Hong Kong’s Drainage Services Department (DSD) is actively revitalizing water bodies across the city Click & Tweet! with priority given to greening, biodiversity and aesthetic improvements in addition to ensuring effective drainage.
With Blue-Green Infrastructure – blue refers to rivers and water bodies while green refers to greening landscapes – DSD aims to provide citizens with rivers suffused with lush greenery and pristine blue, so as to offer more opportunities for the citizens to get closer to water bodies and participate in healthy activities including strolling, jogging and cycling.
In addition to beautifying Hong Kong, the motivations for implementing Blue-Green Infrastructure is to reverse or mitigate the challenges that both urbanization and climate change pose to Hong Kong.
Challenges to water in Hong Kong
The urban area of Hong Kong has the highest population density in the world. Measured at the block level, some areas have population densities of more than 400,000 people per square kilometer. At the same time, Hong Kong, with up to 3,000 millimeters of annual rainfall, is one of the wettest cities in the Asia-Pacific region, making both people and infrastructure vulnerable to flooding from climate change extreme weather events.
Some of the key impacts of urbanization and climate change events on Hong Kong’s water include:
- Water quantity impacts with increased flow from surface runoff
- Water quality impacts of increased surface runoff from impervious areas (roads, roofs etc.) along with stormwater overflows contaminating waterways
- Increased flooding risks from waterways being straightened
- Decreased habitat for wildlife
A Blue and Green Hong Kong
To reverse the impacts of urbanization and reduce risks from flooding events, DSD is undertaking several Blue-Green Infrastructure projects that will provide numerous environmental as well as social benefits to Hong Kong residents.
Kai Tak River Improvement Works Initiative
One of the main projects underway is the Kai Tak River Improvement Works Initiative that in addition to upgrading drainage capacities is being injected with aesthetic, greening, landscaping and ecological elements, thus revitalizing the ‘nullah’ into an “urban green river along a serene emerald corridor”. To improve biodiversity and microhabitats, the project will involve installing fish shelters, current deflectors and boulders in the riverbed. In addition, the banks of the waterway will be lined with faux rocks and different types of plants to accentuate the greening effect.
Blue-Green Infrastructure in the Anderson Road Quarry Development
Over the past year, DSD worked with the Civil Engineering and Development Department and the Leisure and Cultural Services Department to build a flood retention lake in the plan of the Anderson Road Quarry Development. The project will serve to reduce flood risk in East Kowloon and provide a scenic waterscape environment for residents. The design will also feature environmentally-friendly drainage designs including permeable pavements Click & Tweet! , rainwater harvesting facilities and infiltration planters.
Energizing Kowloon East Initiative
DSD is undertaking the Energizing Kowloon East Initiative in which a nullah approximately 1 kilometer-long will be converted into ‘Tsui Ping River’. As part of the theme, adjacent pedestrian paths will be beautified, improving connectivity between pavements through the building of riverside walkways and landscape decking.
Blue-Green Infrastructure enables cities to simultaneously reduce the impacts of urbanization while mitigating climate change risks.
*Robert C. Brears is the author of Urban Water Security (Wiley), and of the forthcoming titles Blue and Green Cities (Palgrave Macmillan) and The Green Economy and the Water-Energy-Food Nexus (Palgrave Macmillan). He is Founder of Mitidaption, which consults on climate change risks to business, governance and society.