IN A small ceremony in April this year, a bottle of water filled at Danjiangkou reservoir in central China was presented to the vice-mayor of Beijing. The water had come more than 1200 kilometres. Its arrival signified the start of what China claims is the biggest engineering project of all time. It will divert part of the flow of the world鈥檚 fourth-biggest river, the Yangtze in southern China, to replenish the Yellow river in the north, which is being drained dry.
The first water from the $60 billion scheme should be flowing by the time Beijing hosts the Olympic games in 2008. And around 20 years from now, when the project is complete, it will be siphoning north around 50 cubic kilometres of water a year, which is three times as much water as England and Wales consume in the same time.
The implications are immense. Till now, the world has built its cities close to big rivers, where the water is. Even modern superdams do little more than move water within river basins, holding seasonal floods up in the mountains and releasing them downstream in the dry season. All that is about to change. As well as the Chinese scheme, megaprojects are being planned for the forests of central Africa, the mountains of Spain, the parched plains of India, and maybe soon in the Australian outback and the icy torrents of northern Canada, too. They will replumb the planet to take water to where the people are.
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China鈥檚 鈥渟outh-to-north鈥� project follows hot on the heels of the Three Gorges dam on the Yangtze, the world鈥檚 largest hydroelectric dam, whose reservoir began filling in April. Suddenly, the Three Gorges project seems like little more than a warm-up act for the south-to-north project, whose three stages will each match the Three Gorges for size and cost.
The eastern arm of the new project will extract water from Jiangdu, near the mouth of the Yangtze. From there it will be carried along the 1500-year-old Grand Canal, which today is a foul-smelling sump for China鈥檚 industrial waste, and under the Yellow river, to the water-starved city of Tianjin. The middle arm will begin at Danjiangkou, which will be enlarged 鈥� displacing 250,000 people 鈥� and flow down a new canal as long as France, to Beijing. Work on both these arms begins this year.
The third, western, arm is the biggest and most complex. It will capture the headwaters of the Yangtze in a 300-metre-high dam downstream from the melting glaciers of Tibet. Every year, it will lift a volume of water equivalent to a quarter of the annual flow of the river Nile through a 100-kilometre tunnel into the upper reaches of the Yellow river. Construction is due to start around 2010.
China is suffering a hydrological crisis that leaves it no choice but to embark on such breathtaking projects, says Wang Hao of the China Institute of Water Resources. Five times in the past decade, the 4800-kilometre-long Yellow river has failed to reach the sea for part of the year because every last drop has been diverted to irrigation channels and city taps. Parts of the river鈥檚 parched upper basin are turning to desert, unleashing dust storms that occasionally reach all the way to Canada. This April, as the growing season began, the river had its lowest spring flow for 50 years and irrigation channels dried up across 16 million hectares of fields.
Farmers and cities alike have turned to ancient reserves of underground water, but that is running out, too. Rain cannot replenish it quickly enough, and the aquifers of northern China are being depleted by a staggering 30 cubic kilometres a year. In places, 90 per cent of the reserve is gone. The water table beneath Beijing has fallen 59 metres in the past 40 years. The north of China, which has two-thirds of the crop land but only one-fifth of the nation鈥檚 water, needs 28 cubic kilometres more water each year. That figure will rise to 66 cubic kilometres by 2030, says Wang. So even after completion of the south-to-north scheme, the region will still be short of 16 cubic kilometres a year. The shortfall would be made up with more efficient irrigation, says Wang.
Things could not be more different in southern China. Dominated by the Yangtze, it has four-fifths of the country鈥檚 water but only a third of its fields. Most of the Yangtze鈥檚 flow pours into the sea or overflows its banks. In July 1998, Yangtze floods killed 3000 people. A quarter of a billion people fled its waters in what was probably the largest human evacuation in history. What then could make more sense than to pipe its excess water north?
Yet as vast as the south-to-north project is, by the time it is watering Beijing it may have been upstaged by India鈥檚 efforts. Later this year, the Indian government expects to unveil its river-linking project. The plan is to build dams and canals to link 14 rivers that drain the Himalayas, including the subcontinent鈥檚 two biggest rivers, the Ganges and Brahmaputra. Their waters will pour south along a thousand kilometres of canals, aqueducts and tunnels to fill a second network, comprising 17 major rivers of the country鈥檚 arid south and east (New Scientist, 1 March, page 4).
In terms of the volume of water to be moved it will be similar to China鈥檚 scheme. But the price tag will be two to three times as high: official estimates put it between $112 and $200 billion, or around 40 per cent of the country鈥檚 GDP. The scheme has been a pipe dream of engineers for many years, and gained political momentum last summer when drought hit much of southern India. The spectre of famine returned after a decade in which India had food to spare. By mid-century, India will have to feed an extra half-billion people says Suresh Prabhu, chairman of the newly created task force charged with making the scheme happen. Prabhu admits that China鈥檚 plans are his inspiration.
