Water-saving strategies across prefectures should target the manufacturing and agriculture sectors in China

Water scarcity is a global challenge in many emerging economies, including China. China is one of the most extensive freshwater users and has set water efficiency improvement goals for 2030 at the prefecture level. However, no systematic water use and savings comparison exists across prefectures and sectors. Here, we used datasets of water withdrawal for 10,608 industrial and 1715 agricultural sub-sectors for 343 prefectures, and explored the opportunities to reduce water use. Results show that 10% of the least water-efficient industrial sub-sectors represent a disproportionate 46% water use. 18.9 km³ (±3.2%) water saving in industry and 50.3 km³ (±2.3%) in agriculture could be achieved, equivalent to Russia’s annual demand. A minority of sectors, including cloth(ing)- and chemical-manufacturing, rice-, vegetable- and fruit-cultivation, could contribute the most to water savings. Our study is essential for identifying water use and efficiency information for individual prefectures and sectors.