CHAPTER 4 ~ SUSTAINABILITY  OF  OUTPUTS  OF  THE  WORLD'S  IRRIGATED  LANDS  AND  FRESHWATER  RESOURCES ~

Updated August, 2010

Note: The data found below represent a sampling of a much larger collection of data compiled in "Irrigated Lands Degradation: A Global Perspective," found on this same website.

~ TABLE OF CONTENTS ~

A

Elements of Non-Sustainability

B

Basic Facts about the Water-Soil-Salt System

C

Basic Facts About Irrigation Systems

D

Irrigation System Growth

E

Water Supplies and Urbanization Limiting Irrigation ~ [E1]~ Global, [E2]~ Middle East and North Africa, [E3]~ U.S. , [E4]~ South and Southeast Asia, [E5]~Europe and Northern Asia,

F

Salinity and Water-logging Effects Limiting Irrigation ~[F1]~ Global, [F2]~ Asian Sub-Continent, [F3]~ North America, [F4]~ Middle East - North Africa, [F5]~Central Asia, [F6]~ Far East, [F7]~ Australia and Oceania, [F8]~ Latin America,

G

Irrigation System Abandonment

H

Surface Water Problems ~ [H1]~ Asian Sub-Continent, [H2]~ Eastern Asia, [H3]~ Middle East - North Africa, [H4]~ North America, [H5]~Central Asia, [H6]~Africa,

I

Aquifer Degradation ~ [I1]~ Global, [I2]~ Asian Sub-Continent, [I3]~ Eastern Asia, [I4]~ Middle-East-North Africa, [I5]~ Sub-Saharan Africa, [I6]~Southeast Asia, [I7]~ North America, [I8]~ South America, [I9]~ Europe,

J

Global-Scale Water Scarcity

K

Global Water Inventory- and Transfer Basics

~

References (ir9.html)

Go to Table of Contents of this Entire  Document on Sustainability Issues (in the Introductory Chapter)
Go to home page of this website ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")
Go to Chapter 1 of this Sustainability Document ("Sustainability of the Outputs of the World's Soils and Croplands")
Go to Chapter 2 of this Sustainability Document ("Sustainability of the Outputs of the World's Forest Land")
Go to Chapter 3 of this Sustainability Document ("Sustainability of the Outputs of the World's Grazing Lands")
Go to Chapter 5 of this Sustainability Document ("Sustainability of the Outputs of the World's Fisheries")

Section [A] ~ ELEMENTS OF NON-SUSTAINABILITY ~

(Irrigation System Sustainability - Politics and History) "The major problems of irrigation system development and operation are not technical, but relate to the socio-political situation (74F1)." The author of that statement (a hydrologist) is reasonable certain that most, if not all, the water projects he designed will meet the same fate as the ancient Middle-Eastern irrigation projects that people now find buried in the sands, or sparkling with white salt crusts in the sun, totally vegetation-free. What that author is saying is that very few present-day irrigation systems are designed with protection against salt build-up (salinization), i.e. with systems of underground drainage tiles to: (1) carry off the salt that irrigation water accumulates as it percolates down through the soil, and (2) to prevent the water table, with or without its salt load, from rising up to the root zones of the plants being irrigated. Even the World Bank does not require drainage tiles in the irrigation systems it finances (95J1), nor does the world Bank require water conservation measures such as micro- or drip-irrigation to be installed. More than 50% of the world's irrigated soils are affected by secondary salinization, alkalization and waterlogging (Refs. 355, 356, p. 207 of Ref. (88S1)) (FAO and UNESCO data). The threat is greater in developing nations because they lack the financial capital required to: (1) invest in the drainage systems required to prevent salinization and water-logging, or (2) to build new irrigation systems or (3) to afford the water needed to restore degraded or abandoned irrigation systems (water that, in the short run, provides no crops). The world's semi-arid and arid landscapes are dotted with huge white, salt-encrusted patches that were once irrigation systems that have never recovered because restoration costs had become unaffordable.

(Irrigation and Subsidies) Modern societies not only ignore the lessons from the past, they also pay people to follow in the footsteps of their ancestors. Water obtained from surface water and groundwater is sold to irrigators at a price that is typically about 10-20% of the cost, to the taxpayer, of supplying water to irrigators, effectively subsidizing the consumption of water, encouraging waste (e.g. irrigating alfalfa fields in California) and making water conservation technologies like micro-irrigation non-competitive***. This is true virtually the world over. Developing nations pay an especially dear (but politically essential) price for subsidizing irrigation. The governments' income generated from irrigators is hence not sufficient to repay the loans the governments receive from external entities like the World Bank or the International Monetary Fund (IMF) to build the dams, water ducts and irrigation systems. The loss, instead, is added to their staggering external debt (now well over $2.5 trillion for the developing world as a whole). The result is economy-wrecking loan repayment costs and a drying up of financial capital for future investments in irrigation.

Subsidizing the consumption of a scarce and vital resource has serious consequences; yet few countries, if any, have a well-functioning system for allocating water between competing demands and needs (05F2). Non-sustainability is largely the result of a variety of expediencies (such as subsidies) that increase current food supplies while risking, and reducing, future food supplies. The principle expediencies are (1) neglecting to deal effectively with salinization and (2) water-logging, and consuming water supplies beyond their sustainable limits. Other expediencies are described below.

One need only examine the data below and elsewhere*** to see the problems looming for mankind as a result of not taking water supply/ demand/ conservation issues seriously - and they are not being taken seriously. At least this author has never run across any evidence of seriousness in seeking laws, policies and practices that ensure that water is used and consumed sustainably. Human pressures on freshwater resources focused first on surface waters until major rivers started to dry up before they reached the sea. Then they focused on dams of ever-increasing size and number (partly to keep ahead of the large and growing erosion sediment loads that keep filling up the backwaters of dams). This led to irrigation systems of ever increasing scale that fed initially on surface waters. Now the trend is to rely, to ever-increasing extents, on ground water aquifers that, in much of the world, are being drained dry.

(The role of Irrigated Lands in Producing the world's Food) Something on the order of 70% of the water "consumed" (for all intents and purposes) by man is irrigation water (97W1). (82% goes to agriculture as a whole.) That 70% figure for irrigation becomes 81% if one apportions reservoir evaporation losses among the other uses of water (00S4). The world's irrigation systems produce on the order of 40% (by weight) of the world's food supply (00W2). On a dollar basis they produce about 60% of the world's food supply. This is because higher-value crops are more likely to be irrigated (97C1), reflecting the huge financial capital investments that modern irrigation systems require. Productivities (in dollars worth of output per acre of irrigated lands) are about 7 times greater than those of rain-fed croplands, and 36 times greater than those of range lands (Ref. 18 of Ref. (97C1)) that are typically located on semi-arid or arid lands. In fact, the world's 2.7 million km2 of irrigated land produce about 74% more than the world's 40-50 million km2 of rangeland on a dollar-basis (97C1). Irrigation expansion contributed over 50% of the increase in global food production during 1965-85 (96G2). This illustrates the extreme effects of water on productivity and explains why irrigated lands are so crucial in the global food supply system.

(Salinity effects on Irrigation System Sustainability) The sustainability of irrigation systems rests largely on systems of drainage pipes a few feet below the soil surface to protect against salt build-up. (The drainage system also prevents the water table from rising up to the root zone of plants, starving them of oxygen.) The percentage of irrigation systems that contain such drainage systems is estimated to be extremely small. Salinity problems are couples with water supply problems. Increasing human pressures on the land, and diminishing water supplies force irrigators to try to increase production from each drop of water. But doing this increases salinity, resulting in an ever-steeper downward spiral of positive feedbacks. The lack of protection against salt build-up poses serious threats to most irrigated cropland in terms of decline and eventual abandonment - invariably permanent (74F1). (Only irrigation systems in monsoon climates do not require this protection.) Because salinity effects take some decades to become apparent, and because so many irrigation systems are so new, rates of productivity-degradation and abandonment of irrigated lands are certain to grow well beyond current rates in coming decades. As human (population) pressures on the land increase, and as the developing world's external debt spirals out of control, strategies for sustainability (fallowing, drainage tiles, drip irrigation) become increasingly hard to afford and to defend from the interests of short-term expediency. This hastens increased salinization, waterlogging, declining productivity, and abandonment.

(The Overall Water Supply Issue) The other major sustainability issue rests on the sustainability of water supplies for irrigation. Urban consumption of water is growing several times faster that human population growth, and urban users have the political and economic power to reallocate irrigation water to urban uses. In the late 1990s, at least 400 million people lived in regions with severe water shortages. By 2050, this number is expected to be 4 billion (98S1). Thus large-scale reallocations of irrigation water to household-, municipal- and industrial uses are virtually certain in coming decades. The International Food Policy Research Institute's (IFPRI's) "business-as-usual" scenario (02I1) forecasts that, by 2025, freshwater scarcity will cause annual global losses of 350 million metric tonnes of food production. For comparison, global cereal production in 1990 was 1921 million metric tonnes (98D1). Grains are the source of 2/3 of mankind's caloric food intake. Water consumption by agriculture (almost entirely for irrigation) accounts for 82% of human-based water consumption. If reservoir evaporation losses are apportioned among all other consumption categories, agriculture accounts for 93% of water consumption by humans (96P2). Thus irrigation is the primary reason why many of the world's major rivers no longer reach the oceans during at least parts of the year (99P1). It is also the primary reason why the number of lakes and the sizes of inland seas are shrinking so rapidly, and why the number of endangered lakes is now so large as to pose a threat to up to one billion people (01A1).

Water supply issues are best divided into two somewhat independent issues - surface water issues and groundwater issues. These two issues are taken up below.

(Surface Water) More than half the world's 500 largest rivers have been seriously depleted. Some have been reduced to a trickle in what the UN warned is a "disaster in the making" (06L1). Irrigation is the primary reason why these rivers no longer reach the oceans during parts of the year. It is also the primary reason why the number of lakes (and the sizes of inland seas) is shrinking so rapidly, and why the number of endangered lakes now poses a threat to up to one billion people ***.

(Aquifers [Ground Water]) As rivers, lakes, and inland seas, started to dry up due to over-extraction of water*** technological advances came along around 1950 in the form of sophisticated diesel- and electric-powered pumps that enabled the low-cost extraction of huge flows of "ground waters." Irrigation water now comes increasingly from aquifers. Predictably, what happened to surface waters is now happening to ground waters: As a result, groundwater tables are dropping globally, despite the fact that 97% of the earth's liquid freshwater is in aquifers (00S4). Often aquifers are joined to surface waters that supply water to the aquifers. Also aquifers are often joined to rivers, lakes and oceans that receive water from the aquifer. So in a way, it can be misleading to speak of surface water problems and ground water problems as separate issues. Draining a swamp, for example, can reduce flows to aquifers down below. Some aquifers ("fossil water") are not connected to surface water and have no way of replacing any water drawn from them. Once these aquifers are drained they are lost forever. If water is extracted from an aquifer near an ocean too rapidly, saltwater may flow from the ocean into the aquifer - reversing the normal flow pattern. When an aquifer becomes composed of 2-3% seawater or more, the aquifer becomes useless as a source of freshwater useful for human consumption or irrigation. This is a serious problem in many coastal nations***.

