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The United States has already exhausted 60 percent of its groundwater from the Ogallala Aquifer, a vast yet shallow underground water source beneath the Great Plains. The same situation prevails in India, where about 70 percent of the groundwater reserves in the north and northwest have been exhausted. The story repeats itself in China, where the situation is even worse. It is a manmade problem where rising population needs are resulting in the depletion of groundwater.
Farmers in the northern U.S. states of North and South Dakota, Nebraska, Wyoming and Colorado have pumped so much water from the Ogallala Aquifer that this natural reservoir has shrunk to about 40 percent of its original size. It took between 2 and 6 million years to collect so much water, which covers a wide area of about 450,000 square kilometers. Humans have taken just 40 years to exhaust the bulk of it.
India has created a similar problem. Forty years ago, agricultural states like Punjab, Haryana, Uttar Pradesh and the northern region of Rajasthan encouraged farmers to dig boreholes to get free water for agricultural use. Power for pumping out this water was supplied virtually free, which encouraged farmers to dig more boreholes, also known as tube-wells, locally.
Agriculture multiplied and from a deficit agrarian state, India became a surplus state in just 30 years. But the damage to the environment was great. Elsewhere in India the groundwater situation is acute, but the worst affected areas are the above-named four states.
China’s groundwater situation is equally bad. Its northeastern plains, which cover 60,000 square kilometers, receive little rain. This area is the breadbasket of the country, having achieved that status by pumping out huge quantities of groundwater. Some reports indicate that as much as 70 percent of the agricultural water needs are met by groundwater. This is another big environmental disaster in the making. Alternatively, if groundwater is not used, then agriculture productivity will come to a standstill and people will starve.
Similar disasters threaten many other countries. Mexico City has pumped out so much groundwater that some old buildings are sinking. Australia has depleted its groundwater through overuse in times of drought, but has also adopted a set of principles to conserve water and reduce over pumping. Nevertheless, overexploitation remains a problem.
The other side of the problem is that if groundwater is not used for growing crops, people will starve. So nations are being forced to manage their groundwater usage and crop yields better. This will ultimately force cultural change. For China it means that crops like rice, corn and cotton, which require a lot of water, will have to move away from the parched northeast. For India, it means more emphasis must be placed on storing and using excess surface water from the monsoon season. In addition, better irrigation efficiency is required.
There are no readymade solutions; each country must take a fresh look at the issue and devise its own plans. A plan suitable for one region of the country may not be suitable for the entire country.
India has depleted so much of the groundwater in its four agricultural states that the water table has fallen by as much as 120 to 130 feet. But fortunately, this region receives abundant monsoon rains, so a solution is within reach with present-day engineering and technology.
India receives an average 600 millimeters of rain annually. That translates into 4 trillion cubic meters of water falling from the sky. The northeast receives about 30 percent of this precipitation. Central, south and southwestern India receive about 40 percent while 30 percent falls in the north, central and northwest areas. This happens during the three months from July to September and then again during February and March. A mini-sea rains down on India every year.
That amount of rainfall causes floods and untold misery for the population. Although rivers have been tamed, the unusual flat topography in some areas allows excess floodwaters to travel far in a short period of time.
This huge precipitation is also the source of India’s thriving agriculture. High water usage crops like corn, rice and sugarcane are grown during the rainy season. Wheat is grown during the low precipitation season from October to April. This crop rotation fed the country for the last five millennia, until about 1880 when the British taxation system broke the back of the agricultural economy and India became a deficient state. It took about 50 years after 1947 to restore the agricultural productivity balance and enable the country to feed itself.
Only about 15 percent of the total annual rainwater is used for irrigation. The rest reaches the sea via massive river systems. This water, if stored and used for sustained surface irrigation, will help India solve its future agriculture problems. It will also reduce pressure on groundwater. The capital needed for these schemes will come essentially from the future earnings of agricultural products and reduced expenses on flood control.
The water table in 90 percent of the Indian state of Punjab has shrunk. Today, water is found at 150 feet below ground level while 30 years ago it was at 18 to 24 feet. The key culprit is rice cultivation. Thirty years ago Punjab produced mostly wheat; rice was also grown, but much less.
Then a glaring mistake was made at the policy level; the procurement price of wheat was kept low, causing farmers to look for a crop to give them a better return. The procurement price for rice was much higher, although cultivating it was both labor and water intensive. These two handicaps, however, did not deter farmers. Cheap labor from outside the state and the freedom to dig a tube-well to get groundwater became the norm. The state government compounded the problem by supplying virtually free electricity, which resulted in intensive rice farming in Punjab. As the water requirement for rice cultivation is five to seven times greater, groundwater depletion began in a big way.
On the other hand, Punjab has abundant rainfall and alternatives for collecting and storing water. What it requires is capital to build catchment areas and dig canals. That will eliminate the pressure on groundwater.
Major cities in India like New Delhi, Kolkata, Chennai and Mumbai face acute water shortages. Urbanization has resulted in massive pressure on water supplies. Where surface water supplies cannot meet the demand, groundwater is pumped out, causing water tables in most cities to nosedive.
New Delhi’s current water table has gone down to 75 feet from 20 feet in 1975. Some place it at 100 feet. Other urban centers like Kolkata have fared no better. Although Kolkata is closer to the sea and on the banks of a major river, its water table has dropped to 55-60 feet from 15 feet in about 30 years.
India, being rich in surface water resources, should not have groundwater depletion problems. Unfortunately it has, because almost 85 percent of the surface water goes into the sea. If India were to increase surface water use from the present 15 percent to 25 percent, most of the ground water depletion issues would disappear. However, finance and politics remain a major drawback.
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(Hari Sud is a retired vice president of C-I-L Inc., a former investment strategies analyst and international relations manager. A graduate of Punjab University and the University of Missouri, he has lived in Canada for the past 34 years. ©Copyright Hari Sud.)
