We would like to share the story of how local citizens have helped to clean up polluted rivers in Zhejiang province in China.

Three years ago, the regional government allocated 140 billion yuan (US$21.5 billion) to the clean-up operation. It launched a campaign to alert the local population of 55 million to the severity of the pollution and the risk to public health, and to publicize its plans and the benefits in the long term. As a result, Zhejiang citizens support the project and voluntarily cooperate to implement it.

Individual rivers are overseen by a government official and a technology expert, whose contact details are posted at the riverside so that the public can promptly report illegal polluted discharges from factories and other sources. The officers then order these discharges to be cut off, knowing that their own promotion depends on swift action and improvements in water quality.

This overall strategy has markedly increased urban water quality (go.nature.com/292hwbi; in Chinese). It has also enabled the government to economize on monitoring equipment.