Fact Sheet

FRESHWATER RESOURCES

• Although water is the most widely occurring substance on earth, only 2.53 per cent is freshwater while the remainder is salt water.

• About two thirds of this freshwater is locked up in glaciers and permanent snow cover.

• Water resources are renewable (with the exception of groundwater) and have huge differences in availability in different parts of the world and wide variations in seasonal and annual precipitation in many places.

• Precipitation is the main source of water for all human use and for ecosystems. This precipitation is taken up by plants and soils, evaporates into the atmosphere via evapotransportation, and runs off to the sea via rivers, and to lakes and wetlands. The water from evapotransportation supports forests, rainfed cultivated and grazing lands, and ecosystems. We withdraw 8 per cent of the total annual renewable freshwater, and appropriate 26 per cent of annual evapotransportation and 54 per cent of accessible runoff.

• Freshwater resources are further reduced by pollution. Some 2 million tons of waste per day are disposed of in receiving waters, including industrial waste and chemicals, human waste and agricultural waste (fertilizers, pesticides and pesticide residues), thereby reducing freshwater resources.

• As ever, the poor are the worst affected, with 50 per cent of the population of developing countries exposed to polluted water sources.

• By the middle of this century, at worst, 7 billion people in sixty countries will be water-scarce, at best 2 billion people in forty-eight countries.

WATER AND HEALTH

• Water-related diseases are among the most common causes of illness and death, affecting mainly the poor in developing countries. Water-borne diseases causing gastro-intestinal illness, including diarrhea, are caused by drinking contaminated water; vector-borne diseases, such as malaria and schistosomiasis, are passed on by the insects and snails that breed in aquatic ecosystems; water-washed diseases (scabies, trachoma) are caused by bacteria or parasites that take hold when there is insufficient water for basic hygiene.

• In 2000, the estimated mortality rate due to water/sanitation hygiene-associated diarrheas and some other water/sanitation-associated diseases (schistosomiasis, trachoma, intestinal helminth infections) was 2,213,000. There were an estimated 1 million deaths due to malaria.

• Worldwide, over 2 billion people were infected with schistosomes and soil-transmitted helminths, 300 million of whom suffered serious illness.

• However, at a domestic level, access to safe drinking water, sanitation that stops contaminants from reaching sources of drinking water, plus hand-washing and careful food handling are, collectively, key tools in fighting gastro-intestinal illness.

• Presently, 1.1 billion people lack access to improved water supply and 2.4 billion to improved sanitation. In the vicious poverty/ill-health cycle, inadequate water supply and sanitation are both underlying causes and outcomes. Invariably, those who lack adequate and affordable water supplies are the poorest in society.

• If improved water supply and basic sanitation were extended to the present-day `unserved', it is estimated that the burden of infections would be reduced by about 17 per cent annually.

• If a well-regulated water supply and full sanitation were achieved, this would reduce the burden by about 70 per cent annually.

Analyses of the cost effectiveness of water interventions suggest further that:

1) Disinfection of water with chlorine tablets at the point of use and safe storage, combined with limited hygiene education is the biggest health benefit at the lowest incremental cost; and

2) Disinfection of water at the point of use is consistently the most cost effective intervention. Improved hand-washing is also highly effective.

• The draining of wetlands for agriculture (50 per cent lost in the last century) and the appropriation of evapotransportation (by land clearance) lead to further perturbation of natural systems and will cause profound impacts on the future availability of water.

WATER FOR FOOD

• Providing the 2,800 calories per person per day needed for adequate nourishment requires an average of 1,000 cubic metres (m³) of water.

• Some 15 per cent of agricultural water is used in irrigation, totaling about 2,000-2,500 cubic kilometers (km³) per year.

• In 1998, irrigated land produced two fifths of all crops and three fifths of all cereals in developing countries. Cereals are the most important crop, providing 56 per cent of calories consumed. Oil crops are the next most important.

• Presently, irrigation accounts for 70 per cent of all water withdrawals. Amounts will increase by 14 per cent in the next thirty years as the area of irrigated land expands by a further 20 per cent.

• By 2030, 60 per cent of all land with irrigation potential will be in use. Of the ninety-three developing countries surveyed by the Food and Agricultural Organization (FAO), ten are already using 40 per cent of their renewable freshwater for irrigation.

• An important source of irrigation water is wastewater, with about 10 per cent of the total irrigated land in developing counties using this resource. It provides direct benefits to farmers who are short of water; it can improve soil fertility and reduce contamination of what would otherwise be downstream receiving waters.

• For irrigation use, wastewater should receive treatment, but in lower-income countries, raw sewage is often used directly, for which the associated risks include the exposure of irrigation workers and food consumers to bacterial, amoebic, viral and nematode parasites, as well as organic, chemical and heavy metal contaminants.

• Despite the foregoing, 777 million people in developing countries are under-nourished and the target of halving this will not be met before 2030. This situation has arisen more from national conflict than from water insecurity. In the last decades, agricultural production has grown faster than the worlds' population and there is no evidence that this should change. Overall, the message from agriculture is cautiously optimistic.

WATER AND INDUSTRY

• Global annual water use by industry is expected to rise from an estimated 725 km³ in 1995, to about 1,170 km³ by 2025, by which time, industrial water usage will represent 24 per cent of all water abstractions.

• Much of the increase will be in developing countries now experiencing rapid industrial development.

WATER, NATURAL DISASTERS & COOPERATION

• Between 1991 and 2000, the number of people affected by natural disasters rose from 147 million per year to 211 million per year. In the same period, more than 665,000 people died in 2,557 natural disasters, of which 90 per cent were water-related. Of these water-related disasters, floods represented about 50 per cent, water-borne and vector-borne diseases about 28 per cent, and droughts 11 per cent. Floods caused 15 per cent of deaths and droughts, 42 per cent of all deaths from all natural disasters.

• There are presently 261 international river basins, and 145 nations have territories in shared basins. Rarely do the boundaries of the watersheds coincide with existing administrative boundaries.

• Despite the potential problem, experience suggests that cooperation, rather than conflict, is likely in shared basins. Figure 6, based on an analysis over fifty years, shows that 1,200 cooperative interactions have occurred in shared basins, versus 500 conflictual ones, and there were no formal wars.