Assessment of the municipal water cycle in China Tao Wang a,b,c, ⁎, Shuming Liu d , Xuepeng Qian e , Toshiyuki Shimizu a , Sébastien M.R. Dente f , Seiji Hashimoto g , Jun Nakajima g a Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan b Circular Economy Research Institute, Tongji University, Shanghai 200092, China c Institute of Science and Technology for Development of Shandong Province, Shandong Academy of Sciences, 19 Keyuan Road, Jinan 250014, China d School of Environment, Tsinghua University, Beijing 100084, China e Asia Pacific Studies, Ritsumeikan Asia Pacific University, 1-1 Jumonjibaru, Beppu, Oita 874-8577, Japan f Research Organization of Science and Engineering, Ritsumeikan University, Japan g Department of Environmental Systems Engineering, Ritsumeikan University, Japan HIGHLIGHTS • The municipal water cycle was charac- terized for 655 Chinese cities. • In N 100 cities in North China, their mu- nicipal cycle is exposed to water scarcity. • The proposed options may technically se- cure urban water supply toward 2030. • Better efficiency and cost-effectiveness of the municipal system is to be achieved. GRAPHICAL ABSTRACT abstract article info Article history: Received 10 April 2017 Received in revised form 4 July 2017 Accepted 8 July 2017 Available online xxxx Editor: Simon Pollard Water produced from municipal utilities accounts for nearly 10% of the sum water demand in China. The municipal water cycle that integrates processes of urban water supply, water use, sewage treatment, and water reclamation has been assessed for 655 cities across nine drainage areas in mainland China in 2012. These cities in total extracted 55 km 3 raw water for municipal use from surface waterbodies and ground aquifers, approximate to the country- wide freshwater extraction of Russia or Italy. After purification and transmission, 45 km 3 water was distributed to industrial, service, and domestic users. 36 km 3 of post-use sewage was collected and environmentally safely treated; merely 3.2 km 3 of the treated water was reclaimed. Driven by increasing urbanization, the municipal water demand in cities of China may grow 70% by 2030. The Hai River and the Huai River basins, which harbor 137 cities and occupy a majority of the densely populated North China Plain, are most exposed to physical water scarcity. The municipal water abstraction in these cities can remain constant by promoting demand-side and pro- cess conservation in the next two decades. Interbasin transfer and unconventional sources will provide municipal water double than the cities' need. Whereas the urban water security can be technically enhanced, the challenges are to better improve water use efficiency and mitigate economic and environmental costs of the municipal system. © 2017 Elsevier B.V. All rights reserved. Keywords: Municipal water cycle Process water loss Water scarcity Reclaimed water Water efficiency Scenario analysis Science of the Total Environment 607–608 (2017) 761–770 ⁎ Corresponding author at: Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan. E-mail address: a.t.wang@foxmail.com (T. Wang). http://dx.doi.org/10.1016/j.scitotenv.2017.07.072 0048-9697/© 2017 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv