The relatively small Keurbooms/Bitou estuarine system on the south coast of South Africa forms a typical bar-built estuary, with a back-barrier lagoon and a barrier dune almost 4-km long. The lagoon is only about 500-m wide, while the barrier dune is not anchored to any substrate and consequently the position of the tidal inlet, or mouth, varies over the whole length of the barrier dune. This study analyses the sedimentary morphology over the years 2006-2019, during which time, three flood events caused substantial changes in the position of the mouth and the structure of the flood-tidal deltas and flow channels. It is found that after each flood the tidal exchanges reached a maximum, decreasing as sand entered the estuary again. The floods caused considerable infrastructural damage, and the sedimentary changes affected the tourism industry which is dependent on stable tourism attractions in the area. With no management changes, it is surmised that future floods will continue the process of dramatic changes in morphology of the estuary, though climate change may exacerbate these effects.
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