(Dams) Filling of dam backwaters with erosion sediments also threatens water supplies for irrigation-, urban-, and industrial use. The world's dam backwaters are filling with sediment at 1%/ year (87M1) and several times that in the world's more densely populated regions. Sedimentation rates are now 8 times higher than in the mid-1960s (UNEP release (12/4/01)) so the 1%/ year rate from the mid-1980s may now be too low. A US Geological Survey study notes that new dam construction might increase the (global) dam supply (storage capacity?) by 0.33%/ year over the next 30 years (98S3). This suggests that global dam-backwater storage per-capita should drop 2%/ year in coming decades - even as per-capita water consumption rises twice as fast as the world's population (98S1). The supply of suitable dam sites is also shrinking, greatly increasing the cost of new dams - costs that are already so high that developing nations must finance them largely by increasing their staggering external debt.

(Glacier-Water) Half the world's population (about three billion people) depends on rivers starting from mountain glaciers as their freshwater source. Himalayan glaciers feed 7 major Asian rivers - the Ganges, Indus, Brahmaputra, Salween, Mekong, Yangtze and Huang He - ensuring a year-round water supply for two billion people (06H1). Shrinking glaciers, usually attributed to global warming, threaten the uniformity of the flows of these major rivers, and hence threaten the water supplies of these billions of people. The shrinking glaciers of the Andes Mountains in Latin America, the Rocky Mountains in the western US and the Alps of Europe probably account for the remaining one billion people whose water supplies are put at risk as a result of shrinking glaciers.

(Drip- or micro-irrigation) The water supply issue (and the salinity issue mentioned above) could be dealt with by greater use of "drip irrigation" and other "micro-irrigation" processes. They do not entail salt accumulation in the root zone (93P2) and, relative to furrow- or sprinkler irrigation, cut water use by 30-60% (96P1). One problem is the added capital required in developing nations where financial capital is already too scarce to even afford drainage tiles for avoiding salinity. Also, water supplies for irrigation are government-subsidized virtually worldwide, worsening the apparent (but not real) economics of drip irrigation. Typically on the order of 80-90% of the costs of "producing" water are government-subsidized. Perhaps for these two reasons, global use of drip irrigation accounts for less than 1% of the world's irrigated area (97P3).

(Water Conservation by using wastewater) Using wastewater is another water-conservation strategy. But salinity rises by 300-400 parts per million while passing through the urban circuit, and that salinity is not reduced by any of the usual sewage treatment processes (77A2). So more than once or twice through the urban circuit causes significant problems with salinization.

(Fallowing) Whether we are talking about the wheat fields of the US and Canadian Plains, the croplands run by shifting cultivators in most tropical rain forests, the grazing lands springing up all over the tropical portions of Latin America, or the irrigation systems threatened with salinization the world over, fallowing (idling) cropland for periods ranging from a year to several decades to permit the land to regain its past productivity is a common practice. Unfortunately fallow periods are shrinking in each of the environments listed above as a result of ever-increasing human pressures on the land to produce food and wood. The results are easily predictable. The land does not fully recover in the time allowed, so the long-term trend is toward ever-declining productivities. The name of the game is the same the world over - short-term gain, long-term pain.

(Desalination) Desalinated water costs about $800/ acre-foot, too expensive for irrigation by a factor of 10-30 or more (01R1). Also desalination plants are notoriously inefficient in terms of energy consumption. As a result they are very sensitive to increases in energy prices. Since irrigation uses (consumes) about 70% of the water that human-kind uses (consumes), it seems clear that desalination has little, if any, role to play in rendering water supplies sustainable unless there are major reductions in the cost of energy, or desalination technology can be made far more energy-efficient than it is today.

The above-mentioned sustainability problems are summarized below.

The combined magnitude of all these threats make if quite clear that irrigation systems, their water supplies, and hence the food they produce are non-sustainable. Further, the degree of non-sustainability is certain to increase, particularly in developing nations where water supplies get increasingly precarious, the financial capital needed to reduce salinity problems and increase water supplies becomes scarcer, external debt increases by $1 trillion every 10-15 years, and where high and growing population pressures on the land worsen numerous positive feedbacks.

*** Additional data on the sustainability issues described above are given below. Much more data can be found in "Irrigated Land Degradation: A Global Perspective," found on this website.

Go to this Chapter's Table of Contents ~ Go to home page of this website ~ Go to List of References ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")

Section [B] ~ BASIC FACTS ABOUT THE WATER-SOIL-SALT SYSTEM ~

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~

Section [C] ~ IRRIGATION SYSTEM BASICS ~

Use of Drip- and Micro-Irrigation in selected countries around 2000 (05B1)
Col. 2 = Area Irrigated by Drip- and other Micro-irrigation Methods in units of km2.
Col. 3 = Share (%) of Total Irrigated Area Under Drip or Micro-irrigation.

Country

Col. 2

Col. 3

Cyprus

360

90%

Israel

1250

66

Jordan

380

55

South Africa

2200

17

Spain

5630

17

Brazil

1760

6

US

8500

4

Chile

620

3

Egypt

1040

3

Mexico

1430

2

China

2670

under 1

India

2600

under 1

Total

28440

- -

The implication of the above table is that only a small percentage of the world's irrigated lands are being irrigated by drip- and other micro-irrigation methods. That percentage is about 1%.

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to List of References ~ Go to home page of this website

Section [D] ~ IRRIGATION SYSTEM GROWTH ~

Global irrigated area growth rate is down from 3%/ year during 1950 to the mid-70s, 2.0%/ year during 1970-82, and 1.3%/ year during 1982-94 (99P1). Per-capita irrigated area has declined 5% since 1978. Productivity of the world's irrigated land does not grow 1.3%/ year however. Yield degradation due to increasing salinization, water-logging, aquifer depletion, sea water intrusion into coastal aquifers, and water-supply reallocation to urban uses all detract significantly from the yields of irrigated lands. Growing financial demands on (and indebtedness of) developing nations, productivity losses to salinization, land abandonment due to salinization, aquifer depletion, surface water depletion, and reallocation of water to urban uses are all making it increasingly difficult to achieve net growth in irrigated area, output per unit area (yield) and dam storage capacity - not to mention per-capita growth. (Building and maintaining irrigation systems are heavily government-subsidized worldwide.)

Annual Renewable Water Resources (RWR) and Irrigation Water Requirements (03B1)

Column

1

2

3

4

5

6

Precipitation (mm)-

880

1534

181

1093

1252

1043

Internal RWR (km3)

3450

13409

484

1862

8609

28477

Net incoming flows (km3)-

0

0

57

607

0

0

Total RWR (km3)-

3450

13409

541

2469

8609

28477

Irrigation water withdrawal

Irrigation-efficiency-(1998)%

33

25

40

44

33

38

Irrig.water-withdrawal(1998)*

80

182

287

895

684

2128

~ ~idem as a % of RWR

2

1

53

36

8

7

Irrigation-efficiency-(2030)%

37

25

53

49

34

42

Irrig.water-withdrawal(2030)*

115

241

315

1021

728

2420

~ ~idem as a % of RWR

3

2

58

41

8

8

Note: RWR for all developing countries exclude regional net incoming flows to avoid double counting.
* km3

For the 93 countries used in the table above, irrigation water withdrawals are expected to grow by 14%, from the current 2128 km3/ year to 2420 km3/ year in 2030. The region expected to contribute the most to this increase is South Asia, e.g. India. This increase is low compared to the 33% increase projected in harvested irrigated area, from 2.57 million km2 in 1997/99 to 3.41 million km2 in 2030 (Table 4.8 in Ref. (03B1)) (03B1).

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to home page of this website ~ Go to List of References ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")

Section [E] ~ WATER SUPPLIES AND URBANIZATION LIMITING IRRIGATION ~ [E1]~ Global Data, [E2]~ Middle East and North Africa, [E3]~ U.S. [E4]~ Southern and Eastern Asia, [E5]~ Europe and Northern Asia, ~

Part [E1] ~ Global ~

Major categories of Global Freshwater Flows at a Glance:
Global precipitation rate: 110,000 km3/ year. 2/3 of this precipitation is evaporated (transpired) into the atmosphere, leaving 40,000 km3/ year to flow to the sea via rivers, streams and underground aquifers ("groundwater"). in northern North America, Europe and Asia, 55 rivers (with a combined flow of 5% of global runoff) are so remote that they have no dams on them. About 75% of the global runoff (i.e. 30,000 km3/ year) is in the form of floodwater. Large dams, which can hold 14% of the world's annual runoff, have increased the stable supply of water provided by underground aquifers and year-around river flow by nearly 1/3. This brings the world's total stable, renewable supply of freshwater to 14,600 km3/ year. Of this total supply, 12,500 km3/ year is within reach, geographically. So it is accessible for irrigation, industrial and household use (96P3).

Part [E2] ~ Middle East and North Africa ~

Part [E3] ~ U.S. ~

Part [E4] ~ Southern and Eastern Asia ~

Part [E5] ~ Europe and Northern Asia ~

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~
Go to home page of this website ~ Go to List of
References ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")

Section [F] ~ SALINITY AND WATERLOGGING EFFECTS LIMITING IRRIGATION ~ [F1]~ Global, [F2]~ Asian Sub-Continent, [F3]~ North America, [F4]~ Middle East - North Africa, [F5]~ Central Asia, [F6]~ Far East, [F7]~ Australia and Oceania, [F8]~ Latin America,

Part [F1] ~ Global ~
Large irrigated regions with serious salinity problems (85D1):

Irrigated Land Damaged by Salinization ((89P1), Table 2) (90P1)
(Areas in Column 2 are in units of 1000 km2.)

Region

Area

% of
irrigated
land

India

200

36%

China

70

15%

US

52

27%

Pakistan

32

20%

USSR

25

12%

Total

379

24%

World

602

*24%

* (by extrapolation)

Globally, the areas most affected by seawater intrusion into freshwater aquifers include Mexico, the northern portions of the Pacific and Atlantic coastlines (of the US), Chile, Peru and Australia. (07S2).

Irrigated Land Damaged by Salinization in the late 1980s (95G3)

Region

Area
(km2)

% of
irrigated land

India

70,000

17%

China

67,000

15%

Pakistan

42,000

26%

US

42,000

23%

Uzbekistan

24,000

60%

Iran

17,000

30%

Turkmenistan

10,000

80%

Egypt

9,000

33%

Subtotal

281,000

21%

World Est.

