Floods from ex-Cyclone Debbie highlight need for natural resilience
On March 28 2017, Tropical Cyclone Debbie hit the central Queensland coast, where it had a significant impact on communities and infrastructure. As it continued south, weakening to a tropical low, it brought significant flooding to South East Queensland and the Northern Rivers, with catastrophic consequences from the 30 March 2017.
The tragic loss of life and property resulting from these floods again highlighted the need to continue building resilience into the landscape, so that our waterways can better withstand times of stress and increased flow, keeping our environment healthier and protecting public and private infrastructure.
As an organisation dedicated to improving the condition of South East Queensland's waterways and landscapes, Healthy Land and Water set about assessing the condition of our various project sites once the flood waters had receded, and we were pleased to note that many of them performed well.
Projects that prevented the kind of severe channel erosion and bank collapse that occurred in previous floods included revegetating creek banks with native grasses, installing flow reduction devices and reinforcing creek banks with rock chutes and other natural infrastructure.
At Laidley Creek near Mulgowie in the Lockyer Valley, a Healthy Land and Water project helped prevent the same level of erosion that occurred during the 2013 floods, when neighbouring farms lost vast amounts of valuable top soil to flood waters.
Similarly in the Upper Warrill Creek, the Engineered Log Jam project reduced water flow and strengthened creek banks which protected the integrity of waterways as flood waters rose. This limited the collapse of stream banks and also reduced the amount of sediment pollution flowing into the Bremer River and ultimately out to Moreton Bay.
Sadly, areas adjacent to our project sites, which had not been worked on and had insufficient good quality riparian vegetation, suffered extensive damage and in some cases collapsed completely, further illustrating the benefits of maintaining strong natural infrastructure.
While damage to waterways and sediment pollution remain huge challenges for South East Queensland, projects such as these are helping to protect our world-class natural assets for the benefit of communities, businesses and the environment.