So within the next decade or so, the world鈥檚 two most populous countries plan to remake their geography so that water flows where it never has before. And other countries are taking a similar course. Within the next few months, the European Union will decide whether to cough up as much as $8 billion to help fulfil Spain鈥檚 $24 billion National Hydrological Plan. Its centrepiece is an 850-kilometre canal that will extract up to three-quarters of the flow from the river Ebro, the biggest river in the wetter north of the country, and send it to the country鈥檚 increasingly arid south. There it will irrigate half a million hectares of fields around Almeira and fill taps and water golf courses at tourist resorts on the coast.
There are other, more speculative plans around too. Late last year Australian cattle ranchers and the media magnate Kerry Packer began a campaign to get their government to 鈥渄rought-proof鈥� the country by diverting northern rivers such as the Clarence, Burdekin, Ord and Daly across the outback towards Adelaide (New Scientist, 26 October 2002, p 12). The price tag will be A$40 billion ($25 billion). In the US, around the same time, President George W. Bush called for talks with the Canadian government about buying the contents of its Arctic rivers to irrigate the desert cities of Los Angeles and Las Vegas. Exactly how the water would be shifted was not made clear. But Canada certainly has plenty of it. During the spring melt, roughly a tenth of all the water in the world鈥檚 rivers is in Canadian rivers that empty into the Pacific Ocean. So far Canada has cold-shouldered the plan.
And Africa is not to be outdone. Last October, countries in the rainforests of central Africa signed an agreement on sharing the waters that feed the Congo, the world鈥檚 second-biggest river. Their declared aim is to dam the Oubangui river, a tributary of the Congo, and transfer the river over the watershed into the river Chari, which ends up more than 1000 kilometres away in Lake Chad in the Sahara desert. Lake Chad is disappearing fast. It has lost 90 per cent of its surface area since the mid-1960s through declining rainfall and increasing use of its water for irrigation.
The world undoubtedly faces a growing crisis over the management of its great rivers. Like the Yellow river, the Indus, Colorado and Nile have all periodically run empty in recent years because humans have abstracted their every last drop. Despite this, there is huge unmet demand. More than a billion people have no access to clean drinking water, and while the World Summit last year promised to halve that figure by 2015, nobody is sure where the water will come from. On today鈥檚 trends, one-third of the planet鈥檚 population will be seriously short of water by 2025.
Politicians in China, India, Pakistan, Egypt and other water-stressed countries want their water engineers to find solutions 鈥� and fast. Big seems not just beautiful but essential. But environmental groups warn that emptying some rivers to fill others will lead to ecological havoc.
Indian researchers warn that the canals of the river-linking project, and the reservoirs needed to fill them, will displace up to 2 million people from their homes and carry huge volumes of pollution from the industrial rivers of the north. This, they say, will kill wildlife and pollute drinking water in the south. Many point to the appalling ecological havoc caused a generation ago in central Asia when Russian engineers diverted most of the flows of two giant rivers away from the Aral Sea. The sea dried up, turning the surrounding area into a salt-encrusted wilderness.
In Australia, scientists have banded together under the name the Wentworth Group to argue that more irrigation will just increase salinity in the country鈥檚 fields. And according to the wildlife campaign group WWF, dams are largely responsible for dramatic declines in the world鈥檚 freshwater fisheries. Transfers will further destabilise ecosystems by shifting predator species from one river system to another, it says.
Engineers claim that, far from wrecking ecosystems, their schemes will revitalise the receiving rivers. In China, for instance, they insist that bringing Yangtze water north is the only way of reviving the Yellow river. But many water scientists say these plans are hydrological hubris. The numbers don鈥檛 add up. The water emerging from tunnels, pipes and canals will be too costly for the farmers whose needs they are supposed to meet. The transfers will also be wasteful, with half the water leaking away or evaporating.
Researchers attending the World Water Forum in Kyoto in March argued that collecting and using water more efficiently would lessen the need for more dams. While the Nile runs empty, enough water evaporates from the surface of the Aswan dam to supply all Britain鈥檚 needs. And from Spain to northern China, Mexico to Morocco, farmers still irrigate crops by flooding their fields, when the job could be done far more efficiently with drips from a perforated hose. At a conservative estimate, says Mark Resogrant of the International Food Policy Research Institute in Washington DC, two-thirds of the water sent down irrigation canals never reaches the crops it is meant for. Even modest efforts at using water more efficiently could end the world water crisis, he says. In most places, we can fill the taps without emptying the rivers.
