The world’s largest dam is under pressure in the massive flooding that’s wiping away billions of dollars of value in China. The predicament symbolizes a looming crisis for Beijing. Climate change is bringing more frequent and intense deluges that threaten the economic heartland, and infrastructure defenses installed with the disasters of previous eras in mind can’t keep up. There’s very little time to prepare for what’s coming.

The problem isn’t that China lacks water management projects. It has built hundreds of thousands of levees, dikes, reservoirs and dams on its seven major river systems. But many are struggling to cope with months of rain-fed flooding that has ravaged vast swathes of industrial and agricultural land and engulfed millions of homes. This past week, officials feared that the Three Gorges Dam on the mighty Yangtze was peaking and could overflow. Elsewhere, authorities have blown up barriers that were causing more damage than help.

China has experienced three of the world’s 10 most devastating floods since 1950. The limited number of deaths this time is a testament to how far the country has come, with officials saying that at least 219 people have died or disappeared. Yet flooding in cities is getting worse, a sign of rising populations and failure to execute urbanization policies.