width, the horizontal area of the flushing basin and the ratio between the tidal amplitude and the channel depth, in the tide-residual sediment transport is investigated for the flushing basin system. Three conditions need to be met simultaneously to create ebb dominance along the total length of the channel: a sufficiently large flushing basin area, a small sluice width, compared to the channel width and a relatively deep channel compared to the tidal amplitude.