In the past, our built environments have relied on measures such as building levees, walls and dams and straightening and lining rivers with concrete, referred to as grey infrastructure, to prevent flooding. Grey infrastructure has proven to be effective in handling flood conditions when the volume of water can be anticipated. However, when uncertainty is encountered, and precipitation occurs outside of historical norms, these systems have proven woefully inadequate in protecting communities.
Another issue in urban areas is the dominance of hard surfaces, resulting in precipitation running rapidly into stormwater systems. As climate patterns shift, the volume of water that must be transported and treated by these systems is increasingly overwhelming those facilities. Furthermore, rainfall in such volumes is less able to infiltrate aquifers and recharge groundwater supplies, exacerbating diminishing groundwater sources and impacting dependent ecosystems and communities.
Meeting these evolving water-in-the-built environment challenges requires us to create a new breed of nature-based and ‘blue-green’ solutions. These solutions can be incorporated into traditional grey infrastructure, or even replace entirely, to enhance protection from flooding; increase aquifer recharge; reduce runoff; lessen impacts on treatment facilities; and mitigate coastal storm surges. These new approaches can also reduce overall water use in a community, limit urban heat islands, and increase adaptive capacity.
One example of this paradigm shift is Fishermans Bend, located in Melbourne, Australia – and the largest urban renewal project ever attempted in the Southern Hemisphere. The area is prone to flooding due to the proximity of the Yarra River and was previously home to polluting industries. Plans for the new 430-hectare site include many innovative blue-green infrastructure components and other technologies to reduce flooding and urban heat island effects while ensuring the community’s access to water. This is done by including smart rainwater tanks, constructing green stormwater infrastructure to store flood waters, building a first-of-its-kind water recycling plant, and incorporating green roofs and walls.
Fishermans Bend provides a blueprint for others to follow globally using nature-based solutions and emerging technology to create a unique, sustainable community that increases biodiversity by protecting and improving the surrounding environments. This community has shown how to shift the risk from flooding, extreme precipitation events and the threat of water scarcity into a benefit through a new, integrated approach to urban design.