A rainstorm caused chaos in Beijing on June 23 paralyzing the city's traffic and turning the city's underpasses into treacherous hazards for drivers.

In the wake of the torrential rains that have hit the city this summer the municipal authority indicated on July 18 that the drainage systems of all underpasses in Beijing will be improved and underground catchment facilities will be constructed to collect rainwater.

Water is an extremely precious resource for Beijing, and this is an applaudable change of mindset by the authorities who used to regard rainwater as wastewater destined for the sewers.

The population in Beijing reached 19.61 million this year, hitting the 18 million mark 10 years earlier than the development plan drawn up in 2005 predicted. The fresh water per capita in the city has now shrunk to 100 cubic meters, one-tenth the international standard, making it one of the thirstiest cities on earth.

Rainwater conservation has become a hot topic for cities around the world and the longest waiting list in New York is for rainwater barrels. The city handed out 1,000 free barrels to water-conscious residents in April.

In Tokyo the capacity of the drainage system can be adjusted to collect as much water as possible and the green areas of the city are designed nearly 1 meter lower than the surrounding asphalt and concrete surfaces in order to let rainwater recharge the city's groundwater.