Author(s): Jon Barnett (corresponding author) ; Sarah Rogers ; Michael Webber ; Brian Finlayson ; Mark Wang 
Almost one year ago, Beijing began to receive water channelled by the South-to-North Water Diversion (SNWD) project. The biggest inter-basin transfer scheme in the world, the SNWD project has the capacity to deliver 25 billion cubic metres of fresh water per year from the Yangtze River in China's south to the drier north by two routes - each of which covers a distance of more than 1,000 kilometres. The project connects four major river basins, three megacities, six provinces and hundreds of millions of water users and polluters.
Its success is already in question. Reservoir and canal construction costs have reportedly reached US$80 billion, and more than 300,000 people have been displaced . Pollution and environmental fallout, as well as high maintenance costs and water prices, make the project unsustainable both ecologically and socially. And the transfer of water does not address the underlying causes of water shortages in the north, namely pollution and inefficient agricultural, industrial and urban use - the effects of which we have been studying over the past decade.
North China could be self-sufficient in water without the transfer of water from the south. But the necessary steps - among them, improving local pollution monitoring and building better irrigation infrastructure - are inadequately implemented.
Increasing supply is viewed as the main solution to water scarcity because of the conflicting roles of the Chinese government as both entrepreneur and regulator. Incentives for economic growth in China still outweigh incentives for pollution control and limits on water extraction, despite ever stricter environmental laws. Many industries, such as the country's huge hydropower sector, profit from expensive solutions to boosting water supplies.
China's water system needs an overhaul. Institutional reforms must divorce profit motives from regulatory functions; data and decisions must be disclosed to the public; and the influence of the hydropower sector on water-resource management needs to be restricted. The volume of water being diverted along existing routes of the SNWD project must be reduced and extensions to the project must be shelved.
Better local management of resources is the only way to bring secure and sustainable water to all parts of China.
China's history of grand water-engineering projects is almost as old as the nation itself, and is inextricably knit with the country's politics, development and self-image. The first dam was built in around 600 bc at Anfeng Tang in eastern China. It created a still existing reservoir 100 kilometres in circumference that could irrigate an area of 24,000 square kilometres. Ever since, most of China's water-management systems have been created and run by the state.
The SNWD project transports water in two ways (see 'South-to-north water transfer'). Its eastern route has the capacity to supply up to 14.8 billion cubic metres of water per year to the provinces of Jiangsu, Anhui, Shandong and Hebei, and to the city of Tianjin. The water travels through a system of...