477,000

21%

Part [F2] ~ Asian Sub-Continent ~

Part [F3] ~ North America ~

Part [F4] ~ Middle East and North Africa ~

Part [F5] ~ Central Asia ~

Part [F6] ~ Far East ~

Part [F7] ~ Australia and Oceania ~

Part [F8] ~ Latin America ~

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~ Go to top of Section [F] (Salinity and Waterlogging Limiting Irrigation) ~ Go to home page of this website ~ Go to List of References ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")

Section [G] ~ IRRIGATION SYSTEM ABANDONMENT ~

About 70,000 km2 have been abandoned as salty wasteland in India (90P1).

Salinization has caused the abandonment of over 20,000 km2 of India's land (96G2). (Note the disparity between this estimate and the one above.)

India has abandoned a cumulative total of about 70,000 km2 of once-irrigated area (93U1) (94F1) (99F2).

Nearly 4 million acres (16,000 km2) of irrigated farmland is lost to excessive salt every year (01W2).

Research in the early 1990s puts the current loss of world farmland due to salinization at 15,000 km2/ year (Ref. 60 of (94K1)).

About 20-30,000 km2/ year of irrigated lands may be coming out of production due to salinization. (Average irrigated-area expansion in recent years has been about 20,000 km2/ year) (Ref. 12 of Ref. (96P1)).

David Seckler, Director General of International Irrigation Management Institute, believes that losses in irrigated areas may now exceed gains (97B2).

A Soviet soil scientist estimates that 200-250,000 km2 have been laid to waste over the centuries by mismanaged irrigation systems (76E1) (1978 Aspen Institute study in Ref. (82S1)).

A Soviet soil scientist estimates that 2000-3000 km2/ year out of a total world-wide irrigated area of nearly 2 million km2 pass from cultivation due to waterlogging and salinity (76E1) (1978 Aspen Institute study in Ref. (82S1)). More recent estimates are considerably higher.

Salinization severe enough to remove (irrigated?) land from production claims 15-25,000 km2/ year. (Ref. 52 of Ref. (96G2)).

Soviet agronomist Victor Kovda estimates a global rate of irrigation system abandonment of 10,000-15,000 km2/ year (Ref. 12 of Ref. (90B1)).

Waterlogging and salinization are sterilizing 10-15,000 km2/ year (85P1).

Aerial views of abandoned irrigation lands in the world's dry regions reveals vast expanses of glistening white salt-encrustation -- useless land (Ref. 21 of Ref. (89P1)).

Ref. (87P2) references a study (not named) claiming that as much irrigated land is being taken out of production due to salinization and waterlogging as is being bought into production by new irrigation schemes.

About 20,000 km2/ year of irrigated land are lost to salinity (Ref. 29 of Ref. (94P1)).

In Uzbekistan, 15,000 km2 of land were abandoned between 1950 and 1980 (500 km2/ year) due to high salinity (81F1). (To grow 1.0 kg. of cotton requires 660 gallons of water in Uzbekistan (81F1).) Some of this land may not have been irrigated.

Irrigation ceased on 29,000 km2 in central Asia during 1971-85 (2100 km2/ year) (Ref. 14 of Ref. (89P1)). This was 25% of the new area bought under irrigation in that same period (Ref. 11 of Ref. (90P1)).

Over 9300 km2 of irrigated farmland in China have come out of production since 1980 (1160 km2/ year) (Ref. 14 of (89P1)) (90P1). About 46% of China's 970,000 km2 of croplands are irrigated (90W1).

About 20-30% of Iraq's potentially irrigable land is unusable (76E1), i.e. has been converted to desert by salinization of irrigation projects (79S1).

Viewed from the air, vast areas of southern Iraq glisten with salt like new-fallen snow (85S1) (76E1).

Salt build-up has forced over 80,000 km2 in Iran out of production (96G2).

The FAO reports of salinity in the Euphrates Valley of Syria note that, on over 200 km2, salinity has caused the soil to be taken out of cultivation (Ref. 20 of Ref. (88S1)).

Hundreds of thousands of km2 throughout China are barren because of salinization. Some of it is natural. Some of it comes from old abandoned irrigation systems of the past (76E1).

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~ Go to top of Section [F] (Salinity and Waterlogging Limiting Irrigation) ~ Go to top of Section [G] (Irrigation System Abandonment) ~
~ Go to List of
References ~ Go to home page of this website

Section [H] ~ SURFACE WATER PROBLEMS ~[H1]~ Asian Sub-Continent, [H2]~ Eastern Asia, [H3]~ Middle East - North Africa, [H4]~ North America, [H5]~ Central Asia, [H6]~ Africa,

Some of the Major Rivers of the world that no longer reach the sea for at least parts of the year (99P1)

Yellow

(China **)

Ganges

(Asian sub-continent)

Indus

(Asian sub-continent)

Nile

(Northeastern Africa)

Amu Darya

(Central Asia)

Syr Darya

(Central Asia)

Chao Phraya

(Thailand)

Colorado

(Southwestern US)

Rio Grande

(Southern US)(02K2)

** See elsewhere in this review document

The data below is from a Table of Disappearing Lakes and Shrinking Seas http://www.earth-policy.org/Indicators/Water/2006_data.htm#fig4)

In developing countries, 90-95% of all sewage and 70% of all industrial wastes are dumped untreated into surface waters where they pollute usable water supplies (Ref. 15 of Ref. (02B2)).

Part [H1] ~ Surface Water Problems ~ Asian Sub-Continent ~

Both India and China rely heavily on major river systems that have their sources from the glacial melt of the Himalaya that is now under threat of global warming. Rapid glacial melt will not only cause short term flooding problems, but more importantly it will result in decrease of future water supplies for both nations (06H2).

Around 25% of India's agricultural production comes from land irrigated from over-exploited aquifers. Millions of wells have already gone dry (06P1).

The Gangotri glacier, which provides up to 70% of the water in the Ganges River during the dry summer months, is shrinking at a rate of 40 yards/ year, nearly twice as fast as two decades ago. According to a UN climate report, the Himalayan glaciers that are the source of the Ganges could disappear by 2030 as temperatures rise. In India, the Ganges River provides more than 500 million people with water for drinking and farming (07W1).

Part [H2] ~ Surface Water Problems ~ Eastern Asia ~

Part [H3] ~ Surface Water Problems ~ Middle East - North Africa ~

The Jordan River flows at 25% of the 1950 level, and is becoming increasingly saline (93L1).

Part [H4] ~ Surface Water Problems ~ North America ~

The Rio Grande River (second largest river in the US), by the time it reaches the Gulf of Mexico, has been reduced to a trickle compared to the pre-1962 average flow of 2.4 million acre-ft./ year. In February 2001 the Rio Grande River failed to reach the Gulf of Mexico (02K2). It still hadn't reached the Gulf of Mexico as of June 28, 2001. The Rio Grande used to be large enough for ocean-going ships for at least 10 miles from its mouth (Lynn Brezosky, Pittsburgh Post Gazette (6/28/01)).

Part [H5] ~ Surface Water Problems ~ Central Asia ~

The Aral Sea in Russia was once the fourth largest inland sea in the world. The sea will dry up by 2015 due to the damning of the rivers that feed it - all to grow cotton in arid Soviet Central Asia. The Aral Sea is a quarter of the size it was 50 years ago. It suffers from increased salinity that dry into huge salt plains that cause dust storms and spread disease and severely damage neighboring agriculture. Fishing has been wiped out, and agriculture is close to following it ("Russia's Aral Sea to Disappear Within 15 Years", News24.com (7/23/03)). Four decades ago, 60 km3/ year of water flowed into the Aral Sea. Now only 1-5 km3/ year trickles through. If no measures to save the Aral are taken, its area will decrease to 9,000 km2 (3500 mi2) from 41,000 km2 (16,000 mi2) in the mid-1990s. Shrinking of the Aral Sea might lead to large-scale migration. Given today's population explosion in the region, people may be unable to feed themselves from the remaining allotments of (fertile) land. Uzbekistan (24 million people, population growth 2%/ year) shares the dying sea with Kazakhstan. At least 10 million people might be involved in chaotic migration early in the 21st century (98B2). About 37 km3/ year of water are being withdrawn from the Aral Sea and surrounding ground water. Removable volume = 2500 km3 (94S1). The Amu Darya and Syr Darya Rivers once fed fresh water to the Aral Sea at 50 km3/ year. Irrigation diversions have reduced this input to 2-3 km3/ year, shrinking the Aral Sea from 64,500 km2 to under 30,000 km2 (95H1).

Part [H6] ~ Surface Water Problems ~ Africa ~

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~ Go to top of Section [F] (Salinity and Waterlogging Limiting Irrigation) ~ Go to top of Section [G] (Irrigation System Abandonment) ~ Go to top of Section [H] (Surface Water Problems) ~ Go to home page of this website ~ Go to List of References ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")

Section [I] ~ AQUIFER DEGRADATION ~ [I1]~ Global, [I2]~ Asian Sub-Continent, [I3]~ Eastern Asia, [I4]~ Middle East - North Africa, [I5]~ Sub-Saharan Africa, [I6]~Southeast Asia, [I7]~ North America, [I8]~ South America, [I9]~ Europe,

Part [I1] ~ Aquifer Degradation ~ Global ~

More than half the world's people live in countries where water tables are falling (07B1).

Average recharge rate for the world's aquifers: 0.007%/ year (Ref. 62 of Ref. (94K1)).

China, India, Saudi Arabia, North Africa, and the US over-pump and deplete aquifers at a rate of 160 billion cubic meters (tons?) annually. Since it takes it takes 1000 tons of water to produce 1 ton of grain (wheat), this 160-billion-ton water deficit is equal to 160 million tons of grain or one half the US grain harvest. 480 million of the world's 6 billion people are being fed with grain produced with unsustainable use of water. About 70% of the water consumed worldwide is used for irrigation, 20% by industry, and 10% for residential purposes. Migration to cities means that residential use of water triples due to indoor plumbing. If we decided abruptly to stabilize water tables everywhere by simply pumping less water, the world grain harvest would fall by 160 million tons, or 8% (World Watch (6/21/00)).

Scores of 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 US. Historically, water shortages were local, but shortfalls can cross national boundaries via the international grain trade. Water-scarce countries often satisfy growing needs of cities and industry by diverting water from irrigation and importing grain to offset resulting loss of production. Since a ton of grain equals (requires) 1000 tons of water, importing grain is the most efficient way to import water (02B1).

Groundwater over-pumping is widespread in central and northern China, northwest and southern India, parts of Pakistan, much of the western US, Northern Africa, the Middle East and the Arabian Peninsula. Ref. (99P1) believes that groundwater over-pumping may now be a bigger threat to irrigated agriculture than the buildup of salt in the soil.

