China can show world how to conserve water

Pouring oil on troubled waters - or calming a difficult situation - is an idiom derived from the ancient practice of doing just that to calm turbulent ocean waves. These days it would be denounced as an environmental crime.

This has ironic resonance on the mainland, which depends on oil to fuel its explosive industrial growth, but could do without the calamitous pollution of its dwindling water resources by petroleum byproducts.

China can offer trade, aid and investment to other countries to secure oil supplies. Keeping enough clean water flowing at home is a more troubling problem.

The rain over southern China this week could not drown out fresh alarms about the supply and quality of water. The warnings are not new. That the increasingly grave scenarios are now being painted by officials is what claims attention.

The country's top water-resources official dismissed hopes that the massive Three Gorges Dam and ambitious water-diversion projects will relieve shortages, while state media highlighted frightening assessments of the effect of pollution of the Yangtze River.

What does it all mean? As we report today, for people who want nothing more than water for everyday use, it can mean water, water everywhere and not a drop to drink.