The PMs Great Man-River project of Libya
What is this project? According to Sandra Postel, in her book Pillar of sand, it is a US$25 billion, 4,000km concrete-pipe river, used for pumping water from a fossil aquifer in the south to the north for irrigation and other uses. The problem is, a fossil aquifer does not replenish its used water. Thus, according to some engineers, it will run dry in 40-60 years.
The PM might also praise a similar water project in Saudi Arabia. It is using its fossil aquifer for crop irrigation at very heavy evaporation in the arid and dry climate. Eighty-five percent of its needs is supplied from this unsustainable source. At present depletion it is expected to run dry in 40 years. And in that time too, salinisation could leave the land dead.
What happens then when the land runs dry? By then population would have increased in the presence of water and food abundance, as indicated by history of traditional societies. They would be in an even more dire situation than they started with.
Take a look at some unsustainable consumption of water from various parts of the world and the consequences.
Models of failure
On Feb 7, 1997, while the Chinese were celebrating the Spring Festival, the Yellow River, the mother river that is the lifeline of North China, went dry. For 130 straight days, no water from Chinas second largest river reached the sea. It flowed again but went dry again for a total of nine times, for a total of 230 days, i.e., nearly two-thirds of the year. At times, some 600km from the sea to Henan province, the river went bone dry.
Though this was not the first time it went dry, it was of the longest duration. The pattern has been set. The Yellow River has been so overexploited, so overdammed and diverted for irrigation, industry, and human consumption that its water cannot sustain the once mighty river anymore. Among the dams on the river are the Sanmenxia and the Yangouxia. To overcome the problem, two of the largest and most technically complex water schemes ever undertaken were proposed: yet another dam, the massive Xiaolangdi, and diversions from the Yangtze to the Yellow River.
Apart from river water, North China uses groundwater. As in the case of river water, groundwater use too is unsustainable. Around Beijing overpumping has caused the water tables to drop 1-2m per year.
In northeast Africa, the Nile has been so dammed and water diverted for irrigation and other purposes, by Ethiopia, Sudan, and mostly by Egypt, that very little water reaches the Mediterranean. Before the construction of the Aswan High Dam, 32bcm a year reached the sea, about 38 percent of the rivers total annual flow. After the dam was built, flow dropped to 6bcm. It dropped further to 3bcm in the mid-1980s, and today only 1.8bcm reaches the sea, and virtually all of that during the few winter months when crops do not need so much irrigation.
Water from the Indus and the Ganges too have been overdrawn that they virtually have no outflow to the sea during the dry months. The diversions of the Ganges by India leave virtually no water for Bangladesh during the dry season. To boost irrigated area, the controversial Narmada Valley Development Programme is being implemented. The centrepiece is the Sardar Sarovar Dam, highly opposed by the Save Narmada Movement.
On the use of ground water, the National Environmental Engineering Institute (Neeri), India, found that overexploitation of ground water resources is widespread across the country and that water tables in critical agricultural areas are sinking at an alarming rate. Overpumping in the coastal areas has also caused sea water to invade freshwater aquifers causing problems for sources of drinking water. According to Neeri, in nine states water demand exceeds supply. This overexploitation of groundwater is the result of the rapid proliferation of wells, now numbering at least six million. Key agricultural areas in India are experiencing worsening water imbalance.
In Bangladesh, during the dry season, heavy pumping causes many wells to go dry. The Chao Phraya river, Thailand, too is experiencing overdemand on its water that the flow is not adequate for navigation. Shortage of its water has made Bangkok resort to overpumping underground water.
Ecological disasters
In the US, since the 1960s, the mighty Colorado too does not reach the sea anymore, except during rare floods. Usually it ends somewhere south of the US border in stagnant pools of pesticide- and salt-laced agricultural run-off. In California, irrigation uses more than 80 percent of supplied water. The dry thirsty state, lacking its own sources of water, imports it, mostly from the Colorado river over great distances. One such line of import is the 770km long California Aqueduct. Its cities too are making more water demands.
Many dry cities of the southwest, Phoenix, Las Vegas, and Reno, among others, tend to forget their water scarcity. They turn on the tap and the water is there. They green their lawns, swim in their pools with gay abandon, using water transported from distant rivers.
To supplement dammed water, groundwater is heavily used. The massive Ogallala aquifer, spanning eight states, is being depleted at the rate of 12bcm a year. Net depletion so far is 325bcm, a volume of the annual flow of 18 Colorado rivers. It used to irrigate 30 percent of US irrigated land but now, because of the overexploitation, only a fifth. As of 1990, 24 percent of the Texas portion has been depleted and subsequently irrigated area of northwest Texas has fallen. In total, more than four million hectares, roughly a fifth of the nations irrigated area, are watered in deficit.
In Central Asia, the Amu Darya and the Syr Darya are so highly diverted, mostly for cotton crop irrigation, that very little water reaches its destination, the Aral Sea. What used to be the biggest freshwater lake in the world, its surface is now less than half the original area and its volume has lost more than two thirds of the original. Due to lack of water, the surrounding areas became polluted by salt and toxic chemicals left behind from agricultural run-offs, causing all kinds of diseases. It is one of the worst man-made ecological disaster.
Consequences
The deficit in irrigation water means crops are being produced unsustainably. Especially for the case of groundwater, the deficit means that at some point, the water will run out and crops cannot be grown anymore. This deficit translates to the fact that some 180 million tons of grain, 10 percent of global production, are produced by depleting water supplies. This is the potential amount of grain that would be lost to feed the increasing population, which will add another two billion people by 2030. The two most populous countries, India and China, have the worst deficits, 104bcm and 30bcm per year respectively. In the third place is the US with 13.6bcm per year.
As Postel calls it, this is a Faustian bargain. A deception, a lull and a sense of plenty and security now traded for the ugliness and sorrow to come. With overexploitation of rivers, we can immediately see with our eyes, here and now, the impacts, but with groundwater aquifer deficit, water is there irrigating fields as usual. What happens 20-30 years from now is somebody elses problem. Or even if it is within our lifetime, we just shrug our shoulders, refusing to see, or just hoping that technology will by then solve the problem.
And do not think sea water desalination is the answer. It just brings another set of problems.
When water is extracted unsustainably, i.e., recharge is less than withdrawal, there is a potential for land subsidence. This is happening in many parts of the world: Mexico City (0.3m per year in some barrios), Beijing (0.1m per year), Houston, Texas (2m in the last four decades), and Bangkok. Subsidence in cities can cause billion-dollar damages, with collapsing building, bridges, roads and highways, water mains, and electrical and communication cables. Mexico City is facing such a cost. A famous statue in Mexico City now stands 9m above the surrounding areas that had subsided since its construction.
The answer then, is to live within our means, through sustainable development and sustainable consumption of resources. Using groundwater for the Klang Valley, as some suggest, is not an answer either, as the above examples show.
Dr ROSLI OMAR is an academic interested in the impact of science and technology on society and environment (being bred on the white heat of technology creed himself), be they dams, genetic engineering, or machines. He believes that science and technology, as used at present, is sustaining an unsustainable development the worst of all possible paradoxes.