Groundwater Depletion in Major Regions of the World, Circa 1990 (96P1):
US High Plains: This aquifer underlies nearly 20% of all US irrigated lands. Net depletion to date = 325 km3; Current depletion rate = 12 km3/ year.
California: Current overdraft = 1.6 km3/ year (About 2/3 of this overdraft is in Central Valley.)
Southwestern US: Water tables have dropped over 120 meters east of Phoenix. At current rate, water table will drop an added 20 meters by 2020.
Mexico City and Valley of Mexico: Pumping exceeds natural recharge by 50-80%.
Arabian Peninsula: Groundwater use nearly 3 times greater than recharge. Estimated reservoir lifetime at extraction rate projected for the 1990s = 50 years.
African Sahara: Current groundwater depletion rate is 10 km3/ year (3.8 km3/ year in Libya alone).
Israel and Gaza: Pumping from the coastal plain aquifer bordering the Mediterranean Sea exceeds recharge by 60%. Salt water has invaded the aquifer.
Spain: 20% of total groundwater use (1 km3/ year) is not sustainable.
India - Punjab (India's breadbasket): Water tables are falling 20 cm./ year across 2/3 of the Punjab.
India - Gujarat: groundwater levels declined in 90% of observation wells during the 1980s.
North China: Water table beneath Beijing has dropped 37 meters during the past 4 decades. North China's region of groundwater overdraft covers 15,000 km2.
Southeast Asia: Significant overdrafts have occurred in and around Bangkok, Manila and Jakarta. Over-pumping has caused land subsidence beneath Bangkok at a rate of 5-10 cm./ year for the past two decades.

Use of Drip- and micro-irrigation in selected countries around 2000 (05B1)
Col. 2 = Area Irrigated by Drip- and other Micro-irrigation Methods in units of thousands of ha.
Col. 3 = Share (%) of Total Irrigated Area Under Drip or Micro-irrigation.

Country

Col.2

Col.3

Cyprus

36

90

Israel

125

66

Jordan

38

55

South Africa

220

17

Spain

563

17

Brazil

176

~ 6

US

850

~ 4

Chile

62

~ 3

Egypt

104

~ 3

Mexico

143

~ 2

China

267

less than 1

India

260

less than 1

Total

2844

~ ~

The implication of the above table is that only about 1% percent of the world's irrigated lands are being irrigated by drip- and other micro-irrigation methods.

Part [I2] ~ Aquifer Degradation ~ Asian Sub-Continent ~

Farmers are driving Asian countries towards catastrophe, using tube wells that suck groundwater reserves dry, New Scientist says. Tens of millions of tube wells have been drilled over the past decade, many of them beyond any official control, and powerful electric pumps are being used to haul up the water at a rate that far outstrips replenishment by rainfall. In the case of India, smallholder farmers have driven 21 million tube wells into their fields and the number is increasing by a million wells per year. Half of India's traditional hand-dug wells have run dry, as have millions of shallower tube wells (04U3).

Villages in northwestern India have been abandoned because over-pumping depleted their aquifers (04U1).

In India's Indus basin as a whole, the rate of groundwater pumping is estimated to exceed the rate of recharge by 50% (p. 97 of Ref. (99P1)).

An estimated 25% of India's grain harvest could be in jeopardy from groundwater depletion (98S5).

In the north Indian state of Uttar Pradesh the number of water-short villages increased from 17,000 to 70,000 in two decades (98H1). Of 2700 water wells (tub wells?) supplied by the Uttar Pradesh government, 2300 wells have dried up (98H1).

Between 1946-1986 the water table in parts of Karmataka in India dropped 40 meters (Ref. 20 of Ref. (92P1)). In portions of the southern state of Tamil Nadu, ground-water levels have dropped 25-30 meters in a decade (Ref. 12 of Ref. (92P1)) (85B1) (90P1).

In Ludhiana District, one of 12 in India's Punjab where water tables have been carefully studied, the water table is dropping nearly 1 meter/ year (Ref. 18, Chapter 8 of Ref. (94B1)). Water tables are dropping by less than one to several meters/ year in much of India's Punjab (India's breadbasket), Haryana, Uttar Pradesh, Gujurat, and Tamil Nadu - states that contain a total of 250 million people (Ref. 16 of Ref. (95B1)).

Some 65% of Haryana India sits over salty groundwater (Ref. 38 of Ref. (96G2)).

In India's North Gujarat, the water table is falling by 6 meters/ year (07B1).

The Central Ground Water Board in New Dehli (India) reports that India's water table was lowered by over 25 ft. during 1983-95 (Pittsburgh Post Gazette (5/20/96)).

Delhi, India, is expected to run out of groundwater by 2015 at current rates of extraction (Environment News Service (3/22/01)).

India's 21 million water wells are powered by heavily subsidized electricity, yet they are lowering water tables at an accelerating rate. In some Indian states, half of all electricity is used to pump water (Ref. 9 of (05B1)).

In India's Tamil Nadu, (Population: 62 million people in southern India), falling water tables have dried up 95% of the wells owned by small farmers, reducing the irrigated area in Tamil Nadu by 50% over the last decade (07B1).

In the Pakistan's province of Baluchistan, water tables around the capital, Quetta, are falling by 3.5 meters/ year. A water expert with 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 (07B1)."

Observation wells near Pakistan's cities of Islamabad and Rawalpindi show a fall in the water table between 1982-2000 of 1-2 meters a year (07B1).

Water tables are plunging in the Pakistani state of Punjab, which produces 90% of Pakistan's food." ("Asia faces water catastrophe: scientists", PARIS (AFP) (8/25/04))

As a result of reduced flow in the Indus River in Pakistan, seawater is making intrusions into the land (surface?) and ground waters in coastal areas, particularly in the Thatta and Badin districts in the Indus Delta, making them saline. Once-fertile agricultural lands are becoming barren. (a speaker at a 2/8/02 conference "Population and Environment" organized by Pakistan's Sindh Population Welfare Department.)

Among the new refugees are people being forced to move because of aquifer depletion and wells running dry. Thus far the evacuations have been of villages, but eventually whole cities might have to be relocated, such as Quetta, the capital of Pakistan's Baluchistan province. Quetta (in Pakistan), originally designed for 50,000 people, now has 1 million inhabitants, all of whom depend on 2,000 wells pumping water deep from underground, depleting what is believed to be a fossil or non-replenishable aquifer. Quetta (in Pakistan) may have enough water for the rest of this decade (04B2).

In Pakistan's Indus Valley, groundwater is pumped at over 50% above the rate that would avoid water salinization (Ref. 30 of Ref. (96G1)). This salinization is presumably from seawater intrusion into coastal aquifers.

Part [I3] ~ Aquifer Degradation ~ Eastern Asia ~

A World Bank study indicates that China is over-pumping three river basins in the north - the Hai, which flows through Beijing and Tianjin; the Yellow; and the Huai, the next river south of the Yellow River (07B1).

Since 1000 tons of water produce one ton of grain, the shortfall in China's Hai River basin of nearly 40 billion tons of water/ 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 (07B1).

In the region around the Chinese city of Shijiazhuang (Population: 2.3 million, with a metropolitan area of 9 million), the water table is sinking about 4 ft./ year (07Y1). Some wells must now go down 600 or more feet to reach clean water. The region has more than 800 illegal wells (07Y1).

The North China Plain (population: over 200 million) depends on groundwater for 60% of its supply. Those aquifers will be drained within an estimated 30 years at their current rates of usage (07Y1).

The Yongding, Yishui, Xia and the Hutuo Rivers in China are "dead," i.e. water is no longer flows in them (07Y1).

In China's north plain, China's breadbasket, 30 km3 (1.059 trillion ft3) more water are being extracted each year by farmers than are being replaced by the rain, New Scientist said. Groundwater is used to produce 40% of China's grain. In June, the state paper China Daily admitted that China "may be plunged into a water crisis" by 2030 when China's population is scheduled to peak at 1.6 billion. The tube-well revolution, whose technology is adapted from the oil industry, has also swept water-stressed countries like Pakistan and Vietnam, where underground reserves are likewise being depleted, New Scientist says. "Vietnam has quadrupled its number of tube wells in the past decade to one million (04U3).

"Two-thirds of China's cities are now short of water and the very existence of some, such as Taiyuan, the capital of Shanxi, is threatened. All but a handful of the 300 tributaries that feed into the Hai River are now dry, with dire consequences for a population of 120 million people in the Hai river basin. But agricultural runoff from chemical fertilizers, industrial effluent, and urban waste has rendered the water in most of its reservoirs undrinkable. Across the whole of the North China Plain, where half of China's wheat is grown, 3.6 million wells have been sunk, mostly for irrigation. The aquifer below is being steadily drained and the water table is 90 meters below the surface and dropping by 3-6 meters/ year. Most of the 20 billion tonnes of urban sewage that China's expanding cities produce each year is dumped straight into rivers and lakes. China now produces as much organic water pollution as the US, Japan and India combined (03U3).

Aquifers beneath Taiuan China have dropped more than 300 feet. Today, about 48 million acres (194,000 km2) of arable land and 100 million people reside within China's Fen River basin (02U1).

Discharge of toxins from cities and factories has made China's Yellow River water unfit for irrigation and human consumption along much of its route. "Only 15% of Yellow River water is treated, and only 20% is recycled," said Vaclav Smil, a professor of geography at the University of Manitoba in Canada and an expert on China's water problems (02U1).

Over 65% of China's cities face severe water shortages (Environment News Service (3/22/01)).

The groundwater of Northern China will be exhausted in the next decade (03S1) (06H2).

The Gobi Desert in China is expanding by 4,000 square miles a year forcing people to leave because the aquifer below it was depleted (04U1).

In southwest Shanxi China, over-pumping has dropped water tables by 70 meters. Subsidence now affects about 92,000 km2 in northern China (Ref. 15 of Ref. (95B3)).

Crescent Moon Lake in northeast China is famous throughout China, attracting a million visitors/ year. In 1960 it was 10 meters deep. Now it is barely 1 meter deep. A 500-ft. high sand dune is encroaching on the lake and the adjacent town of 200,000 people and threatens both. Irrigation is lowering the top of the groundwater aquifer in the region by 40 cm./ year (07C2).

Deserts now cover 20% of China's land. Soon 40% of China's land could be lost under the migrating sand dunes being driven by increasingly frequent sandstorms (07C2).

Part [I4] ~ Aquifer Degradation ~ Middle East -North Africa ~

Over-pumping of aquifers in Iran is estimated at 5 billion tons (probably tonnes) per year. When Iran's aquifers are depleted, Iran's grain harvest could crop by 5 million tons (probably tonnes) per year - a third of Iran's current harvest (05B1).

In northern Iran's agriculturally rich Chenaran Plain the water table was falling by 2.8 meters/ year in the late 1990s. In 2001 the aquifer dropped 8 meters after a three-year drought and the new wells being drilled for irrigation and to supply a nearby city (02E1).

The World Bank reports that Yemen's water table is falling by 2 meters/ year or more (05B1).

In Yemen, (Population: 21 million), the water table under most of Yemen is falling by roughly 2 meters a year. In western Yemen's Sana'a Basin, the estimated water extraction of 224 million tons/ year exceeds the annual recharge of 42 million tons, dropping the water table 6 meters per year. World Bank projections indicate Yemen's Sana'a Basin -- site of the national capital, Sana'a, and home to 2 million people -- will be pumped dry by 2010. The Yemeni government has drilled test wells in the basin that are 2 km (1.2 miles) deep but they have failed to find water (07B1).

