The Border Rivers basin comprises a complex drainage network of some 44,070 square kilometres. The northern half of the basin being located in Queensland and the southern half in New South Wales.

Most headwater streams in the south eastern portion, originating in the New South Wales Great Divide have similar characteristics. They flow through narrow steep mountain valleys to the main river. The north eastern portion in Queensland comprises generally flatter topography. The remainder of the basin is mostly flat to undulating land which can contribute significant runoff.

Flooding in the upper catchment is generally confmed to the main stream areas and adjacent alluvial flats. The elevated surrounding countryside is mostly flood free. The extent of the alluvial flats and hence the overbank flooding increases as one moves down the valley.

Downstream of Boggabilla, a complex network of effluents and anabranches have evolved. These divert water from the main river. During major floods the carrying capacities of the numerous watercourses are not sufficient to confme the flood volumes within the banks. Floodwater begins to flow over most of the floodplain causing inundation of a vast area.

This report is to collate all of the available data on the recent January 1996 floods for the Border Rivers system.