More than one billion people around the world lack access to clean drinking water; some 2.5 billion do not have adequate sanitation services. Preventable water-related diseases kill an estimated 10,000 to 20,000 children every day, and latest evidence suggests that we are falling behind in efforts to solve these problems. Massive cholera outbreaks appeared in the mid-1990s in Latin America, Africa and Asia. Millions of people in Bangladesh and India drink water contaminated with arsenic. And the surging populations throughout the developing world are intensifying the pressures on limited water supplies.
The effects of our water policies extend beyond jeopardising human health. Tens of millions of people have been forced to move from their homes-often with little warning or compensation-to make way for the reservoirs behind dams. More than 20 percent of all freshwater fish species are now threatened or endangered because dams and water withdrawals have destroyed the free-flowing river ecosystems where they thrive. Certain irrigation practices degrade soil quality and reduce agricultural productivity, heralding a premature end to the green revolution. Groundwater aquifers are being pumped down faster than they are naturally replenished in parts of India, China, the US and elsewhere. And disputes over shared water resources have led to violence and continue to raise local, national and even international tensions.
At the outset of the new millennium, however, the way resource planners think about water is beginning to change. The focus is slowly shifting back to the provision of basic human and environmental needs as the top priority-ensuring some for all, instead of more for some. This means using existing infrastructure in smarter ways rather than building new facilities, which is increasingly considered the option of last, not first, resort. The challenges we face are to use the water we have more efficiently, to rethink our priorities for water use and to identify alternative supplies of this precious resource.
This shift in philosophy has not been universally accepted, and it comes with strong opposition from some established water organisations. Nevertheless, it may be the only way to successfully address the pressing problems of providing everyone with clean water to drink, adequate water to grow food and a life free from preventable water-related illness.
Damage from dams
As environmental awareness has heightened globally, the desire to protect-and even restore-some of the river systems destroyed by dams and embankments has grown. In many developing countries, grassroots opposition to the environmental and social costs of big water projects is becoming more and more effective. Villagers and community activists in India have encouraged a public debate over big dams. In China, where open disagreement with government policies is strongly discouraged, protest against the monumental Three Gorges Project has been unusually vocal and persistent. Until very recently, international financial organisations such as the World Bank, export-import banks and multilateral aid agencies subsidised or paid in full for dams or other water-related civil engineering projects-which often have price tags in the tens of billions of dollars. These organisations are slowly beginning to reduce or eliminate such subsidies, putting more of the financial burden on already strained national economies. Having seen so much ineffective development in the past-and having borne the associated costs (both monetary and otherwise) of that development-many governments are unwilling to pay for new structures to solve water shortages and other problems.
A handful of countries are even taking steps to remove some of the most egregious and damaging dams. Fortunately-and unexpectedly-the demand for water is not rising as rapidly as some predicted. As a result, the pressure to build new water infrastructures has diminished over the past two decades. Although population, industrial output and economic productivity have continued to soar in developed nations, the rate at which people withdraw water from aquifers, rivers and lakes has slowed. And in a few parts of the world, demand has actually fallen
Demand's down-for how long?
What explains this remarkable turn of events? Two factors: people have figured out how to use water more efficiently, and communities are rethinking their priorities for water use. In 1965, for instance, Japan used approximately 13 million gallons of water to produce $1 million of commercial output, by 1989 this had dropped to 3.5 million gallons (even accounting for inflation)-almost a quadrupling of water productivity. In the US, water withdrawals have fallen by more than 20 percent from their peak in 1980.
As the world's population continues to grow, dams, aqueducts and other kinds of infrastructure will still have to be built, particularly in developing countries where basic human needs have not been met. But such projects must be built to higher standards and with more accountability to local people and their environment than in the past. And even in regions where new projects seem warranted, we must find ways to meet demands with fewer resources, minimum ecological disruption and less money.
The fastest and cheapest solution is to expand the productive and efficient use of water. In many countries, 30 percent or more of the domestic water supply never reaches its intended destinations, disappearing from leaky pipes, faulty equipment or poorly maintained distribution systems. The quantity of water that Mexico City's supply system loses is enough to meet the needs of a city the size of Rome, according to recent estimates. Even in more modern systems, losses of 10 to 20 percent are common.
When water does reach consumers, it is often used wastefully. In homes, most water is literally flushed away. Before 1990, most toilets in the US drew about six gallons of water for each flush. In 1992 the US Congress passed a national standard mandating that all new residential toilets be low-flow models that require only 1.6 gallons per flush-a 70 percent improvement with a single change in technology. Even in the developing world technologies such as more efficient toilets have a role to play. Because of the difficulty of finding new water resources for Mexico City, city officials launched a water conservation programme that involved replacing 350,000 old toilets. The replacement have already saved enough water to supply an additional 250,000 residents. And numerous other options for both industrial and non-industrial nations are available as well, including better leak detection, less wasteful washing machines, drip irrigation and water-conserving plants in outdoor landscaping. The largest single consumer of water is agriculture-and this use is largely inefficient. Water is lost as it is distributed to farmers and applied to crops. Consequently, as much as half of all water diverted for agriculture never yields any food. Thus, even modest improvements in agricultural efficiency could free up huge quantities of water. We can conserve water not only by altering how we choose to grow our food, but also by changing what we choose to eat.
New approaches to meet water needs will not be easy to implement: economic and institutional structures still encourage the wasting of water and the destruction of ecosystems. Among the barriers to better water planning and use are inappropriately low water prices, inadequate information on new efficiency technologies, inequitable water allocations, and government subsidies for growing water-intensive crops in arid regions or building dams.
Part of the difficulty, however; also lies in the prevalence of old ideas among water planners. Addressing the world's basic water problems requires fundamental changes in how we think about water; and such changes are coming about slowly. Rather than trying endlessly to find enough water to meet hazy projections of future desires, it is time to find a way to meet our present and future needs with the water that is already available, while preserving the ecological cycles that are so integral to human well-being.