XIANGYANG, China – This factory located in a quiet island of central China’s Xiangyang city probably won’t grab your attention. Its stainless steel complex and three-story office building look similar to any other. But don’t be fooled by appearances. The plant here holds a secret that has lured more than 100 Chinese mayors to pay their respects and uncover how they can replicate its success.

Shenzhen sits in subtropical south China, where four-fifths of the country’s water resources flow. The monsoon brings heavy rains from April to September; at its peak, Shenzhen’s more than 7 million residents see pouring rain almost every day. So why is this city facing a serious water shortage?