Are we running out of water? Perhaps an overly dramatic question, but pressures on water supply are set to intensify and with them, geopolitical tensions are bound to rise. One source of pressure will be population growth. World population is projected to grow from 6 billion at present to 8 billion in 25 years' time.
Most of that growth will take place in countries which are already exposed to water-related difficulties, such as Ethiopia, whose population is expected to more than double from 62 million today to 136 million in 2025; that is about half of the population of the United States today.
The rapid urbanisation that has accompanied such fast population growth -- the urban population of developing countries will increase by a remarkable 2.5 billion over the next 25 years -- will pose its own serious problems for water supply. Many cities simply do not have the resources to accommodate the extra people. Infrastructures are already under strain and the financial burden of expanding services will be immense. Probably as much as $1 trillion of new investment would be needed to provide adequate sanitation for the urban population of poor countries.
And they will have to compete for this investment as richer countries upgrade or replace their existing systems. Pressure for investment in developed countries is bound to grow in line with public awareness, not just of environmental, but of sanitary issues too. It came as a shock to many, for example, to learn that the athletes who died after falling into a river in Tel Aviv during the 1997 Maccabiah Games did not drown, but were poisoned by the water.
One trend that is highly likely to aggravate water shortages is global warming, with a 1.5 to 3 degree rise in global temperatures expected over the next century, according to the Intergovernmental Panel on Climate Change (IPCC).
More water will clearly be consumed for irrigation and drinking, but there may be indirect effects too which would be more difficult to cope with. There could be increased evaporation and reduced groundwater recharge; a higher frequency of extreme weather conditions, such as storms (which can cause water treatment systems to overload); and a shift in climate zones and seasons which could have marked effects on water supply. Even in regions where the total annual precipitation did not change much, problems could arise if rainfall became concentrated in the winter or if it shifted away from agricultural zones.
A global issue
Climate change could probably have impacts beyond those areas vulnerable to catastrophic drought or floods. Countries such as the United Kingdom are beginning to study possible repercussions in a wide range of sectors, including the implications for water management. One finding is that even under the IPCC's conservative assumptions concerning temperature increases, water resources will become a major determinant of future land use. New housing projects may have to be abandoned because of lack of economical water supply, or because of flood risk.
So what can be done? There are large-scale technical solutions, which have helped countries like Egypt. Despite the droughts it was spared the tragic famines that struck Sub-Saharan Africa in the 1980s, even though it relies on the same hydrological basins for its water supply. And when it comes to deadly natural disasters like the flooding that killed thousands in China last year and made millions homeless, one strategy may be to build huge dams both as protection against climate fluctuations and to provide hydroelectric power.
However, interfering with nature can have unforeseen consequences. Critics of large technical solutions like to point to the Aral Sea drying up after the Soviet Union expanded cotton production by massive irrigation. For the time being at least, large-scale technical solutions are out of favour.
Smaller-scale technical solutions have also been proposed. Jordan is considering a scheme to take water from the Gulf of Aqaba on the Red Sea and transfer it by canal to the Dead Sea, using the difference in elevation to drive a hydropower plant. This plant would desalinate seawater and the brine rejected from the desalination plant would be discharged in the Dead Sea to stem the drop in sea level. Such projects, however ingenious, are unlikely to provide major sources of new water supply.
Attention is focusing on demand-side solutions to promote sustainable use, with the help of market-based pricing mechanisms. OECD countries are not running out of water, but supply problems are becoming more frequent. Global fresh water resources are likely to continue to suffer from waste and mismanagement due to excessively low prices, infrastructure deficiencies, and slow uptake of better technology. A key instrument for moving towards sustainable consumption would be to ensure that resources and ecosystems are given economic value and that external costs, such as those arising from pollution, are reflected in market prices.
Price reform is particularly attractive on economic grounds. For agriculture, which accounts for around 70% of global water consumption, compared with industry's 20% and the residen-tial commercial sector's 10%, some degree of intersectoral competition for scarce water resources could be entertained, as long as there was an end to subsidies and to public-led programmes to extend irrigation, except in special cases.
Tradeable rights are also a possible means of managing water resources, since it is argued that they would allow the price of water to reflect the value of its alternative uses, creating incentives to use it productively and cost-efficiently. For example, farmers selling at freely negotiated prices may have an incentive to improve their own water use efficiency in order to sell surpluses to cities, where the price is higher. However, such a system might be costly to set up and run. Laws would have to be changed, means of enforcing rights implemented, and perhaps new infrastructures built to carry water to potential customers. In any case, governments would still need to be involved in aspects such as quality standards or flood control.
Apart from the occasional restriction on watering the garden or washing the car, most people in OECD countries never give much thought to using water, and even less to how much it really costs or where it comes from. Action now to protect future supplies would ensure that this continues to be the case. Elsewhere, the situation is more worrying. Experience suggests that it will be extremely difficult to combine the political action, investment and forms of development required to ensure equitable access to adequate supplies of safe water for all.
Shiklomanov, Igor A., "World Water Resources: A New Appraisal and Assessment for the 21st Century", UNESCO, Paris, 1998.
"Water Consumption and Sustainable Water Resources Management" OECD, Environment Directorate, Paris, 1998.
©OECD Observer No 217/218, Summer 1999