In Egypt, half of irrigated croplands suffer from salinization (05L1).

Iran's 70 million people face an acute shortage of water (02B1).

In Iran, thousands of villages have been abandoned because of spreading deserts (04U1).

Under the agriculturally rich Chenaran Plain in northeastern Iran, the water table was falling by 2.8 meters/ 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 8 meters. Villages in eastern Iran are being abandoned as wells go dry, generating a swelling flow of water refugees (02B1). (See http://www.earth-policy.org/Updates/Update15.htm http://www.earth-policy.org/Updates/Update15.htm for additional examples.)

Salinity in Israel's coastal aquifers is increasing by 2-3%/ year, and will double in 25 years. Aquifer salinization and contamination will be further accelerated by the proposed recycling of sewage (77A2). By 1985, 25% of water used in agriculture will be treated sewage. Desalination plants will be required well before 2000 because of aquifer salinization -greatly increasing the need for Arab oil (77A2). Decades of over-pumping have caused sea water to invade Israel's coastal aquifer. 20% of the aquifer is contaminated by salts or nitrates from urban or agricultural pollution (92P1).

Israeli water officials predict that 20% of its coastal wells may need to be closed within a few years due to salt-water intrusion (Ref. 8 of Ref. (96P1)).

Israel uses over 95% of the annually replenishable water available. By 1985, demand will reach 2 km3/ year, 25% more than the total water available from all natural sources (77A2). Water is being used with salinities as high as 10% that of sea water (3500 p.p.m.) (Brackish water) (77A2).

Gaza's aquifer is being severely over-exploited and salinized, to the extent that wells are going dry, water is becoming unpalatable, and in some areas, non-useable for irrigation (93L1).

While Israel and Jordan signed a treaty that included an agreement on water allocation, Jordan has, thus far, not yet received 50 million cubic meters (mcm) of water that Israel has conceded to Jordan (05U1).

Jordan's projected supply, demand and deficit (02J1) (in millions of m3/ year)

Year

Supply

Demand

Deficit

1995

882

1104

(222)

2000

960

1257

(297)

2005

1169

1407

(238)

2010

1206

1457

(251)

2015

1225

1550

(325)

2020

1250

1658

(408)

Government officials estimate that over 50% of Jordan's domestic water supplies are lost due to worn-out infrastructure and theft (Amman Jordan Times (4/20/99). The region is suffering one of its worst droughts in decades, and Israeli officials have announced they must cut the amount of water owed to Jordan under a water-sharing pact (UN Wire (4/20/99)).

Residents of Amman, the capital of Jordan, can turn their tap water on only one day a week," writes Senator Simon. "Syria faces problems almost as severe, and Israel has had to curtail water use dramatically (01S2).

Jordan and Yemen withdraw 30% more water from ground-water aquifers than is being replenished (98H1).

Syria's over-pumping of aquifers for irrigation has brought about saltwater intrusions into its coastal plains (96M2).

The growing population in Syria's capital, Damascus (now 3 million), has sucked the Baroda River nearly dry (91W1).

Lebanon's groundwater aquifers have dropped from 150 ft. below the surface to nearly 600 ft. (01P1).

Ground water in Gaza, which is estimated to have a potential of 65 mcm/ year is Gaza's only source for fresh water. At present, more than 100 million cubic meters (mcm) per year are pumped from these shallow aquifers that are resulting in the gradual invasion of seawater into Gaza Strip aquifers (See Table 2 above). Many hydrologists believe that the Gaza Strip aquifers have already passed the point of no return (05U1). Tests show increased salinity levels to, in some cases, greater than 1500 p.p.m. of chloride, making the water unsuitable for drinking (1993 data).

Irrigating the Negev desert has meant less water for the West Bank and Gaza. Near the city of Nablus, the village of Beit Dajan (population 3500) relies on 3 water tankers to bring water from wells in Nablus. The waiting time for a tanker load is one month. However, the 10 m3 delivered to each household is only enough for one week (02J2). A third of Palestine's residents survive off of food aid, and cannot afford $35 per delivery of water. A quarter of Palestinians lack access to potable water. Palestinian sources estimate Israeli water consumption is 4-10 times that of the Palestinians (02J2).

About 75% of groundwater used in agriculture on the Arabian Peninsula is not replenished (Ref. 33 of (96G2)).

Agricultural production threatens to drain Saudi Arabia's underground water resources within the next 10-20 years (90W1).

Fossil groundwater is mined for 75% of Saudi Arabia's water needs. Groundwater depletion has been averaging 5.2 km3/ year (92P1). If 80% of the reserve is exploitable, the supply will be exhausted in 52 years (Ref. 10 of Ref. (93P2)).

Over-reliance on a fossil aquifer to expand grain production contributed to a 62% drop in grain harvest between 1994-96 (97B2). Saudi Arabian grain production is plotted vs. time (1960-96) in (97B2).

Saudi Arabia imports over 70% of its grain (02B1). The Saudis tried to grow their own grain with water pumped from their aquifers, but eventually gave up on the idea.

Among the new refugees are people being forced to move because of aquifer depletion and wells running dry. Thus far the evacuations have been of villages, but eventually whole cities might have to be relocated, such as Sana'a, the capital of Yemen. The World Bank expects Sana'a, where the water table is falling by 6 meters/ year, to exhaust its remaining water supply by 2010. At that point, its leaders will either have to bring water in from a distant point or abandon the city (04B2).

The aquifer on which Sana'a, Yemen's capital (population: 900,000), depends is falling by six meters per year, and may be exhausted by 2010, according to World Bank estimates (05L1).

Yemen is a poor country with nearly 20 million people. Close to half of them live in poverty. Yemen's population is growing rapidly; by 2045, projections show it will have nearly as many people as Germany. Most of its population lives too far from the coast to make transportation of desalinated water practical. Most of Yemen's water is drawn from an aquifer that is likely to be depleted within a few decades. Yemen uses half of the water it draws from that reservoir to grow qat, a habituating stimulant (05W1).

In Yemen, (pop: 17 million) water tables are falling by roughy 2 meters/ year. In the basin where the capital, Sana'a, is, the water table is dropping 6 meters/ year, meaning the aquifer will be depleted by the end of the decade. Test drilling down to 2 km. failed to find any more water (00W5).

Yemen's water table is falling by 2 meters/ year and in Sana, the capital, it is falling by 6 meters/ year (02E1).

In Yemen, the water table under most of the country is falling by roughly 2 meters/ year as water use far exceeds sustainable yields of aquifers. Groundwater is being mined at such a rate that parts of Yemen's rural economy could disappear within a generation. In the basin where Yemen's capital, Sana'a, is located and where the water table is falling 6 meters/ year, the aquifer will be depleted by 2010. Yemeni's government has drilled test wells in the basin that are 2 km. deep, depths normally associated with the oil industry, but 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 (02B1).

Yemen imports nearly 80% of its grain (02B1). It doesn't have enough water to grow its own grain.

In Sana, the capital of Yemen, the water table is falling 20 feet a year. Quetta, in Pakistan, designed for 50,000 people, now has 1 million people depending on 2,000 wells depleting a non-replenishable aquifer (04U1).

Qatar aquifers will be depleted in 20-30 years at recent rates of ground-water withdrawal (UNEP, State of the Environment: National Reports (1987)).

North Africa (Egypt to Morocco) runs a water deficit of 10 km3/ year (99P1). Ref. (99P1) estimates a global water deficit of 200 km3/ year.

Libya's plan to extract 2.2 km3/ year from a desert aquifer will probably dry up the aquifer in 40-60 years (99P1).

Salt water is displacing fresh water in Libya's water table (Ref. 11 of (92P1)).

Part [I5] ~ Aquifer Degradation ~ Sub-Saharan Africa ~

Nine lakes in the Rift Valley including Nakuru, Elementaita, Naivasha, Baringo, Magadi and Logopeis could be extinct within the next 15 years. All the rivers that drain into these lakes are threatened because they rely on the Mau forest as their catchment area and this is being stripped of forest cover by logging for charcoal burning. ("Time to Act to Save Kenya's Dying Lakes," Kenya Times Newspaper (2/6/07)).

In Nigeria, 3,500 km2 becomes desert each year (04U1).

Part [I6] ~ Aquifer Degradation ~ Southeast Asia ~

In Manila (Philippines) where groundwater levels have fallen 50-80 meters due to over-drafts, seawater has flowed as far as 5 km. into the Guadalupe aquifer that lies beneath Manila (00S1).

Water demands in Thailand's Chao Phraya Basin exceed available supplies. Water supplies to Bangkok are not sufficient to alleviate severe over-pumping of ground water there (95P2) (99P1).

Water shortages were responsible for part of the 15% of the decline in Thailand harvested grain area during 1985-1995 (Ref. 36 of (96G2)).

In Jakarta (Indonesia), city dwellers extract groundwater at 3 times the rate of recharge. This has restricted water supplies to nearby rice farmers (Ref. 35 of Ref. (96G2)).

Part [I7] ~ Aquifer Degradation ~ North America ~

In the Gulf of California's states of Sonora, Sinaloa and Nayarit, agriculture consumes 80% of the fresh water available in the region, wasting 60% of that. The National Water Commission categorizes 41% of the region's aquifers as over-exploited (07N1).

Over-exploitation of the aquifers in the states of Baja California, Baja California Sur, and Sonora has caused saline seepage so bad that it has rendered formerly productive lands useless (07N1).

Farming on the Coast of Hermosillo (Gulf of California Region) is almost a lost cause. The level of the water table here, as well in the other coastal aquifers of Caborca and Guaymas, has dropped to 50 meters below sea level, so all these reservoirs are contaminated by salt-water intrusion. In some places, nothing grows (07N1).

In the US southern Great Plains, irrigated area has dropped by 24% since 1980 as wells have gone dry (05B1).

US ground water is being depleted 160% faster than its replenishment rate (97P1).

Groundwater levels in the US are declining beneath at least 61,000 km2 (82W1).

Over 20,000 km2 now irrigated (in the US) will have no remaining ground water by 2000 (84U1).

Removable volume of the Southwest US aquifer = 3000 km3 (94S1). Removable volume for California's Central Valley aquifer = 10,000 km3 (94S1). The corresponding extraction rates are 12, 10 and 13 km3/ year (94S1). Three large aquifers in North America are associated with limited recharge and significant mining: the High Plains (including Ogallala) Aquifer, the Southwest Aquifer, and the Central Valley (CA) aquifer (94S1). Total recoverable ground water in these American aquifers is equivalent to 4.6 cm. in sea level (Ocean area = 360 million km2). They are being mined at a rate of 0.1 mm (sea level)/ year, and have contributed 3.2 mm. of sea-level rise to-date (See Table 1 of Ref. (94S1)). Recharge rate of these three North American aquifers is 6.75, 1.05 and 0.78 km3/ year (94S1).

