Nature

South-to-north water transfer: “The costs hardly add up”

China’s plan to divert water from its southern regions along thousands of kilometres of canals to the arid north has been dubbed “a dream to be realised” by Chinese state media. S.C. Warren assesses the need for the project and explains his reservations.

The need for a response to China’s water shortage is not contested. China is one of the most water-poor countries in the world, languishing at number 122 in the worldwater league table below other populous nations, including the US and Russia.

Supply in the northern regions is especially tight. Just one quarter of China’s total annual rainfall falls on the barren landscape that stretches from Beijing to Gansu province, and water tables have dropped sharply in recent years as farmers bore further into the earth’s crust to extract water for their crops. A projected 25% growth in the national population over the next 30 years will not make life any easier. Meanwhile, some areas in the south suffer from the opposite problem – an excess of water – as a result of seasonal flooding.

Ningxia Hui Autonomous Region, a dust-bath on the fringes of the enormous Loess Plateau, is on the front-line of China’s water struggles and is already classified as water-short by international standards. Migration from the region is the solution, according to provincial governors, who believe that having fewer people will ease the crisis. Even so, supply is predicted to drop by almost half by 2030 as consumption rates increase.

In the long-term, Ningxia is also one of the proposed beneficiaries of the south-to-north transfer, which aims to correct regional supply imbalances through the construction of three canals – eastern, central and western – stretching over 3,000 kilometres to create a basin-to-basin transfer from the southern Yangtze to the northern Yellow River.

Sceptics have questioned the wisdom of the scheme. Work is due to involve the displacement of hundreds of thousands of people, engineering work on a colossal scale and fundamental changes to the hydrological and ecological functioning of the two river systems. The price-tag, estimated to reach as much as US$ 59 billion by the project’s completion in 2050, is also gargantuan. But is it money well spent?

Agriculture, which stands to benefit most from the water transfer, is the major problem. Grain and other crops guzzle an enormous 70% share of China’s total water availability, but contribute just 15% in return to China’s GDP earnings. Based on current land-use patterns, therefore, the cost of providing water through any component of the south–north transfer scheme would make its use for irrigation uneconomic, even if grain prices trebled.

Once less tangible costs associated with the transfer schemes are taken into account – the disruption of hydrological and ecological processes, loss of wildlife and landscapes – the lack of economic justification becomes even clearer. Even higher economic returns from industrial and urban users on some routes do not balance the books.

Low levels of efficiency in water use raise yet further question-marks over the need for massive new infrastructure.

Better irrigation systems, for example, could achieve significant reductions in overall use. Efforts to renew creaky infrastructure, especially pipes, could also cut wastage, which could run as high as 50%, according to unofficial estimates.

Investment in wastewater plants that allow water to be recycled provides yet another alternative. Water taken from the River Thames in England, for example, is used at least three times before it enters the sea some 200 km from its source. Despite its high level of re-use, the Thames remains of relatively high environmental quality due to careful recycling.

Better pricing, too, would play its part. In the former Soviet bloc countries of central Europe, domestic water use fell by almost 50% following relatively straight-forward price increases. Despite a new water law in 2002 that commits the government to price reform, water in China remains hugely under-priced, meaning that there is no incentive to be more sparing.

Whereas the transfer scheme provides up to 44.8 billion m3 of additional water to the Yellow River each year, management fixes (with the necessary political will) and gradual restructuring of the Chinese economy could more than double this amount.

 

 

Key recommendations of Dr. Warren’s report:

1. Reduce leakage from urban distribution systems;
2. Improve the collection and treatment of waste water so that it can be re-used downstream;
3. Discourage irrigated agriculture in arid regions;Improve irrigation methods and practice;
4. Improve irrigation methods and practice;
5. Encourage grain exports from regions of the country where crops are at least partly rain fed

 

The above extract was adapted from a WWF-commissioned report, “The proposed South–North Water Transfer Scheme in China: Need, Justification and Cost”, which was written in 2001. WWF China wishes to make it clear that the views expressed are only those of the author, Dr. S.C. Warren.

Homepage photo by Sam Haldane