We disagree with Jon Barnett and colleagues that China's South-to-North Water Diversion (SNWD) project marks a low point for big engineering solutions to the country's water problems (Nature 527, 295–297; 2015). The SNWD conveyed 8.37 billion cubic metres of water (6.20 billion by the eastern route; 2.17 billion by the central route) to millions of people in northern China by the end of 2015. It is also acting as a buffer against imminent ecological disaster and social upheaval.

It will take time to educate the public about water consumption and to implement the reforms to agricultural and industrial production that the authors propose. The 'sponge city' programme to harvest rainwater and recycle wastewater is also likely to be costly and disruptive. Meanwhile, the SNWD is providing the material foundations necessary for well coordinated water management.