In the US southern Great Plains, irrigated area has dropped by 24% since 1980 as wells have gone dry (05B1).

Overdrafts amount to 50% of withdrawals in the Lower Colorado region of the Western US (82S1).

In central Arizona, ground-water levels are declining 2.1-3.0 meters/ year (82S1).

Tucson Arizona draws its water from the upper Santa Cruz- and Avra Valley Basin's groundwater. At present pumping rates, the Santa Cruz aquifer will be exhausted within 100 years (overdraft = 0.29 km3/ year) (81S1).

Some Tucson Arizona wells have dropped 110 ft. (34 meters) in the past decade (Ref. 6 of Ref. (81S3)), (81S1).

Water tables in some areas around Tucson Arizona have dropped over 50 meters. (85P1). Tucson pumps water at five times the rate nature replaces it (Ref. 7 of Ref. (81S3)), (81S1).

Groundwater over-drafts 0.681 km3/ year in the Santa Cruz Basin (of Arizona) are as severe as anywhere in the US. Even more water coming from the Central Arizona Project won't keep 2020 over-drafts under 0.617 km3/ year (81S1).

In aquifers of southern and central Arizona, 900 million acre-ft. (1110 km3) of recoverable water was stored in the upper 1200 ft. of sediments before development. 2.5 million acre-ft. (3.085 km3) of water enter and leave this aquifer yearly. From the beginning of development through 1980, 184 million acre-ft. (227 km3) of water has been pumped. Though part of this volume has been balanced by recharge, water levels have dropped by more than 400 ft. in some basins (p. 129 of Ref. (86S3)).

California irrigated land, in 1986, consumed (used?) 32 km3 of water (5 on pasture, 5 on Lucerne hay, 4 on cotton, 3 on rice, 2 on grapes) (01T1). This water went onto 37,000 km2 of irrigated land (3000 km2 was salt-affected.) Aquifer mining in California is 2.4 km3/ year which has caused a cumulative loss of aquifer storage of 25 km3 which is 47% of California's man-made storage of 53 km3 (01T1).

California over-drafts ground water at 1.6 km3/ year (15% of California's ground water use) (99P1).

Groundwater supplies 40% of total water consumption in California (81S2) (81S1).

In San Joaquin Valley's Westlands Water District, ground-water levels are dropping 3-6 meters/ year in 291 km2 (Ref. 108 of Ref. (81S3)).

In western San Joaquin Valley in California, some irrigation water is pumped from 1067 meters below the surface (81S1). About 1.85 km3 more water is pumped from the basin's aquifer than is naturally replenished (81S1) (79S2).

In Antelope Valley (north of Los Angeles California, and on the edge of Mojave Desert), ground-water levels are dropping 0.9 meter/ year, due mainly to urban demands (81S2), (Ref. 99 of Ref. (81S1)).

Mono Lake's level is dropping as water is drawn off to supply Los Angeles, 300 miles away (Ref. 100 of Ref. (81S1)).

Stockton California (pop. 190,000) draws 90% of its water from depleting wells (89C1).

In parts of San Joaquin Valley and Tulare Basin (California), ground-water levels have declined nearly 400 ft. (86S3).

Albuquerque New Mexico, whose underground reserves were until recently vastly overestimated, could dry up by 2050 (01R1).

In the SW corner of Kansas are 10,000 wells on 8000 mi2 (20,700 km2). They withdraw 3.5 million acre-ft./ year (4.32 km3/ year) from the Ogallala (82M1). Since 1940 the saturated thickness in half of the southwestern Kansas Ogallala has declined 11% or more (82M1). The Arkansas River dries up permanently somewhere between the Colorado state line and Deerfield, 50 miles to the east (82M1). In Groundwater Management District 3 along the western reaches of the Kansas Ark River, it has been decided that a 40% depletion of the Ogallala Aquifer in the next 25 years is acceptable, and permits are granted accordingly (82M1).

The Ogallala Aquifer depletion rate is 12 km3/ year (99P1).

The Ogallala Aquifer is being depleted at a rate 20 times the rate of natural replenishment (93G1).

The Ogallala Aquifer in the US supplies 22 km3 of water/ year to a land area of 53,000 km2. Aquifer mining of the Ogallala aquifer is 18 km3/ year (01T1).

The Ogallala Aquifer, which stretches from the Texas Panhandle to South Dakota, is believed to have contained 4 trillion tons of pristine water. It is now mined by over 200,000 wells that pull out 6838 billion gallons/ year, 14 times faster than the recharge rate. Since 1991 the Ogallala Aquifer's water table has dropped three feet/ year. By some estimates, more than 50% of the Ogallala Aquifer's water is gone (02U3).

Rain recharges the Ogallala Aquifer at 0.006 meter / year. Water is being pumped from the aquifer at 1.5 meters/ year (80J1).

The Ogallala Aquifer is being drawn down 15-18 times faster than nature is replacing it (80F1). The Ogallala Aquifer supports irrigated agriculture on more than 44,500 km2 of arid land (Ref. 24 of Ref. (81S2)). Mean thickness of the Ogallala Aquifer is 700 ft. (p. 31 of Ref. (86S3)).

About 20% of US irrigated croplands is supported by water mined from the Ogallala Aquifer (85P1).

The Ogallala Aquifer is now half depleted under 9,000 km2 of Kansas, New Mexico, and Texas (85P1).

Depletion of the Ogallala Aquifer in the southern Great Plains, and diversion of irrigation water to sunbelt cities in Arizona, California and Florida have led to a 3% decline in US irrigation area since 1978 (85B1).

In West Texas, 63,000 irrigation wells pump 4900-9800 m3/ year of water from the Ogallala Aquifer from depths of 30-90 meters to irrigate 21,000 km2 (70P1). Since 1949, average pumping lift in Hale Co. Texas has increased from 12 to 30 meters (70P1).

In some areas of the Rio Grande River basin (Mainly in Texas) groundwater pumping has reduced or even eliminated spring flow or allowed the infiltration of saline water into the fresh water zones. Many observers have predicted that, at current pumping rates, the Hueco Bolson aquifer (under El Paso and Cd. Juarez) may run dry for all practical purposes in 20 years (02K2).

The underground aquifer supplying the Juarez Mexico-El Paso Texas area will be exhausted in 15-25 years ("The Border" (http://www.pbs.org/kpbs/border/) A two-hour documentary, aired on PBS 9/23-24/99).

In Gaines Co. Texas groundwater is consumed at twice the rate of natural recharge. The entire billion-$ agricultural economy of the Texas High Plains is built on the over-draft of water from the Ogallala Aquifer (Ref. 362 of Ref. (81S1)).

Over-drafts in Texas amount to 78% of groundwater withdrawals, 30% in the Rio Grande Region (82S1).

As of 1990, 24% of the Texas portion of the Ogallala Aquifer had been depleted - a loss of 164 km3 (92P1).

Nearly 12% of the nation's corn, cotton, grain sorghum and wheat, valued as high as $2.8 billion are watered by the Ogallala Aquifer (80F1).

The Ogallala Aquifer holds 4000 km3 of water (95G1).

Ogallala groundwater levels in Kansas and Western Nebraska have dropped as much as 60 ft. Water levels dropped 16 ft. during 1952-75. If all water developments planned for the Platt River are carried out, the Platt River will be dry in 35 years (79A1).

During 1982-92, farmers drawing water from the Ogallala Aquifer lost three times more irrigated area than they gained. Five High-Plains states and 3 in the western US cut irrigated area by nearly 10% over 1982-92 (Ref. 11 of Ref. (96G1)).

Sidney Nebraska groundwater levels dropped 22 ft. during 1970-78 (79A1).

In the High-Plains-Ogallala Aquifer study, experts predicted the aquifer has about 30 years of life remaining at the present rate of development (Ref. 12 of Ref. (79A1)).

The High Plains Aquifer underlies 174,000 mi2 (451,000 km2) in CO, KS, NB, NM, OK, SD, TX and WY. 134,000 (347,000 km2) of this is the Ogallala Aquifer (86S3).

Recharge rate of the US High Plains Aquifer is 0 to 41 mm./ year (Ref. 9 of Ref. (94S1)). Removable volume of High Plains Aquifer = 4000 km3 (94S1).

About 20% of the irrigated land in the US, and 30% of the groundwater used for irrigation, comes from the High Plains Aquifer. In 1980, 18 million acre-ft. (22.2 km3) were pumped from this aquifer to irrigate 14 million acres (p. 30 of Ref. (86S3)).

Average recharge of the High Plains Aquifer System is 5.7 million acre-ft/ year (7.03 km3/ year). 80% of this recharge occurs north of 39o latitude (p. 31 of Ref. (86S3)). Average saturated thickness of the High Plains Aquifer System is 200 ft.; 46% has less than 100 ft.; 5% has over 600 ft. (p. 34 of Ref. (86S3)). Total volume of drainable water in the High Plains Aquifer in 1980 was 3.25 billion acre-ft. (4011 km3) - 65% in NB, 12% in TX, 10% in KS, 4% in CO, 3.5% in OK; 2% in SD, and 1.5% in NM (86S3).

In Texas, Oklahoma, and Kansas the water table has dropped by more than 100 feet (02U6).

Ciudad Juarez (Mexico), across from El Paso, Texas, has soared beyond a million inhabitants, typical of northern Mexico's growth. It could run out of water as early as 2006 (01R1).

In areas such as the high plains of West Texas, underground water supplies are being steadily depleted ((76E1) p. 135).

In parts of Ft. Worth-Dallas Metro-area, water tables have fallen over 120 meters in the last 25 years (Ref. 23 of Ref. (85P1)).

In Texas, water tables are falling 15 cm./ year beneath 15,400 km2 which is 72% of the irrigated area of Texas (90P1).

In the Texas high plains, irrigated area is expected to drop 45% by 2000 even if conservation cuts water use by 20% (80F1).

Groundwater supplies 75% of total water consumption in west Texas, 62% in Arizona (81S2) (81S1).

Over-drafts in Texas amount to 78% of groundwater withdrawals, 30% in the Rio Grande Region (82S1).

Between 1978-1982, irrigated land in Texas dropped by 20% (and by 18% in Oklahoma (85P1)).

The Columbia Plateau Basalt regional aquifer system has experienced declining water levels of as much as 20 ft./ year and sodium enrichment of its waters (86S3).

Along the Atlantic coast of the US, seawater seeps into aquifers from Cape Cod to the southern tip of Florida (01R1).

In the U.S. Southeastern Coastal Plain Regional Aquifer System, precipitation = 50"/ year (p. 206 of Ref. (86S3)). Over-land runoff = 7"/ year; evapo-transpiration = 35"/ year; recharge to aquifers = 8"/ year (1" of that to the deeper aquifers). In places, municipal and agricultural use has resulted in local water level declines of up to 100 ft. of pre-development levels (p. 206 of Ref. (86S3)).

