Did you know: For the first time in 2008 the world’s city dwellers outnumbered those in the countryside. The share of urbanites is projected to continue increasing, so that by 2030 some 60 percent of the world’s population will live in cities. For more information view the text and data in Chapter 6 of Plan B 4.0: Mobilizing to Save Civilization.
Chapter 4. Emerging Water Shortages: Water Tables Falling
Scores of countries are overpumping aquifers as they struggle to satisfy their growing water needs. Most aquifers are replenishable, but not all are. When most of the aquifers in India and the shallow aquifer under the North China Plain are depleted, the maximum rate of pumping will be automatically reduced to the rate of recharge.
Fossil aquifers, however, are not replenishable. For these—the vast U.S. Ogallala aquifer, the deep aquifer under the North China Plain, or the Saudi aquifer, for example—depletion brings pumping to an end. Farmers who lose their irrigation water have the option of returning to lower-yield dryland farming if rainfall permits. But in more arid regions, such as in the southwestern United States or the Middle East, the loss of irrigation water means the end of agriculture.
Falling water tables are already adversely affecting harvests in some countries, including China, which rivals the United States as the world’s largest grain producer. A groundwater survey released in Beijing in August 2001 revealed that the water table under the North China Plain, an area that produces over half of the country’s wheat and a third of its corn, is falling fast. Overpumping has largely depleted the shallow aquifer, forcing well drillers to turn to the region’s deep aquifer, which is not replenishable. 5
The survey reported that under Hebei Province in the heart of the North China Plain, the average level of the deep aquifer was dropping nearly 3 meters (10 feet) per year. Around some cities in the province, it was falling twice as fast. He Qingcheng, head of the groundwater monitoring team, notes that as the deep aquifer is depleted, the region is losing its last water reserve—its only safety cushion. 6
His concerns are mirrored in a World Bank report: “Anecdotal evidence suggests that deep wells [drilled] around Beijing now have to reach 1,000 meters [more than half a mile] to tap fresh water, adding dramatically to the cost of supply.” In unusually strong language for a Bank report, it foresees “catastrophic consequences for future generations” unless water use and supply can quickly be brought back into balance. 7
The U.S. Embassy in Beijing reports that wheat farmers in some areas are now pumping from a depth of 300 meters, or nearly 1,000 feet. Pumping water from this far down raises pumping costs so high that farmers are often forced to abandon irrigation. 8
Falling water tables, the conversion of cropland to nonfarm uses, and the loss of farm labor in provinces that are rapidly industrializing are combining to shrink China’s grain harvest. The wheat crop, grown mostly in semiarid northern China, is particularly vulnerable to water shortages. After peaking at 123 million tons in 1997, the harvest has fallen, coming in at 105 million tons in 2007, a drop of 15 percent. 9
The World Bank study indicates that China is mining underground water in three adjacent river basins in the north—those of the Hai, which flows through Beijing and Tianjin; the Yellow; and the Huai, the next river south of the Yellow. Since it takes 1,000 tons of water to produce one ton of grain, the shortfall in the Hai basin of nearly 40 billion tons of water per year (1 ton equals 1 cubic meter) means that when the aquifer is depleted, the grain harvest will drop by 40 million tons—enough to feed 120 million Chinese. 10
As serious as water shortages are in China, they are even more serious in India, where the margin between food consumption and survival is so precarious. To date, India’s 100 million farmers have drilled 21 million wells, investing some $12 billion in wells and pumps. In a survey of India’s water situation, Fred Pearce reported in the New Scientist that “half of India’s traditional hand-dug wells and millions of shallower tube wells have already dried up, bringing a spate of suicides among those who rely on them. Electricity blackouts are reaching epidemic proportions in states where half of the electricity is used to pump water from depths of up to a kilometer.” 11
In Tamil Nadu, a state with more than 62 million peoplein southern India, wells are going dry almost everywhere. According to Kuppannan Palanisami of Tamil Nadu Agricultural University, falling water tables have dried up 95 percent of the wells owned by small farmers, reducing the irrigated area in the state by half over the last decade. As a result, many farmers have returned to dryland farming. 12
