Catalog

	Table of Contents
p. 1 of 19 BACK | NEXT Emerging Global Water Issues Water Quality, Pollution, and the Environment A Double-Edged Sword: Flood and Droughts Geographical Variability in Water Resources Shared Waters Heightened Awareness of Water Issues Elements of a Water Strategy Imperatives for Wise Water Management ADB's Evolving Role in the Changing Context

Water in the 21st Century

---

Emerging Global Water Issues

The Looming Water Crisis

Earth is the blue planet with water one of the most plentiful natural substances in its environment. There is more than 1.4 billion cubic kilometers (km³) of the stuff-enough to give every man, woman, and child more than 230 million cubic meters (m³) each if we were to divide it evenly.

However, more than 98 percent of the world's water is salt water and we depend for our basic vital needs on freshwater. Most freshwater is locked in the polar ice caps. Less than 1 percent of the earth's freshwater is accessible in lakes, rivers, and groundwater aquifers. That vital 1 percent of available freshwater is constantly in motion, either flowing in rivers, evaporating and moving around the globe as water vapor, falling from the sky as rain or snow, or filtering slowly through the earth to emerge somewhere else. It is a renewable resource on which we all completely depend. It is the genesis and continuing source of all life on earth.

The most accessible water is that which flows in river channels or is stored in freshwater lakes and reservoirs. The major portion of the water diverted for human needs is taken from this renewable, readily accessible part of the world's freshwater resources. Although the total volume of water conveyed annually by the world's rivers is about 43,000 km³ (see figure), most of this occurs as floods-the low river flows (base flows) make up only about 19,000 km³.¹ Of this, about 12,500 km³ can be accessed, and present levels of withdrawal account for about 4,000 km³. Withdrawals are anticipated to reach 5,500 km³ per year by 2025.

The demand for freshwater increased sixfold between 1900 and 1995, twice the rate of population growth.² The 1997 United Nations (UN) Comprehensive Assessment of Freshwater Resources of the World concluded that one third of the world's population today already live in countries experiencing medium to high water stress. High water stress and unsustainable rates of withdrawal are already being experienced in Central and South Asia, where annual water withdrawals compared with available water resources are 50 percent or more. The northern People's Republic of China (PRC) and Mongolia have medium stress conditions with 25 percent water use. Although water stress (see box on page 8) computes at less than 10 percent in Southeast Asia (including southern PRC) and the Pacific and is therefore considered to be low, this measure is highly distorted by seasonally high river flows. In the dry season, water scarcity occurs throughout Asia and the Pacific, and increased rainfall variability as a result of global climate change will worsen this problem. Water scarcity will affect food security throughout Asia and the Pacific.

The global population will expand from today's 6 billion people to almost 8 billion in 2025. By then, more than 80 percent of the world's population will be living in developing countries. The World Meteorological Organization estimates, assuming the renewable water resources will remain unchanged, that the number of countries facing water stress will increase from 29 today to 34 in 2025. How these countries manage their water resources, and whether they can produce sufficient food for their growing populations while catering to their water needs and preserving natural environments, have important implications-and imperatives-for the Asian Development Bank (ADB) and its developing member countries (DMCs). ADB has been extensively involved in planning, formulating, and financing water resource projects in its DMCs, and has accumulated valuable experience that must be used to respond proactively to the challenge. The poverty reduction strategy adopted in 1999 enjoins ADB, at the policy level, to continue to support governments in developing, in a participatory manner, master plans for effective management of critical natural resources, including water.

Competition for water is increasing among different water uses, including water for ecological needs. In many DMCs, irregular and inequitably distributed supplies of piped water have a detrimental effect on the social and economic well-being of most of their citizens. Ironically, consumers in almost all DMCs are charged less for their water than it costs to provide. Hence, utilities are reluctant to connect new customers because water prices are too low to allow them to recoup their investment. For the poor, access to even a rudimentary level of municipal water supply is frequently denied, and they may be constrained to use untreated water from highly unreliable sources. Waterborne diseases are causing immense suffering and loss of productivity, with the poor suffering disproportionately. Large cities in Asia are not equipped to offer their burgeoning populations the water supply and sanitation services they require.

Nearly 70 percent of global freshwater withdrawals are directed toward agriculture, mainly for irrigation. By some estimates (UN 1997), annual irrigation water use will have to increase about 30 percent above present use for annual crop production to double and meet global food requirements by 2025. Although irrigation will remain the dominant water use in developing countries, an increase of 30 percent in irrigation withdrawals may not be possible if other essential human needs are to be met. Making irrigation more efficient will be necessary and unavoidable. The industry sector, which accounts for about 22 percent of current freshwater withdrawals globally, is likely to require an increasing share in all regions of the world in both absolute and relative terms. In developing countries, where 56 percent of the population will be living in urban areas by 2025, the share of water going toward domestic uses will also need to grow substantially.

Back Water in the 21st Century	Next Water Quality, Pollution, and the Environment