On the downstream (eastern) side of Casino, the topography flattens out to form an extensive floodplain.
Under very large flood events, waters break the banks upstream of Casino and bypass the town via a large flow path to the south. The river through Casino is effectively a gorge with high banks, exposed rock beds and river bed levels dropping over 8m through town. While the Richmond Valley has a long history of flooding, the Casino township has only experienced a few major floods over 15.30m where the CBD is affected. Casino sits on the Richmond River and hosts a population of approx.