As water tables fall, well drillers are using modified oil-drilling technology to reach water, going as deep as 1,000 meters in some locations. In communities where underground water sources have dried up entirely, all agriculture is rain-fed and drinking water must be trucked in. Tushaar Shah, who heads the International Water Management Institute’s groundwater station in Gujarat, says of India’s water situation, “When the balloon bursts, untold anarchy will be the lot of rural India.” 13
India ’s grain harvest, squeezed both by water scarcity and the loss of cropland to non-farm uses, has plateaued since 2000. This helps explain why India reemerged as a leading wheat importer in 2006. A 2005 World Bank study reports that 15 percent of India’s food supply is produced by mining groundwater. Stated otherwise, 175 million Indians are fed with grain produced with water from irrigation wells that will soon go dry. 14
As water tables fall, the energy required for pumping rises. In both India and China, the rising electricity demand from irrigation is satisfied largely by building coal-fired power plants. 15
In the United States, the U.S. Department of Agriculture (USDA) reports that in parts of Texas, Oklahoma, and Kansas—three leading grain-producing states—the underground water table has dropped by more than 30 meters (100 feet). As a result, wells have gone dry on thousands of farms in the southern Great Plains, forcing farmers to return to lower-yielding dryland farming. Although this mining of underground water is taking a toll on U.S. grain production, irrigated land accounts for only one fifth of the U.S. grain harvest, compared with close to three fifths of the harvest in India and four fifths in China. 16
For the seven states that draw on Colorado River water—Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming—the USDA survey shows an irrigated area decline in each from 1997 to 2002. In the two leading irrigation states, California and Colorado, the area dropped by 2 percent and 24 percent respectively. The 2007 survey will likely show further shrinkage in irrigated area. 17
Pakistan , a country with 164 million people that is growing by 3 million per year, is also mining its underground water. In the Pakistani part of the fertile Punjab plain, the drop in water tables appears to be similar to that in India. Observation wells near the twin cities of Islamabad and Rawalpindi show a fall in the water table between 1982 and 2000 that ranges from 1 to nearly 2 meters a year. 18
In the province of Balochistan, which borders Afghanistan, water tables around the capital, Quetta, are falling by 3.5 meters per year. Richard Garstang, a water expert with the World Wildlife Fund and a participant in a study of Pakistan’s water situation, said in 2001 that “within 15 years Quetta will run out of water if the current consumption rate continues.” 19
The water shortage in Balochistan is province-wide. Sardar Riaz A. Khan, former director of Pakistan’s Arid Zone Research Institute in Quetta, reports that six basins have exhausted their groundwater supplies, leaving their irrigated lands barren. Khan expects that within 10–15 years virtually all the basins outside the canal-irrigated areas will have depleted their groundwater supplies, depriving the province of much of its grain harvest. 20
Future irrigation water cutbacks as a result of aquifer depletion will undoubtedly reduce Pakistan’s grain harvest. Countrywide, the harvest of wheat—the principal food staple—is continuing to grow, but more slowly than in the past. 21
Iran , a country of 71 million people, is overpumping its aquifers by an average of 5 billion tons of water per year, the water equivalent of one third of its annual grain harvest. Under the small but agriculturally rich Chenaran Plain in northeastern Iran, the water table was falling by 2.8 meters a year in the late 1990s. New wells being drilled both for irrigation and to supply the nearby city of Mashad are responsible. Villages in eastern Iran are being abandoned as wells go dry, generating a flow of “water refugees.” 22
Saudi Arabia , a country of 25 million people, is as water-poor as it is oil-rich. Relying heavily on subsidies, it developed an extensive irrigated agriculture based largely on its deep fossil aquifer. After several years of supporting wheat prices at five times the world market level, the government was forced to face fiscal reality and cut the subsidies. Its wheat harvest dropped from a high of 4.1 million tons in 1992 to 2.7 million tons in 2007, a drop of 34 percent. 23