鈥淭he Spanish National Hydrological Plan is clearly crazy,鈥� says Pedro Arrojo-Agudo, an environmental economist from the University of Saragossa. 鈥淭he water will cost more than a dollar for every cubic metre that is delivered 鈥� twice the current cost of the desalination of seawater.鈥� And at that price, few farmers will want it, says Asit Biswas, an international hydrology consultant. Though Biswas has backed many large water engineering schemes, he opposes this one. As European farming subsidies are removed, it will become an expensive white elephant, 鈥渁 magnificent monument to bad planning for decades and even centuries to come,鈥� he says.
Not only that, it will wreck the Ebro delta. This 20-kilometre tongue of sandbanks, lagoons and reed beds protruding into the Mediterranean is one of southern Europe鈥檚 most important wetland nature reserves, as well as Spain鈥檚 largest rice-growing area and an important fish nursery. Starved of water and silt from the river that made it, it will gradually be engulfed by salt and the sea itself, says Ed Maltby, a wetlands specialist at Royal Holloway, University of London. Angry villagers from valleys in the Pyrenees that will be flooded for new dams have joined irate farmers from the Ebro delta in the first demonstrations to demand that Brussels spends less on their homeland, not more.
In fact, Arrojo-Agudo says he would like Spain to get the money. But he wants to see it spent on plugging leaks in city water mains, cutting evaporation losses on Spanish farms, and reusing waste water to irrigate crops and golf courses. Such investment would save many times as much water as could ever be supplied by emptying the Ebro, he says.
Unable to wait for Yangtze water, many provinces in northern China are taking a similar view. In Gansu province, millions of farmers have taken to capturing rain before it ever reaches the rivers, by laying plastic sheets over spare fields and collecting water from their roofs. The combined capacity of this stored water is similar to that of the Three Gorges dam, says Steve Halls, executive director of the UN Environment Programme鈥檚 International Environmental Technology Centre in Japan. And in Shandong province, where the Yellow river meets the sea, the authorities responded to water riots three years ago by agreeing to spend $6 billion by 2006 on water conservation.
Some say China would do better growing more crops in the south rather than pumping the water north. After all, the ancient Grand Canal was dug to transport rice to the north from southern paddies. Everywhere there are alternatives to the water megaprojects. In southern California, half the region鈥檚 water needs could be met by rainfall, yet most of its rain is channelled straight off the tarmac into the ocean. 鈥淲e should be catching our own rain before trying to buy other people鈥檚,鈥� says Andy Lipkis, who runs the TreePeople project, based in Beverly Hills, which is trying to do just that.
India has dozens of half-completed water projects, not to mention a vast, centuries-old infrastructure of forgotten local water-supply systems. In Karnataka, one of the states that the river-transfer project is supposed to benefit, there are tens of thousands of small reservoirs dug to catch the monsoon rains that now lie silted up and abandoned. These should be developed first, says Ramaswamy Iyer, a former director of India鈥檚 water ministry who has since become a prominent critic of the river-transfer plan.
But with official systems seemingly paralysed, many Indian communities are finding local solutions to their water problems. In Rajasthan, thousands of villages that have revived old reservoirs and rainwater collecting systems are finding they still have water when villages relying on distant dams have run dry (New Scientist, 7 September 2002, p 48). In neighbouring Gujarat, farmers have gone further, pouring captured monsoon rains down their wells to recharge underground water reserves for use in the dry season. This spontaneous growth of 鈥減eople鈥檚 technology鈥� has confounded hydrologists and is now active across almost half the state. Even big cities could increase their water resources by up to a third by capturing and storing the rain, rather than letting it run away through storm drains, Halls says.
鈥淟arge engineering companies and state enterprises love the big contracts, of course,鈥� says Tony Allan, Middle East water expert at the School of Oriental and African Studies in London. 鈥淏ut the public too yearns for simple solutions to complex problems.鈥� This helps to make big, prestige projects popular with governments. While they are being built, politicians can bask in the credit for taking bold action to solve a national problem, says Danish economist Bent Flyvbjerg in his book Megaprojects and Risk.
Ministers get to put their names on them, Halls notes: from the Hoover dam in the US to the Indira Ghandi canal in India, Lake Nasser in Egypt and the Saddam river in Iraq, big hydrology projects commemorate their champions. By the time recriminations start to fly over technical problems, ecological calamities and cost overruns, the politicians responsible are usually out of office.
Allan calls these projects 鈥渘ational fantasies鈥� that 鈥渃annot be gainsaid without an intolerable loss of face鈥�. And none comes much bigger than the new generation of water-transfer schemes. Forget the politics of superdams. In the war to fill the world鈥檚 taps and irrigation ditches, these gigantic hydrological schemes are the new battle ground.
