The ever-changing erratic nature of our climate and the increasing hard surfacing within the urban environment, including urban creep. Blue-green drainage infrastructure (BGI) is becoming a vital part of cities as it integrates sustainable water management with urban planning.

By mimicking natural ecosystems, BGI addresses challenges like urban flooding, water and air pollution, and heat islands. Features such as permeable surfaces and revitalised rivers improve stormwater absorption and quality while creating habitats for biodiversity. These systems enhance public spaces, making cities more liveable and resilient to climate change. Additionally, they foster community engagement and well-being, promoting sustainable development.

The Hong Kong Drainage Services Department (DSD) promotes BGI, blending water management and green spaces to create sponge-like urban systems. Their approach includes reinstating rivers and greening drainage facilities, thus enhancing their local biodiversity and subsequently improving ecosystems, holistically supporting the urban living experience.

Landmark projects, such as the Kai Tak River revitalisation, demonstrate how functional drainage systems can double as ecological and recreational spaces. Initiatives like roof greening and community-inclusive designs further integrate sustainability into infrastructure, fostering environmental stewardship and public engagement.

Retrofitting is being implemented in other cities, like Sheffield and Cardiff, but these projects are small and come with many constraints. Needless to say, to avoid more catastrophic flooding situations more needs to be done.

http://www.dsd.gov.hk/EN/Publicity_and_Publications/Publicity/DSD_Sustainability_Reports/20/blue-green_drainage_infrastructure.html