A Griffith University researcher has brought engineering and ecological science under the one umbrella to reveal that carbon capture is a significant phase in the carbon footprint life cycle of vegetated stormwater systems.
Led by PhD candidate Emad Kavehei, who worked alongside Dr Graham Jenkins from the School of Engineering and Built Environment, Dr Fernanda Adame from Griffith’s Australian Rivers Institute and Professor Charles Lemckert from the Faculty of Science and Technology, University of Canberra, the research offers insights into the carbon footprint of vegetated stormwater infrastructure and appears in the journal Renewable & Sustainable Energy Reviews
Much of what engineers and decision makers understand about the carbon footprint is limited to the four phases of the ‘life cycle assessment’ method. This includes the material production, construction, operation and maintenance, plus the end-of-life phases.
However, with the emergence of green or vegetated alternatives to conventional stormwater infrastructure, these systems are bridging gaps between engineering and ecology to improve sustainability and control the environmental impacts of urban development on the downstream environment.
“What we’ve done in this paper is merge engineering and ecology,” Mr Kavehei said.
“There are already many papers that talk about the benefits of stormwater basins that are vegetated, but in these systems there are also carbon sequestration potentials, and the studies have not examined these benefits and these potentials together.”
The team studied a wide range of vegetation-based stormwater infrastructure including green roofs, bioretention basins, vegetated swales, rain gardens and stormwater ponds.
The findings showed that rain gardens and bioretention systems had the potential to mitigate more than 70% of their total carbon footprint in their 30-year lifetime.
Mr Kavehei said the results were valuable for researchers, designers and policymakers when considering the carbon implications of any potential green stormwater infrastructure and provided materials to estimate the net carbon footprint for vegetated stormwater basins.
“There is conflict because a vegetated system requires more maintenance than a constructed pipeline does, for example,” he said.
“But vegetated systems have the potential to sequester and reduce the carbon emissions and footprint through the whole service years of life cycle in stormwater infrastructure.
“What is important for policymakers and councils is that they can claim these basins are carbon friendly. If they know they can build more of these sites they can claim for carbon reductions, so it would be win-win. They would have a system that treats stormwater and adds environmental benefits to Australia’s goal of reducing carbon emissions.
“From an ecological view, having more of these systems adds to the biodiversity of neighbourhoods, so for example having more vegetated stormwater systems will increase birds and wildlife in these areas.”