China is facing an increasingly desperate search to find enough fresh water, both for human consumption and for industry. Whatever water exists is in the wrong place, held in collapsing dams, based in near-drained natural aquifers, is highly polluted or flowing out to countries downstream who will not be happy if China tries to cut the flow of certain strategic rivers. With growing desertification, changing rainfall patterns, algal blooms in lakes and the ever-present threat of earthquake, what can it do?
China’s per capita water resources are not unusual by world standards. However, in this continental-sized country, they suffer from poor distribution. Southern China is reasonably provided with 80% of the water, whereas North China is probably the largest contiguous piece of water-short land in the world. In total 27% of China’s land mass is officially estimated to be desert. However, this figure has not been revised for more than a decade. Between 1950-2000, 24,000 villages in northern and western China disappeared forever beneath the expanding desert sands, which every year get closer to Beijing.
Partly by geography, partly by population and standing, Beijing is the epicentre of this northern challenge. The problems of water shortages are diverse: limited rainfall, lower water resources, reducing water table, increasing subsidence, high pollution and demand above supply.
From 2008-11 parts of the country suffered some of the worst drought conditions in a century. In northern China 7m people were affected. In Guandong in 2009 rainfall was down by 13%. In 2010 Yunnan suffered its worst drought for a century and the main airport at Kunming developed cracks in the runway.
In some research, Beijing’s rainfall has been declining since 1815. It certainly seems to have been falling since the 1960s. Recently the annual average has been 43cms compared with Shanghai at 142cms and New York at 109cms. Since the 1980s few wet years occurred against over 25 years of drought.
In 1949, the per capita water resources were 995 litres and steadily fell to below 100l this year, where international definition of shortage is 1682l. This is due to a combination of excessively depleting the Beijing Plain aquifers, interrupting their natural recharge, complicated by large population increases.
In parts of the Beijing Plain groundwater levels have been falling since at least the 1950s. From the 1970s until 2006, the water table or depth underground of the aquifer groundwater, fell by over 20m. In fact in East Beijing it has fallen by 25m even since 1990. Recent years have seen an “accelerated rapid decrease”. From 1999 until 2009 the Beijing level fell 9.75m, rendering many wells inoperative. Upcountry springs are scarcely productive owing to deforestation. In much of northern China the water table is falling by over a metre each year.
The excessive depletion of aquifers in and around Beijing has caused three “cones of depression” surrounding and under the city. One is estimated to cover over 980 sq.kms. These have led to subsidence in the centre of almost a metre, “causing cracks in buildings, breakage of some pipelines and instability of foundations”. In fact there has been subsidence at the airport and sensors have been placed on the Beijing subway and the high speed railway tracks.
One of Beijing’s two reservoirs, Guanting, has been too polluted to produce drinking water since 1997. One of the two principal rivers, the Yonding, has ceased to be usable for drinking water owing to pollution. Last year Beijing announced a $16bn plan to build almost 1300kms of sewage pipes and upgrade 20 sewage plants to reduce pollution. Seventy per cent of the groundwater in North China is unfit for human consumption. Some estimates say that 300m people in China regularly drink contaminated water. Two-thirds of them end up getting ill.
Even the water that is captured in dams is not safe. In 2009 water minister Chen Lei stated that 43% of China’s dams could collapse if there was heavy rainfall. Ninety percent of these are in Sichuan, where they were heavily shaken by the 2008 earthquake. Unfortunately, for those towns and cities dependent on water, the shortfall can only be bridged by diverting water from neighbouring communities and digging well below the recommended levels in the aquifers.
The solutions of the authorities are in the short term to continue pushing industry and irrigation out of the municipality, requisitioning neighbouring water and digging deeper. There is also some tree planting going on, with the $100bn Great Green Wall of China, spanning over 3200 kms across the north of the country, but poor tree choice, poor husbandry and other factors are undermining the strategy.
Longer term, the goals are to introduce desalination and one of the biggest engineering programmes in history, the South North Water Diversion which will bring Tibetan glacier water from the Yangtze across the whole country to the north-east.
Unfortunately, there are problems with these solutions. While the authorities have had considerable success moving water-intensive industry out of the city and diverting the still significant agriculture sector from irrigation, the giddy urban population rise has eroded all those gains. It is a zero-sum game to appropriate water from a neighbouring province with its own water problems.
Continual digging deeper into the aquifers not only reduces water reserves beyond the ability of nature to recharge – hence imperilling future generations – but also risks exacerbating the already ominous subsidence across the North China plain. Desalination plants are expensive because they use a lot of energy and if they are coal-powered, will also produce huge amounts of smog.
The South North Diversion lacks full funding for completion and safety. Indeed the full cost has not been yet calculated. It also requires substantial forced relocation, uses waterways plagued with pollution, damages the ecology and possibly most dangerously, is angering neighbours from Russia through India to Vietnam who rely on the same Tibetan waters for their rivers.
Beijing’s crisis needs demand not supply-led solutions. Agriculture uses 70% of China’s water and yet 55% of the water sourced by the agricultural sector is lost before it ever reaches the fields. The state plans to reduce this to 53%. Not really very impressive. Any serious approach to this issue would address one third of national water use. Alongside this, and to bring some sense of reality to consumers, water pricing needs approaching with vigour and sophistication.
Officials are understandably nervous. However, more experiments in limited public consultation and adroit use of the media can effectively sell the process. The un-emphasised factor which regularly wrecks official water supply calculations is the spectacular migration from country to city. Beijing must reassess its obsession with increasing urbanisation.