Craig Smith writes in the New York Times, “From the air, the circular wheat fields of this arid land’s breadbasket look like forest green poker chips strewn across the brown desert. But they are outnumbered by the ghostly silhouettes of fields left to fade back into the sand, places where the kingdom’s gamble on agriculture has sucked precious aquifers dry.” Some Saudi farmers are now pumping water from wells that are 4,000 feet deep, nearly four fifths of a mile or 1.2 kilometers. 24
A 1984 Saudi national survey reported fossil water reserves at 462 billion tons. Half of that, Smith reports, has probably disappeared by now. This suggests that irrigated agriculture could last for another decade or so and then will largely vanish. 25
In neighboring Yemen, a nation of 22 million, the water table under most of the country is falling by roughly 2 meters a year as water use outstrips the sustainable yield of aquifers. In western Yemen’s Sana’a Basin, the estimated annual water extraction of 224 million tons exceeds the annual recharge of 42 million tons by a factor of five, dropping the water table 6 meters per year. World Bank projections indicate the Sana’a Basin—site of the national capital, Sana’a, and home to 2 million people—may be pumped dry by 2010. 26
In the search for water, the Yemeni government has drilled test wells in the basin that are more than a mile deep—depths normally associated with the oil industry—but they have failed to find water. Yemen must soon decide whether to bring water to Sana’a, possibly by pipeline from coastal desalting plants, if it can afford it, or to relocate the capital. Either alternative will be costly and potentially traumatic. 27
With its population growing at 3 percent a year and with water tables falling everywhere, Yemen is fast becoming a hydrological basket case. With its grain production falling by two thirds over the last 20 years, Yemen now imports four fifths of its grain supply. Living on borrowed water and borrowed time, Yemen ranks twenty-fourth on Foreign Policy’s list of failing states. 28
Israel , even though it is a pioneer in raising irrigation water productivity, is depleting both of its principal aquifers—the coastal aquifer and the mountain aquifer that it shares with Palestinians. Because of severe water shortages, Israel has banned the irrigation of wheat. Conflicts between Israelis and Palestinians over the allocation of water are ongoing. 29
In Mexico—home to a population of 107 million that is projected to reach 132 million by 2050—the demand for water is outstripping supply. Mexico City’s water problems are well known. Rural areas are also suffering. In the agricultural state of Guanajuato, the water table is falling by 2 meters or more a year. In the northwestern state of Sonora, farmers once pumped water from the Hermosillo aquifer at a depth of 35 feet. Today they pump from more than 400 feet. At the national level, 51 percent of all the water extracted from underground is from aquifers that are being overpumped. 30
Since the overpumping of aquifers is occurring in many countries more or less simultaneously, the depletion of aquifers and the resulting harvest cutbacks could come at roughly the same time. And the accelerating depletion of aquifers means this day may come soon, creating potentially unmanageable food scarcity.
5. Michael Ma, “Northern Cities Sinking as Water Table Falls,” South China Morning Post, 11 August 2001; share of China’s grain harvest from the North China Plain based on Hong Yang and Alexander Zehnder, “China’s Regional Water Scarcity and Implications for Grain Supply and Trade,” Environment and Planning A, vol. 33 (2001), and on USDA, op. cit. note 2.
6. Ma, op. cit. note 5.
7. World Bank, China: Agenda for Water Sector Strategy for North China (Washington, DC: April 2001), pp. vii, xi.
8. John Wade, Adam Branson, and Xiang Qing, China Grain and Feed Annual Report 2002 (Beijing: USDA, 21 February 2002).
9. Wheat production from USDA, op. cit. note 2.
10. World Bank, op. cit. note 7, p. viii; calculations based on 1,000 tons of water to produce 1 ton of grain in FAO, Yield Response to Water (Rome: 1979).
11. Number of farmers and well investment from Peter H. Gleick et al., The World’s Water 2006–2007 (Washington, DC: Island Press, 2006), p. 148; number of wells and rate of aquifer depletion from Fred Pearce, “Asian Farmers Sucking the Continent Dry,” New Scientist.com, 28 August 2004.
12. Pearce, op. cit. note 11; Tamil Nadu population from 2001 census, “Tamil Nadu at a Glance: Area and Population,” at www.tn.gov.in.
