By author Prof. Asik K. Biswas and Cecilia Tortajada
More than a decade ago, China decided to take a long hard look at the way it managed it water resources. Its aim was to put an end to the devastating floods and pollution that had long blighted the country and held back its economic development.
The result has been nothing short of revolutionary. In just 15 years, China has gone from being behind the curve to a world leader in in water-related technology and regulatory oversight.
Rapid urbanisation had steadily reduced the land in cities which could absorb rainwater, not least through the filling up of wetlands and lakes. Impermeable construction materials exacerbated the problem, leading to a series of severe urban floods. China’s response was both ambitious and innovative – sponge cities.
The rollout of ‘sponge city’ technology to China’s metropolises reduces rainwater runoff by expanding and enhancing the absorption capacity of urban areas. This not only helps reduce flooding but also contributes to water security. An additional benefit of sponge city expansion is the cooling of temperatures in China’s urban districts.
With sponge cities, the goal is to ensure 80 per cent of China’s urban areas will absorb and reuse at least 70 per cent of rainwater, at an estimated cost of CNY 1.6 trillion.
New cities are being planned, and existing ones will be expanded. Each will feature artificial and scenic wetlands for rainwater storage, rooftop gardens in buildings, permeable pavements than can effectively percolate and store rainwater, and rain gardens where people of all ages can interact with nature.
Sponge city projects in Wuhan, Xiamen, Lingang and Suining have already performed well during heavy rainfalls.
Chinese companies have made remarkable advances in robotics, artificial intelligence and big data analytics. And many have deployed such technologies to good effect in the water industry. One of the most successful is Dadu River Hydropower Development Company of Chengdu, which is probably 10 years ahead of any other public or private sector company anywhere in the world.
Technology is important, but clearly setting out the responsibility for water management has also played a major part in driving China’s progress. A key part of that is the river chief system.