Why the technical efficacy of green infrastructure alone is not enough to promote its widespread uptake to manage urban floods

Urban flooding due to unsustainable stormwater management infrastructure is one of the most pressing challenges being faced today. It is mainly caused by increased stormwater runoff from impervious surfaces which, in turn, is a consequence of rapid urbanisation, natural land cover degradation, and climate-change related increases in the frequency and intensity of rainfall.

Green infrastructure (GI), also known as nature-based infrastructure, has been recognised as a promising solution to manage urban flooding as it mimics the natural hydrological system. However, despite the growing body of evidence that proves its technical efficacy, GI is yet to be implemented as a core flood management strategy because implementers need a greater understanding of the human elements within the broader socio-ecological-technical system.

A systematic review, Knowledge, attitudes, intentions, and behavior related to green infrastructure for flood management: A systematic literature review, published in 2020 evaluated 85 studies to synthesise evidence on knowledge, attitudes, intentions, and behaviours relating to GI for urban flood management. It outlined ways to better incorporate social considerations into ecological and engineering designs to ensure GI interventions are equitable, inclusive and sustainable.

The review found that:

  • Overall public knowledge and awareness about GI and its functionality were low potentially due to the absence of a consistent definition of GI. However, instead of developing narrower definitions of GI, establishing broader public knowledge about nature-based solutions and their multiple functions and co-benefits through awareness-generation campaigns was found to be more beneficial.
  • There was a lack of awareness and expertise about GI for flood management among engineers thus affecting the ability to design it relative to existing grey infrastructure.
  • A wide range of attitudes towards GI’s value was observed due to the presence of different context-specific factors, like home ownership and income level, among the public (e.g., some communities valued landscape aesthetics more than GI’s function in flood mitigation).
  • Willingness to implement or pay for GI varied considerably and were deemed to be related to the poor understanding of GI and lack of trust in institutions.
  • Differences in access to resources and equity between privileged and under-served communities remain important and underexplored areas with regard to GI. Policy initiatives should therefore involve inclusive and representative engagement with communities to lead to truly sustainable GI programs.
  • Support from local authorities to implement GI, collaboration between government departments, and clarification of responsibilities are all crucial to the successful implementation of GI.

The review highlights that the technical efficacy of GI alone will not be sufficient for its widespread uptake due to the wide range of knowledge, attitudes, intentions and behaviours related to GI systems. Policy makers are therefore encouraged to prioritise the social dimensions of socio-ecological-technical systems to help achieve widespread adoption of GI for flood management that is equitable, inclusive and sustainable.

Written by Diki Tsering

The MSDI Evidence Review Service collaborates with McMaster University in Canada to curate the Social Systems Evidence, a freely accessible database of research evidence mapped to all of the Sustainable Development Goals.

Find other reviews in the Social Systems Evidence