WATER DEFICITS GROWING IN
Water Shortages May Cause Food Shortages
The world is incurring a
vast water deficit. It is largely invisible, historically
recent, and growing fast. Because this impending crisis
typically takes the form of aquifer overpumping and falling
water tables, it is not visible. Unlike burning forests
or invading sand dunes, falling water tables cannot be
readily photographed. They are often discovered only when
wells go dry.
The world water deficit is recent--a product of the tripling
of water demand over the last half-century and the rapid
worldwide spread of powerful diesel and electrically driven
pumps. The drilling of millions of wells has pushed water
withdrawals beyond the recharge of many aquifers. The
failure of governments to limit pumping to the sustainable
yield of aquifers means that water tables are now falling
in scores of countries.
We are consuming water that belongs to future generations.
In some countries, the fall of water tables is dramatic.
In Yemen, a country of 19 million, the water table under
most of the country is falling by roughly 2 meters a year
as water use far exceeds the sustainable yield of aquifers.
World Bank official Christopher Ward observes that "groundwater
is being mined at such a rate that parts of the rural
economy could disappear within a generation."
In the basin where the capital, Sana'a, is located and
where the water table is falling 6 meters (nearly 20 feet)
per year, the aquifer will be depleted by the end of this
decade. In the search for water, the Yemeni government
has drilled test wells in the basin that are 2 kilometers
(1.2 miles) 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
from coastal desalting plants, or to relocate the capital.
Iran, a country of 70 million people, is facing an acute
shortage of water. Under the agriculturally rich Chenaran
Plain in northeastern Iran, the water table was falling
by 2.8 meters a year in the late 1990s. But in 2001 the
cumulative effect of a three-year drought and the new
wells being drilled both for irrigation and to supply
the nearby city of Mashad dropped the aquifer by an extraordinary
8 meters. Villages in eastern Iran are being abandoned
as wells go dry, generating a swelling flow of water refugees.
Shortages of water in Egypt,
which is entirely dependent on the Nile River, are well
known. With the Nile now reduced to a trickle as it enters
the Mediterranean, the three principal countries of the
Nile River Basin--Egypt, Ethiopia, and Sudan--can each
increase its take from the river only at the expense of
the other two. With the combined population of these countries
projected to climb from 167 million today to 264 million
in 2025, all three are facing growing grain deficits as
a result of water shortages.
In Mexico--home to 104 million people and growing by 2
million per year--the demand for water has outstripped
supply in many states. In the agricultural state of Guanajuato,
for example, the water table is falling by 1.8-3.3 meters
a year. Mexico City's water problems are legendary. How
the United States and Mexico share the water of the Rio
Grande has become a thorny issue in U.S.-Mexican relations.
A World Bank study of the water balance in the North China
Plain calculated an annual deficit of 37 billion tons
of water. Using the rule of thumb of 1,000 tons of water
to produce 1 ton of grain, this is equal to 37 million
tons of grain--enough to feed 111 million Chinese at their
current level of consumption. In effect, 111 million Chinese
are being fed with grain produced with water that belongs
to their children. Scores of other countries are running
up regional water deficits, including nearly all of those
in Central Asia, the Middle East, and North Africa, plus
India, Pakistan, and the United States.
Historically, water shortages were local, but in an increasingly
integrated world economy, the shortfalls can cross national
boundaries via the international grain trade. Water-scarce
countries often satisfy the growing needs of cities and
industry by diverting water from irrigation and importing
grain to offset the resulting loss of production. Since
a ton of grain equals 1,000 tons of water, importing grain
is the most efficient way to import water. World grain
futures will soon in effect become world water futures.
Although military conflicts over water are always a possibility,
future competition for water seems more likely to take
place in world grain markets. This can be seen with Iran
and Egypt, both of which now import more wheat than Japan,
traditionally the world's leading importer. Imports supply
40 percent or more of the total consumption of grain--wheat,
rice, and feedgrains--in both countries. Numerous other
water-short countries also import much of their grain.