13. Pearce, op. cit. note 11.
14. Grain production and imports from USDA, op. cit. note 2; John Briscoe, India’s Water Economy: Bracing for a Turbulent Future (New Delhi: World Bank, 2005); population data from U.N. Population Division, op. cit. note 1.
15. Energy used for groundwater pumping from Tingju Zhu et al., “Energy Price and Groundwater Extraction for Agriculture: Exploring the Energy-Water-Food Nexus at the Global and Basin Level,” presented at Linkages Between Energy and Water Management for Agriculture in Developing Countries, Hyderabad, India, January 2007; coal from U.S. Department of Energy, Energy Information Administration, Country Analysis Briefs: India and Country Analysis Briefs: China (Washington, DC: updated January 2007 and August 2006).
16. USDA, Agricultural Resources and Environmental Indicators 2000 (Washington, DC: February 2000), Chapter 2.1, p. 6; irrigated share calculated from FAO, ResourceSTAT, electronic database, at faostat.fao.org/site/405/default.aspx, updated 30 June 2007; harvest from USDA, op. cit. note 2; Sandra Postel, Pillar of Sand (New York: W. W. Norton & Company, 1999), p. 77.
17. USDA, “Table 10: Irrigation 2002 and 1997,” 2002 Census of Agriculture, vol. 1 (Washington, DC: June 2004), pp. 319–26.
18. U.N. Population Division, op. cit. note 1; fall in water table from “ Pakistan: Focus on Water Crisis,” U.N. Integrated Regional Information Networks News, 17 May 2002.
19. “ Pakistan: Focus on Water Crisis,” op. cit. note 18; Garstang quoted in “Water Crisis Threatens Pakistan: Experts,” Agence France-Presse, 26 January 2001.
20. Sardar Riaz A. Khan, “Declining Land Resource Base,” Dawn (Pakistan), 27 September 2004.
21. USDA, op. cit. note 2.
22. U.N. Population Division, op. cit. note 1; overpumping from Chenaran Agricultural Center, Ministry of Agriculture, according to Hamid Taravati, publisher, Iran, e-mail to author, 25 June 2002.
23. U.N. Population Division, op. cit. note 1; Craig S. Smith, “Saudis Worry as They Waste Their Scarce Water,” New York Times, 26 January 2003; grain production from USDA, op. cit. note 2.
24. Smith, op. cit. note 23.
26. U.N. Population Division, op. cit. note 1; Yemen’s water situation from Christopher Ward, “Yemen’s Water Crisis,” based on a lecture to the British Yemeni Society in September 2000, July 2001; Christopher Ward, The Political Economy of Irrigation Water Pricing in Yemen (Sana’a, Yemen: World Bank, November 1998).
27. Marcus Moench, “Groundwater: Potential and Constraints,” in Ruth S. Meinzen-Dick and Mark W. Rosegrant, eds., Overcoming Water Scarcity and Quality Constraints (Washington, DC: International Food Policy Research Institute, October 2001).
28. U.N. Population Division, op. cit. note 1; Yemen’s water situation from Ward, Political Economy of Irrigation Water Pricing, op. cit. note 26; grain production and imports from USDA, op. cit. note 2, updated 13 September 2005; Fund for Peace and Carnegie Endowment for International Peace, “The Failed States Index 2007,” Foreign Policy, July/August 2007, p. 57.
29. Deborah Camiel, “ Israel, Palestinian Water Resources Down the Drain,” Reuters, 12 July 2000.
30. U.N. Population Division, op. cit. note 1; Tushaar Shah et al., The Global Groundwater Situation: Overview of Opportunities and Challenges (Colombo, Sri Lanka: International Water Management Institute, 2000); Karin Kemper, “Groundwater Management in Mexico: Legal and Institutional Issues,” in Salman M. A. Salman, ed., Groundwater: Legal and Policy Perspectives, Proceedings of a World Bank Seminar (Washington, DC: World Bank, 1999), p. 117; U.N. Development Programme (UNDP), Human Development Report 2006 (Gordonsville, VA: Palgrave Macmillan, 2006), p. 146.
Copyright © 2008 Earth Policy Institute