Where Has All the Water Gone?

Cherrapunji, India, is one of the wettest places on earth. During the monsoon season, 350 inches [9,000 mm] of rain drench its hills, which lie at the foot of the Himalaya Mountains. Incredible as it may seem, however, Cherrapunji also suffers from water shortage.

SINCE there is little vegetation left to hold the water, it rushes away almost as quickly as it falls from the sky. Two months after the monsoon rains have gone, water becomes scarce. Robin Clarke, in his book Water: The International Crisis, years ago described Cherrapunji as “the wettest desert on earth.” *

Not far downstream from Cherrapunji lies Bangladesh, a densely populated, low-lying country that bears the brunt of the monsoon waters that cascade down the denuded hillsides of India and Nepal. Some years, two thirds of Bangladesh gets flooded. But once the floodwaters subside, the Ganges River slows to a trickle, and the land becomes parched. Over 100 million people in Bangladesh face this cruel, yearly cycle of floods and drought. To make matters worse, well water there has become contaminated with arsenic, which may have already poisoned millions of people.

 In Nukus, Uzbekistan, not far from the Aral Sea, salt rather than arsenic is the problem. White, crusty deposits are enveloping the cotton plants and stunting their growth. The salt rises to the surface from waterlogged subsoil. This problem, called salinization, is not a new one. Mesopotamian agriculture went into decline four thousand years ago for exactly the same reason. Too much irrigation along with poor drainage causes salts in the soil to accumulate at the surface. To get a decent harvest, more and more fresh water must be used. However, eventually the soil becomes useless—for generations to come.

Where Does All the Water Go?

Unfortunately, much of the rain occurs in the form of torrential downpours. These not only cause flooding but also result in water running quickly off the land and into the sea. And some places get a lot of rain, while others get little. Cherrapunji has been known to record more than 1,000 inches [26,000 mm] of rain in one 12-month period, whereas the Atacama Desert in northern Chile may experience several years without any significant rainfall at all.

Furthermore, most of the people on our planet live where water is not plentiful. Relatively few people, for example, live in the tropical areas of Africa and South America where rainfall is abundant. The mighty Amazon River disgorges into the Atlantic Ocean 15 percent of the annual global runoff, yet because the population in that area is sparse, very little water is needed for human consumption. On the other hand, some 60 million people live in Egypt, where rainfall is minimal, and practically all their water needs must be met by the depleted Nile River.

Years ago such disparities in water supplies did not cause serious problems. According to one survey, in 1950 no region on earth suffered from a very low or extremely low water supply. But those times of plentiful water have changed. In arid regions of North Africa and Central Asia, the amount of water available per person has dropped to a tenth of what it was in 1950.

Apart from the population increase and the low rainfall in many densely populated areas, demand for water has risen for other reasons. In the world today, progress and  prosperity go hand in hand with a reliable water supply.

The Rising Demand for Water

If you live in an industrialized country, you have no doubt noticed that factories cluster around important rivers. The reason is simple. Industry needs water to produce practically everything, from computers to paper clips. Food processing also uses a surprising amount of water. Power stations have an insatiable appetite for water and are located alongside lakes or rivers.

The need for water in agriculture is even greater. In many places rainfall is either too little or too unreliable to guarantee a good harvest, so irrigation seemed to be the ideal solution for feeding a hungry planet. As a result of dependence on irrigated crops, agriculture takes a major part of the planet’s supply of fresh water.

In addition, domestic water consumption has grown. During the 1990’s, a staggering 900 million new city dwellers needed decent sanitation and access to safe water. The traditional sources of water, such as rivers and wells, are no longer sufficient for large cities. Mexico City, for example, now has to pipe in water from more than 70 miles [125 km] away and pump it over a range of mountains that rise 4,000 feet [1,200 meters] above the city’s elevation. The situation, says Dieter Kraemer in his report Water: The Life-Giving Source, is “kind of like an octopus; arms going out of the city to try to get water.”

Thus, industry, agriculture, and urban areas have all been clamoring for more water. And many of their demands have been met, for the time being, by drawing on the planet’s reserves—groundwater. Aquifers are one of the earth’s main deposits of fresh water. But they are not inexhaustible. Such water deposits are like money in the bank. You can’t keep on withdrawing it if you make few deposits. Sooner or later, the day of reckoning will come.

Use and Misuse of Groundwater

Groundwater is the water supply we tap into when we sink a well. The United Nations Children’s Fund report Groundwater: The Invisible and Endangered Resource calculates that half the water used for domestic purposes and for irrigating crops comes from this source. Since groundwater is usually less polluted than surface water, it  also provides much of our drinking water, both in cities and in the countryside. If withdrawals were moderate, groundwater supplies would remain constant, since they are regularly renewed by rain that slowly seeps through to these underground reservoirs. But for decades mankind has been siphoning off much more water than the natural water cycle can replace.

The result is that the level of the groundwater gets farther from the surface, and it becomes either uneconomical or impractical to dig deep enough to reach it. When the well runs dry, economic and human disaster results. In India such tragedies have already begun to occur. Since the food for a billion people who live in the central plains of China and India depends on water stored underground, the outlook is alarming.

Depletion of groundwater supplies is further aggravated by contamination. Agricultural fertilizers, human and animal wastes, and industrial chemicals are all finding their way into the groundwater. “Once an aquifer is contaminated, remedial measures can be long and costly, even impossible,” explains a report published by the World Meteorological Organization. “The slow penetration of pollutants has been called a ‘chemical time bomb.’ It threatens humankind.”

The final irony is that water pumped out of the underground aquifers may end up ruining the very land it was intended to irrigate. Much of the irrigated land in the arid or semiarid countries of the world now suffers from salinization. In India and the United States—two of the world’s major food-producing countries—25 percent of irrigated land has already been seriously damaged.

Waste Not, Want Not

Despite all these difficulties, the situation would not be so bleak if the planet’s precious water were used more carefully. Inefficient irrigation methods often squander 60 percent of the water before it reaches the crops. Increased efficiency—using available technology—could reduce industrial water consumption by half. And even urban water use could be cut by 30 percent if broken pipes were fixed quickly.

Measures to conserve water require both the will and the way. Are there sound reasons to believe that our planet’s precious water will be conserved for future generations? Our final article will address this question.

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WATER MAKES THE WORLD GO ROUND

Practically all industrial processes consume large quantities of water.

▪ The production of one ton of steel can consume 280 tons of water.

▪ Manufacturing one pound [1 kg] of paper can require as much as 700 pounds [700 kg] of water (if the factory does not recycle the water).

▪ To make a typical U.S. car, the manufacturer uses 50 times the car’s weight in water.

Agriculture may be just as demanding, especially if livestock is raised in semiarid regions of the earth.

▪ To produce one pound [1 kg] of steak from California beef cattle requires 2,500 gallons [20,500 L] of water.

▪ Processing just one frozen chicken takes at least seven gallons [26 L] of water.

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WHERE IS THE WATER USED?

Agricultural 65%

Industrial 25%

Domestic 10%

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Millions of gallons of water are wasted because of broken water mains and faucets that are left running

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AP Photo/Richard Drew