17.5 Overbank flood spilling

Supporting information

This process occurs in the Canberra region, but the volume could not be quantified due to the lack of both data and a suitable quantification approach.

Minor to moderate flooding occurred within the Canberra region and it caused to evacuate the community around Queanbeyan at the beginning of March 2012 (The Bureau of Meteorology 2012, Special Climate Statement 39).

Despite the overbank flood spilling and return to river channel being significant in volume during these floods, the volume was not able to be quantified. However, as neither the overbank flood spilling nor return to river channel could be quantified, the impact upon the surface water store in the water accounting statements would not have been as pronounced. Although some flood waters would have replenished groundwater within the region and evaporation or other losses to flood waters would have occurred, most of the overbank flood spilling would have returned back to the river channels. The natural topography of the Canberra region would result in all the flood waters within the Queanbeyan flood plains returning to the river channel prior to flowing out of the Canberra region.