Morocco brings in half of its grain. For Algeria and Saudi
Arabia, the figure is over 70 percent. Yemen imports nearly
80 percent of its grain, and Israel, more than 90 percent.
Seventy percent of world water use, including all the
water diverted from rivers and pumped from underground,
is used for irrigation, 20 percent is used by industry,
and 10 percent goes to residences. Thus if the world is
facing a water shortage, it is also facing a food shortage.
Water deficits, which are already spurring heavy grain
imports in numerous smaller countries, may soon do the
same in larger countries, such as China or India.
Even with the overpumping of its aquifers, China is developing
a grain deficit. After rising to an historical peak of
392 million tons in 1998, grain production in the world's
largest nation fell below 350 million tons in 2000, 2001,
and 2002. The resulting annual deficits of 40 million
tons or so have been filled by drawing down the country's
extensive grain reserves. But if this situation continues,
China soon will be forced to turn to the world grain market.
When this happens, it will almost certainly drive grain
prices upward. Remember that when the Soviets decided
after a poor harvest in 1972 to import grain rather than
tighten their belts, the world wheat price climbed from
$1.90 per bushel in 1972 to $4.89 in 1974.
The two keys to stabilizing aquifers are raising water
prices and stabilizing population. The first step is to
eliminate the pervasive subsidies that create artificially
low prices for water in so many countries. The next is
to raise water prices to the point where they will reduce
pumping to a sustainable level by raising water productivity
and reducing water use in all segments of society. Low-income
urban consumers can be protected with "lifeline rates"
that provide for basic needs at an affordable price. Prices
of underground water can be raised by installing meters
on pumps and charging for water as Mexico has done or
by auctioning permits to operate wells. Either way, water
The second key is to quickly stabilize population in water-short
countries. Most of the 3 billion people projected to be
added worldwide by mid-century will be born in countries
already experiencing water shortages. Unless population
growth can be slowed quickly by investing heavily in female
literacy and family planning services, there may not be
a humane solution to the emerging world water shortage.
Examples of Aquifer Depletion
table falling by 2–3 meters per year under much of
the Plain. As pumping costs rise, farmers are abandoning
is heavily dependent on water from Ogallala aquifer,
largely a fossil aquifer. Irrigated area in Texas,
Oklahoma, and Kansas is shrinking as aquifer is depleted.
table is falling under the Punjab and in the provinces
of Baluchistan and North West Frontier.
Haryana, Rajasthan, Andhra Pradesh, Maharashtra, Tamil
Nadu, and other states
tables falling by 1–3 meters per year in some parts.
In some states extraction is double the recharge.
In the Punjab, India’s breadbasket water table falling
by nearly 1 meter per year.
Plain, northeastern Iran
table was falling by 2.8 meters per year but in 2001
drought and drilling of new wells to supply nearby
city of Mashad dropped it by 8 meters.
table falling by 2 meters per year throughout country
and 6 meters a year in Sana’a basin. Nation’s capital,
Sana’a, could run out of water by end of this decade.
this agricultural state, the water table is falling
by 1.8–3.3 meters per year.
China from Michael Ma, “Northern Cities Sinking as
Water Table Falls,” South China Morning Post, 11 August
2001; United States from Postel, Sandra Postel, Pillar
of Sand (New York: W.W. Norton & Company, 1999), and
from Bonnie Terrell and Phillip N. Johnson, “Economic
Impact of the Depletion of the Ogallala Aquifer: A
Case Study of the Southern High Plains of Texas,”
presented at the American Agricultural Economics Association
annual meeting in Nashville, TN, 8–11 August 1999;
Pakistan, India, and Mexico in Tushaar Shah et al.,
The Global Groundwater Situation: Overview of Opportunities
and Challenges (Colombo, Sri Lanka: International
Water Management Institute, 2000); Postel, op. cit.
this note; Iran from Chenaran Agricultural Center,
Ministry of Agriculture, according to Hamid Taravati,
publisher, Iran, e-mail to author, 25 June 2002; Christoper
Ward, “Yemen’s Water Crisis,” based on a lecture to
the British Yemeni Society in September 2000, July