Drains to rein in rain

Has rainwater drainage system received enough attention in our urbanization drive over the past few decades?

Urban planners need to reflect on the question especially after the heaviest rainstorm in 61 years devastated Beijing on Saturday. Similar rainstorms have caused trouble in a number of other cities, including Nanjing, Hefei, Wuhan and Chengdu lately. In fact, a torrential downpour, even if it is not the heaviest in decades, can paralyze traffic in many Chinese cities.

Beijing authorities have admitted that the capital's drainage system leaves much to be desired. It could drain out rainwater only if precipitation is 30 millimeters or less an hour. That is also true of most cities across the country.

Beijing will gradually improve its drainage system and upgrade the pumping stations to drain out rainwater from under its underpasses in urban districts before 2015, after which even a precipitation of 60 millimeters an hour is unlikely to cause inundation. Apparently, many cities will have to do the same.

Saturday's deluge in Beijing has led to 37 deaths and an estimated economic loss of 10 billion yuan ($1.56 billion). These losses could have been avoided had the capital done a better job of its drainage system during its urbanization drive over the past decades.

China's urbanization process is far from over, and many prefecture- and county-level cities are yet to start large-scale construction or are in the middle of their urbanization drive.

The embarrassment many big cities face because of rainstorms should remind planners to pay adequate attention to the designing and building of a foolproof drainage system. Futuristic buildings and wide streets can be enjoyed only if they are supported by a sound utility system, which includes large sewers and efficient pumping stations.

If a sound drainage system is built in advance, the cost would undoubtedly be lower than when it needs to be upgraded or rebuilt after a city has completed its urbanization drive above ground. But for that urban planners need to have a broad vision for future development.

Most big cities, including Beijing and some provincial capitals, can improve their drainage systems only by pumping in extra-budgetary funds. Hopefully, urban planners in other cities will learn from the big cities' mistakes and do a better job of dealing with the rain.

(China Daily 07/24/2012 page8)