The flooding that hit Beijing a week ago (above) was a freak. The rains that caused it were the heaviest in 60 years. Severe weather, certainly, but not beyond the bounds of what a national capital should be prepared to deal with. And certainly not with as heavy a loss of life, 77 dead. It has revealed weaknesses in urban planning, construction, infrastructure and emergency management. “We must seriously reflect on these lessons and always bear them in mind,” Guo Jinlong, Party boss in the city, says. Quite.
Urban flooding is a worsening problem in China (and elsewhere) as global warming, urbanization and industrialization pose a growing triple threat to cities’ natural defences, especially those of cities in developing economies. But beyond the human costs are the economic disruption as transportation, communications networks and electricity supplies, the arteries of modern cities, are put at risk of seizing up. Authorities’s preliminary estimate of the economic cost of the recent floods in Beijing is 2.26 billion yuan ($360 million).
Over the past 30 years, floods have been getting bigger and more frequent around the world but no region has been more affected than the Asia-Pacific and no country in the region more than China. (A list of Asia’s worst floods since 2000 is here.) More than 100 million Chinese have moved from inland areas to flood-prone coastal cities in the past quarter of a century. Yet China has only recently started to shift its emphasis from reacting to urban flooding to preventing it, and, as it happens, at about the same stage in its development as Japan started to do three decades ago. Taiwan and South Korea have also since followed suit.
Floods in cities are both more costly and difficult to manage than those in the countryside. Building adequate main sewers and storm water drains to manage urban rainwater is straightforward enough in greenfield developments. The difficulties lie with older built-up areas. There sewers and storm drains are often old and inadequate, run-offs from hard surfaces absent, ground storage for rainwater scarce and ancient streams that could carry rainwater to rivers and ponds that could help it find its way to acquirers below, filled in. An irony of the Beijing floods is that the aquifer below the city is drier than ever. Redressing these problems are huge engineering tasks that cities cannot complete overnight. But starts have to be made. Beyond that are longer-term policy issues of not allowing development in flood-prone areas, giving local districts within cities the information to make their own local anti-flooding preparations, and making cities greener so they are less encouraging to extreme weather.
From 2011 to 2020, China’s investment in water conservancy projects, including flood defenses, is expected to reach 4 trillion yuan ($617 billion), almost four times as much as that spent during the previous 10 years. Yet nature has provided lakes and floodplains to do the same job. An important part of fighting floods, and one of China’s other perpetual natural disasters, drought, is the protection, restoration and reconnection of lakes, ponds, streams and floodplains so they can do what they do best: take in water when the river is high and give it back when it is low. Rivers and lakes cannot be infinitely sacrificed or bent to man’s will in the name of economic development. Urban planners have only just started to apply the lessons of that. China’s developers will have to be made to, too.