China has a long tradition of mastering water engineering, yet the systems and standards used today in the form of concrete walls and stone dykes along rivers, and drainage pipes under roads have been failing all too often.
Climate change and climate variability means this “gray infrastructure” may not be able to effectively protect urban areas.
China is looking to harness a “green infrastructure” approach, as well as partnerships on flood risk management covering entire river basins.
In promoting ecological civilization, China recognizes the importance of both green infrastructure and the river-basin-wide approach. Currently a national “Sponge City” program is under way requiring cities to develop sponge city master plans and includes 16 pilot cities. Under this program, a whole city would absorb, harvest, store, filter, purify and slowly release rainwater into rivers and the ground like a sponge does.
Green infrastructure utilizes the capacity of natural systems to manage storm water and reduce flooding. For example, intelligently planned and protected urban green spaces can retain large volumes of storm water that will otherwise flood roads and buildings.
Parks along rivers that are designed to be at a low level relative to the normal water level, and with gentle slopes, will retain water rather than let it run off and cause damage. Depressed parks located strategically to receive floodwater, and green roofs also increase a city’s storm water resilience.
Planned as systems this green infrastructure can significantly reduce the risk of floods and help cities manage water resources in a sustainable way, while making them more green and livable.
These green spaces provide a variety of ecosystem services creating many other benefits, including recreational and community amenities for residents, improved urban microclimate, reduced pollution and better public health. The green open spaces are also a habitat for plant and animal biodiversity, while parks and riverfront greenery boost real estate values.
All this proves green infrastructure is a highly integrated win-win approach to reducing flood risk, especially when the opportunity of newly planned areas allow for integrated green infrastructure planning integration.