Across the southern U.S. are water shortages that, in some instances, approach crisis proportions (Ref. 12 of Ref. (85H1)). It is not known whether this is a surface-water problem or a groundwater problem.

In several of the 11 states of the US Southeast, water pumping for irrigation has lowered sub-surface water levels by 50 to several hundred feet (85H1).

About 40,000 km2 of US irrigated land are watered by over-pumping ground water (20% of US irrigated acreage) (Ref. 11 of (92P1)).

In the Grand Prairie area of eastern Arkansas, irrigation pumping since the 1930s has caused water level declines of more than 18 meters in the Mississippi River Alluvial aquifer (Ref. 27 of Ref. (85H1)).

Alarmed by increasing reports of suburban wells running dry, the Northeastern Illinois Planning Commission looked into the problem, releasing a report earlier this year forecasting water shortfalls by 2020. The 6-county Chicago metro area is projected to add 1.3 million people by 2020. The lesson from Chicago, say water experts, is that the days of cheap, easy water are over in the US. If Chicago has to scramble for water, then fierce competition over water can break out anywhere (01L1).

In Mexico's agricultural state of Guanajuato, the water table is falling by 2 meters or more a year. At the national level (in Mexico), 51% of all of Mexico's water extracted from underground is from aquifers being over-pumped (07B1).

Guadalajara (in Mexico) faces water rationing and a growing crisis. For more than a decade, Mexico has not invested in water development. Now its aquifers are polluted or dry, municipal drainage systems waste 40% of the water and every city with a population over 100,000 has problems finding clean water. Water was rationed after Guadalajara's main water source, Lake Chapala, fell to low levels. Guadalajara added no new water sources for 13 years but the population increased by 1 million. Every city of 100,000 population has a drinking-water problem. The 97 aquifers that supply half of Mexico's drinking water are overexploited and in decline. One-sixth of Mexico's population has no running water. The president pledged to spend $250 million to preserve the Lake Chapala-Rio Lerma basin. But still Guadalajara stands out. It added no sources to its supply since 1991 while the population grew 30%, drinking water is increasingly fouled by industrial pollution. The Rio Santiago River is among Mexico's most polluted and opponents say the government is underestimating the cost of purifying the water. An engineer with the water commission, says that the water can be made potable and the construction and operating cost of the Arcediano dam, a projected $300 million is 40% less than the Rio Verde alternative (04U2).

Since 1970 Lake Chapala in Mexico's state of Jalisco has lost 80% of its water. The lake is fed by Rio Lerma that passes through several hundred miles of (semi)arid farmland supporting 11 million people in its watershed. Most of the water is diverted to irrigation systems that use water-wasteful techniques. Also the manufacturing center, Guadalajara, draws on the lake as its principal source of water (03C2).

The Rio Conchos is being diverted for agricultural use in Mexico. Soon in Big Bend National Park it will be dry during part of the year (03K1).

In Mexico's state of Guanajuato, the water table is falling by 1.8-3.3 meters/ year (02E1).

In Alamos, Mexico, ancient aquifers are pumped at five times the sustainable (recharge) rate (02R1).

In 25 years, Mexico's total number of areas of over-exploited aquifers has tripled to 96. Seawater has polluted 17 others because of over-pumping. Toxic seepage is spreading fast (02R1). Mexico City, built eight centuries ago atop vast lagoons, cannot supply water for its 22 million inhabitants. Less than half of Mexico City's wastewater is treated. The rest sinks into underground lakes or flows to the Gulf of Mexico, turning rivers into sewers (02R1). Hydrologists estimate that only 27% of Mexico's surface water is clean enough for simple treatment. Some 49% requires complex and expensive equipment. The rest (24%) is too poisonous for any practical use (02R1). Outmoded and neglected water systems in Mexico are crippled further by theft from illegal connections. In most cities, more than 50% of piped water is lost to leakage (02R1). Well over half of Mexico's irrigation water is lost to evaporation or seepage. Water-sharing systems often fall apart in Mexico because local officials flout the rules for bribes or personal ties (02R1). Under agreements worked out decades ago, Mexico receives a fixed minimum of the Colorado's normal flow, more in rare years of excess. But the Rio Grande requires complex negotiation. Mexico can borrow extra Rio Grande water, but must pay it back. President Vicente Fox has promised to pay the debt, which amounts to enough to put the state of Delaware under a foot of water. But with Mexico already so short of water, it is not clear how he might do that (02R1). Meanwhile, because of drought and rising demand, farmers on both sides are demonstrating on country lanes and in city streets with a hostility not seen before (02R1).

Mario Cantu Suarez, a deputy director of Mexico's National Water Commission, said 35 cities must shrink dramatically unless more water can somehow be found. Parts of Mexico are dying, with fields poisoned by salt and village wells running dry. 85% of Mexico's economic growth, and 75% of its 100 million people, are in the north, and the bulk of the water is far to the south. It costs too much to pipe over mountains or to desalinize far from the sea. To supply the north's new industries and farms, Mexico depends on much of the same water that is needed in California, Arizona, New Mexico and Texas (02R1).

In Mexico - home to 104 million people and growing by 2 million/ year - 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/ year (02B1).

Some measured surface-subsidence data (56T1):
Mexico City: 1.6"/ year in 1937, 5.5"/ year in 1948, 11.5"/ year in 1954.

Ground water pumping in Mexico City exceeds recharge by 50-80% (Ref. 11 of (93P2)).

Go to home page of this website ~ Go to List of References ~
Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")

Part [I8] ~ Aquifer Degradation ~ South America ~

Ref. (70C2) cites evidence of serious over-drafts of groundwater (mainly for irrigation) in Ica Valley, Piura, Chicama, Ilo, and La Yarada (all along Peru's arid Pacific coast).

Colombia's water supply could be reduced by up to 40% within 50 years. In Colombia's paramo, the Andean mountain moorland, over-farming has reduced the soil's ability to hold water that later drains into lowland rivers. This typically translates into erosion and a loss of soil organic matter content.
58% of the Colombian paramo is gone.
75% of the rest of Colombia's paramo could disappear in 15 years.
27% of high Andean forests (in Colombia) have been cut down ("Colombia's Water Supply is Threatened", Planet Ark (6/3/02)).

Part [I9] ~ Aquifer Degradation ~ Europe ~

The La Mancha aquifer in Spain is being consumed at a rate of 2-3 times its rate of recharge (01U1).

In Spain, irrigation of fields on which wheat, maize and vegetables are grown has reduced groundwater levels by five meters (01U1).

About 60% of Spanish coastal aquifers are contaminated by seawater intrusion. (Freshwater contaminated by 5% seawater cannot be used for purposes such as human use, agriculture or farming.) (07S2).

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~ Go to top of Section [F] (Salinity and Waterlogging Limiting Irrigation) ~ Go to top of Section [G] (Irrigation System Abandonment) ~ Go to top of Section [H] (Surface Water Problems) ~ Go to top of Section [I] (Aquifer Degradation) ~

Section [J] ~ GLOBAL-SCALE WATER SCARCITY ~

(Water scarcity is defined as less than 1000 m3 of water available/ person/ year, while water stress means less than 1500 m3 of water is available/ person/ year (99S1).)

More than half the world's 500 mightiest rivers have been seriously depleted. Some have been reduced to a trickle in what the UN warned is a "disaster in the making" (06L1).

Few countries, if any, have well-functioning systems for allocating water between competing demands and needs (05F2).

"Global Water Outlook to 2025: Averting an Impending Crisis," presents three alternative future scenarios for global water supply and demand, and food production and consumption, based on the results of the IMPACT computer model. Only one of the three scenarios is given below (02I1).

Business-as-Usual Scenario Projections:

In the last 50 years, global demand for water has tripled with the rapid worldwide spread of powerful diesel and electrically driven pumps that can pump ground water (02E1).

When the Soviets decided, after a poor harvest in 1972, to import grain rather than tighten their belts, world wheat prices climbed from $1.90/ bushel in 1972 to $4.89 in 1974 (02B1). The point here is that 1 ton of wheat requires 1000 tons of water and 1 ton of wheat is more transportable than 1000 tons of water. So water shortages translate readily into wheat shortages and the demand elasticity of wheat is very low. (See below)

70% of world water use, including all the water diverted from rivers and pumped from underground (aquifers), is used for irrigation. 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 over-pumping of its aquifers, China is developing a grain deficit. (But it is not yet (as of 2002) a net importer.) After rising to an historical peak of 392 million tons in 1998, grain production in China 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 China's grain reserves. But if this continues, China will be forced to turn to the world grain market (02B1).

Scores of 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 US. Historically, water shortages were local, but shortfalls can cross national boundaries via the international grain trade. Water-scarce countries often satisfy growing needs of cities and industry by diverting water from irrigation and importing grain to offset resulting loss of production. Since a ton of grain equals (requires) 1000 tons of water, importing grain is the most efficient way to import water (02B1).

The assessment in an unclassified CIA report called "Global Trends 2015," makes a number of predictions about the global political landscape. In terms of global resources, the report concludes that by 2015, nearly half of the world's population - more than 3 billion people - will be in countries lacking sufficient water. The 70-page report is one result of an unusual 15-month collaboration between the National Intelligence Council, a sort of analytical think tank of senior intelligence officials that works alongside the CIA, and dozens of outside scientific, diplomatic and corporate experts (00U1) (00C1).

In 2015 nearly 3 billion out of the estimated global population of 7.5 billion people will find it difficult or impossible to find water for food, industry and personal needs. Today's trouble zones are Afghanistan, Pakistan, India, China, Iran, Israel, Jordan, and Syria. According to John Gannon, a former assistant director of the CIA and former chairman of the National Intelligence Council, water scarcity now constitutes "a significant issue in security" as water shortages "encourage refugee movements which, if they spill over into other countries, can engage us." "If people don't have water, they can't live. They are going to move or they are going to die." According to the CIA report "Global Trends 2015" none of the proposed solutions - importing water, water conservation, expanded use of desalinization of seawater, or developing genetically modified crops that use less water or more saline water - will be sufficient to substantially change the outlook for water shortages in 2015 (01U2) (00C1).

In 2001, 2.3 billion people (about 38% of the world population) lived in water basins that are at least stressed; 1.7 billion people live in water basins where scarcity conditions prevail. By 2025 these numbers will be 3.5 billion and 2.4 billion respectively (02B2).

By 2025, 12 more African countries will join the 13 that already suffer from "water stress" or "water scarcity" (99S1). (See definition of terms above.)

Population growth and economic progress will, based on current trends, lead to nearly 50% of people in Africa living in countries facing "water scarcity" (or 'water stress') within 25 years (99S1).

A USGS study notes that new dam construction might increase that supply by 0.33%/ year over the next 30 years, but population is expected to grow at four times that rate (98S3). It is not clear whether the US Geological Survey study accounts for the rate of filling of dam backwater storage volume with sediments - about 1.0%/ year (Some estimates are larger.) The term "supply" might refer to storage capacity - but then again it might not.

