Plan puts floods to good use
AS 100-year floods become more common, blue-green infrastructure could reduce the impact of flooding on our environment and economy.
The aftermath of floods can have devastating and farreaching effects.
In 2017, Deakin University research, funded by the Bushfire and Natural Hazard Cooperative Research Centre, found that a state that experienced a flood in a given year, on average, achieved 4.5 per cent lower agricultural production in the following two years, compared with a state that did not have one.
Now, research from Deakin’s Centre for Regional and Rural Futures proposes a way to mitigate the negative environmental and economic effects of flood, while making it possible to benefit from the positives, such as increased soil fertility and biodiversity, and recharged groundwater.
Blue-green infrastructure is an interconnected network of natural and semi-natural landscape components, including water bodies and open spaces, which have multiple functions, such as water storage for irrigation or water purification.
It can be applied in rural and urban areas and river catchments and is significantly different to conventional infrastructure for preventing floods, such as levees.
The concept has been successfully implemented in a number of countries, including Japan and the US, as the most effective solution to mitigate the effects of climate change and flooding.
CeRRF PhD student and civil engineer Zahra Ghofrani believes it could be particularly useful in Australia’s climatic conditions of intense rainfall and drought.
“Australia faces a variety of natural disasters, but research shows that flooding is the most destructive and most costly,” Ms Ghofrani said.
“Floods can’t be prevented, but we can do something to protect the environment, people and infrastructure.”
Working with local government in South Gippsland, she hopes to examine the feasibility of implementing BGI in the area.
“By focusing on the costs and benefits in terms of biophysical environment, socioeconomic systems and infrastructure, BGI could increase the resilience and sus- tainability of regional and rural Australia,” she said.
South Gippsland’s ageing levees were not designed to face the increased volume and frequency of floods happening under climate change.
“The area has experienced destructive floods, with the most significant occurring in 2007 and 2012. The levees are effective for small floods, but they are often overtopped by larger, more destructive floods,” she said.
For her research, Ms Ghofrani compared the costs and benefits of upgrading the levee system to implementing BGI in the region.
“Reconstructing the levees would be more expensive, have a negative impact on the environment and can be used for only one purpose — to prevent floods, or mitigate their impact,” she said.
“BGI can provide multiple functions, from flood mitigation, to water storage, to protecting native vegetation and wetlands.
“BGI is an integral component of sustainable development and an example of how working with nature, instead of against it, can maximise the benefits of flood and stormwater, while minimising the negative impact.”
Ms Ghofrani, who is in the final stages of completing her PhD, hopes her research will lead to BGI being implemented in Gippsland and other parts of Australia.
“I live in Geelong, and I witness how heavy rainfall causes flash flooding and damages main roads and buildings every year,” she said.
“I hope sustainable solutions such as BGI can be implemented to mitigate the effects of climate change in the Geelong region, as well as other parts of Australia.
“Once we show people it can work as a real application in their community, I hope to drive implementation projects that could save regional communities from the damage associated with the next major flood.”