For visitors, China’s water problem becomes apparent upon entering the hotel room. The smell of a polluted river might emanate from the showerhead. Need to quench your thirst? The drip from the tap is rarely potable. Can you trust the bottled water? Many Chinese don’t. What about brushing your teeth?

Measured by the government’s own standards, more than half of the country’s largest lakes and reservoirs were so contaminated in 2011 that they were unsuitable for human consumption. China’s more than 4,700 underground water-quality testing stations show that nearly three-fifths of all water supplies are “relatively bad” or worse. Roughly half of rural residents lack access to drinking water that meets international standards.

For all of the dazzling progress that the world has come to associate with a booming 21st century China, the quality of its water supply has failed to keep up with the country’s leap into modernity.

Policy makers and the Chinese public rightfully blame lax environmental controls and shoddy enforcement. But the more fundamental problem is that the country simply doesn’t have enough water. Breakneck and large-scale industrialization has overwhelmed scarce supplies — and drinking water has become one of the most visible casualties.