Melbourne will suffer more frequent and severe floods as stormwater drains struggle to cope under climate change, according to Victoria University engineers.
Dr Nitin Muttil of the Water Resources Group in the School of Engineering and Science at Victoria University said old drainage infrastructure in many Melbourne suburbs couldn't cope with the intense rainfall that's becoming more frequent.
"The current council infrastructure in many areas can simply not handle what is coming," Dr Muttil said.
Rainfall trends indicate total rainfall in southeast Australia is decreasing, but extreme events are becoming more intense, leading to more frequent and destructive flash floods in recent decades. Recent examples include Melbourne's summertime storms of the last two years, which resulted in widespread flash flooding.
Dr Muttil and his team have entered an agreement with the City of Greater Dandenong to identify and map at-risk areas based on topography, drainage capacity and future rainfall projections for the next 20 - 50 years.
He said other local councils were also interested in the research as a tool to plan upgrades to drainage infrastructure identified as at risk.
Dr Muttil said it was not only climate change but also urban sprawl that was making the city more prone to flooding because rainfall does not seep into the ground in urban areas like it does in rural areas.
"Instead it goes straight into gutters and drainage systems where it travels through catchments many times faster than it would if falling on a rural area," he said. "This leads to more severe flash flooding."
This project is part of ongoing research into the impacts of climate change on urban drainage systems, and rainfall trends and water resource management within the Yarra River catchment.
(note: raindrop image courtesy of Pfly on Flickr)