Hydrologist Malin Falkenmark of Sweden, have calculated that, in 1990, 28 countries containing 335 million people faced chronic water stress or outright scarcity. By 2025, water shortages may plague up to 52 countries, affecting as many as 3.2 billion people; roughly 40% of the projected global population (98H1).

Global water consumption rose six-fold from 1900-95, more than twice the rate of population growth (Environment News Service (3/22/01)). This suggests that per-capita water consumption has more than tripled during 1900-1995. Much (most?) of this tripling is a result of increasing per-capita irrigated acreage.

China, India, Saudi Arabia, North Africa, and the US over-pump and deplete aquifers at 160 km3 annually. Since it takes it takes 1,000 tons of water to produce 1 ton of grain, this 160-billion-ton water deficit is equal to 160 million tons of grain, or 50% of the US grain harvest. 480 million of the world's 6 billion people are being fed with grain produced with unsustainable use of water. 70% of the water consumed worldwide is used for irrigation, 20% by industry, and 10% for residential purposes. Migration to cities means that residential use of water triples due to indoor plumbing. If we decided abruptly to stabilize water tables everywhere by simply pumping less water, the world grain harvest would fall by 160 million tons, or 8% (World Watch (6/21/00)).

15.6 million people and 13.1 million farm animals face water shortages in China (South China Morning Post (5/24/00)).

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~ Go to top of Section [F] (Salinity and Waterlogging Limiting Irrigation) ~ Go to top of Section [G] (Irrigation System Abandonment) ~ Go to top of Section [H] (Surface Water Problems) ~ Go to top of Section [I] (Aquifer Degradation) ~ Go to top of Section [J] (Global Scale Water Scarcity) ~ Go to home page of this website

Section [K] ~ SOME GLOBAL WATER INVENTORY- AND TRANSFER BASICS ~

Global precipitation rate: 110,000 km3/ year. 2/3 of this is evaporated (transpired) into the atmosphere, leaving 40,000 km3/ year to flow to the sea via rivers, streams and underground aquifers ("groundwater"). 55 rivers in northern North America, Europe and Asia, with a combined flow of 5% of global runoff, are so remote that they have no dams on them. 75% of the global runoff is in the form of floodwater. Large dams, which can hold 14% of the annual runoff, have increased the stable supply of water provided by underground aquifers and year-around river flow by nearly 1/3, bringing the total stable, renewable supply of water to 14,600 km3. Of this total, 12,500 km3 is within reach, geographically and so is accessible for irrigation, industrial and household use (96P3).

In any given year, 54% of the available freshwater is used (01M1).

Only 2.5% of all water on Earth is fresh water. Of that, 0.5% is accessible to people through ground water and surface water supplies (01M1).

Water evaporated from ocean/ sea/ river surfaces takes about 10 days to fall again as rain (01P1) (90B2).

About 160 km3 of water evaporates each day from the land surfaces of the Earth (58,440 km3 / year) (a removal rate of 39 cm. depth of water/ year from the land if the removal were the same from each unit area of land) (01P1) (90B2).

About 0.001% of the Earth's total water resides in the atmosphere at any point in time - enough to deposit about 1 inch of rain if it fell uniformly throughout the world (01P1) (90B2).

Every 3100 years a volume of water equivalent to all the oceans passes through the atmosphere (01P1) (90B2).

Total volume of fresh water on land and in the atmosphere: 8.5 million km3. 8.3 million km3 are ground water, 0.126 million km3 occur in lakes, rivers and streams. The balance (0.074 million km3) is atmospheric vapor, soil moisture and seepage (80C2) (Water Resources of the World data). This breakdown appears to neglect freshwater in glaciers and ice caps, e.g. Greenland.

Global Water Resource Summary (03W1) (UNESCO; Internationally Shared Aquifer Resources Management)

Oceans

96.50%

Fresh water

2.53%

Brackish water

0.97%

Total Water

100.00%

Global Fresh Water Resource Summary (03W1) (UNESCO: Internationally Shared Aquifer Resources Management)

Glaciers/ permanent snow

69.600%

Ground water

30.100%

Lakes, marshes, swamps

0.290%

Soil Moisture

0.050%

Atmosphere

0.040%

Rivers

0.006%

Living Organisms

0.003%

Total Fresh Water

100.089%

Of the world's water supply, 97.5% is salt water. Most of the remaining 2.5%, fresh water, is in glaciers and ice caps, unavailable for use by living things. 0.77% is in lakes, rivers, swamps, and aquifers, or in the atmosphere, or in soils and plant tissues (98S3).

Only 2.5% of the world's water is not saline. Of that, 2/3 is locked up in ice-caps and glaciers. 20% of what is left is in remote areas and virtually all of the rest - monsoons, storms and floods - comes at the wrong time and place. (Agence France Presse "Major Water Crisis Looms" (3/13/00)) (World Commission on Water for the 21st century data).

About 20% of the water running to the sea (presumably via either surface water runoff or via aquifers) is too remote to supply any cities or farming regions. About 50% runs off to the sea in the form of floods. Much of the remainder occurs in regions where abundant rainfall makes irrigation unnecessary (96P2).

Average recycling time for ground water: 1400 years (00S1).

Average recycling time for river water: 20 days (00S1).

About 97% of the planet's liquid freshwater is in aquifers (00S1).

By 2025, water will be lost through evaporation from reservoirs (dam backwaters) at a rate of 300 km3/ year, vs. 200 in 2000 (03U1). Other data (See soil and croplands degradation review (07S1)) says that reservoirs behind dams lose 10% of their water per year. The volume of water in pools behind the world's dams is about 6000 km3.

In the mid-1990s, the storage capacity of large dams was 5,500 km3, of which 3,500 are actively used in regulation of run-off (96P2). (See the soils and croplands degradation review for much more data on dams (07S1).) In the soils/ croplands degradation review it talks about a capacity of the world's dams being 6000 km3 or more, but this figure could include both large and small dams.

Renewable Fresh Water Resources (1998) (in units of 1000 cubic yards/ capita/ year) (Wall Street Journal (6/3/99)) (WRI data (98B3))

Canada

122.7

Brazil

40.8

Russia

37.8

Indonesia

15.9

US

11.7

China

2.9

Canada is said to have 20% of the world's fresh water, but Canadian officials contend that, if glaciers and polar ice caps are ignored, Canada has only 9% of the world's renewable fresh water resources. British Columbia and Alberta have banned exports of bulk fresh water, and the Canadian government is planning to (Wall Street Journal (2/11/99)). (Note: Global trade rules say that, if you start exporting water, you are not allowed to stop. This may be the reasoning behind Canada's water trade policy.)

Global Runoff and Population, by Continent, 1995 (96P3).

Region

Runoff
km3/year

Share of
Runoff

Share of
Population

Europe

3240

8%

13%

Asia

14550

36%

60%

Africa

4320

11%

13%

North & C. America

6200

15%

8%

South America

10420

26%

6%

Australia, Oceania

1970

5%

<1%

Totals

40700

101%

100%

Global runoff estimates (via surface waters and aquifers) range from 33,500-47,000 km3/ year. The estimate of L'Vovich et al (Ref. 6 of (96P2)) (40,700 km3/ year) is in the middle of the range (96P2). More details on this are in the Literature Review of soils and croplands degradation (07S1).

Average runoff worldwide: 39,500-42,700 km3/ year ((99F1), p. 31) ((97S1), p. 13). Most of this runoff occurs in flood events or is otherwise not accessible to human use. Only 9000 km3/ year is readily accessible to humans, and an added 3500 km3 is stored in reservoirs ((97W1), p. 7). The reservoir storage datum may be obsolete. More recent figures for reservoir storage are about 6000 km3 (See Soils and Croplands Degradation Review (07S1)).

Evaporation lifts 500,000 km3/ year of water into the atmosphere - 86% from oceans, 14% from land (92P1).

Continents lose water at 70,000 km3/ year from evaporation, but gain 110,000 km3/ year through precipitation. The net, 40,000 km3/ year = 7400 m3/ person (92P1). 2/3 of this 40,000 km3 runoff in the form of floods, leaving 14,000 km3/ year of stable surface water supply (92P1).

The inaccessible remote flows of the Amazon (95% of total flow = 5387), Zaire-Congo (50% of total flow = 662) and northern tier undeveloped rivers (95% of total flow = 1725) amounts to 7,774 km3/ year (19% of total annual run-off). This leaves 40,700-7,774 = 32,900 km3/ year of accessible river flow (96P2). About 11,100 km3/ year of global run-of (27% of total) is renewable groundwater and base river-flow (Ref. 6 of Ref. (96P2)). So 0.27x 7,774 = 2100 km3/ year is renewable groundwater and base river flow in inaccessible remote areas (96P2).

Arid and semi-arid zones of the world receive 2% of the world's runoff, even though they occupy 40% of the terrestrial area ((97W1), p.7). Transpiration losses are a large fraction of rainfall in arid and semi-arid regions.

For 82% of the world's agro-ecosystems, rainfall is the sole source of water for agricultural production ((00W1), p. 66).

Some 40% of developing-world farmers depend upon regular flows of rivers and streams to irrigate their croplands (96M1).

(The role of glaciers in providing freshwater) Half the world's population depends on rivers starting from mountain glaciers as their freshwater source. Himalayan glaciers feed 7 major Asian rivers - the Ganges, Indus, Brahmaputra, Salween, Mekong, Yangtze and Huang He - ensuring a year-round water supply for two billion people (06H1). But the Himalayan glaciers are retreating. Recently the Chinese academy of sciences announced that the Tibetan glaciers are shrinking by 7%/ year. The annual loss of ice is equivalent to the annual flow of China's Yellow River. In the Ganges River alone, this loss of glacier melt water could reduce July-September flows by two thirds, causing water shortages for 500 million people and 35% of India's irrigated land. In South America, in the dry Andes, glacial melt water contributes more to river flow than rainfall, even during the rainy season. Water is closely linked to food production. An average person drinks four liters of water a day, but the water required to produce our daily food is much more, around 2000 liters. Water tables are falling in countries that contain more than half of the world's population (06H1).

Go to this Chapter's Table of Contents ~ Go to top of Section [B] (Water-Soil-Salt Systems) ~ Go to top of Section [C] (Irrigation System Basics) ~ Go to top of Section [D] (Irrigation System Growth) ~ Go to top of Section [E] (Water Supplies and Urbanization-Limited Irrigation) ~ Go to top of Section [F] (Salinity and Waterlogging Limiting Irrigation) ~ Go to top of Section [G] (Irrigation System Abandonment) ~ Go to top of Section [H] (Surface Water Problems) ~ Go to top of Section [I] (Aquifer Degradation) ~ Go to top of Section [J] (Global Scale Water Scarcity) ~ Go to top of Section [K] (Global Water Inventory and Transfer Basics) ~Go to home page of this website ~ Go to List of References ~ Go to Introductory Chapter of this Sustainability Document ("Sustainability - Definitions, Context, Politics, History and its Role in the Evolution of Human Cultures")