From Florida to India, the growth of both human population and economies has created a hidden shortage in underground water supplies, or aquifers.
A global study by the World Water Commission, which is supported by the United Nations and World Bank, sternly warns of water crises in the next couple of decades. But it also lays out a variety of ways for communities, regions, and countries to take the pressure off aquifers or find other sources.
One expensive but readily available solution is to desalinize ocean or brackish water. Prices for such high-technology methods are dropping, and begin to look good when the long-range cost of overpumping aquifers and ground water - including all the environmental damage - is factored in.
But, for now, only wealthier areas can probably afford the investment of a desalinization plant. Instead of developing a whole new source of drinking water, people in many parts of the world are finding ways to put water back into their underground reservoirs safely.
The water commission cites a number of examples from India, such as an area-wide effort in western India to divert rain water into local wells, instead of allowing it to run off.
Users of the Hermosillo aquifer in Mexico have adopted stricter rules for water use, as well as less water-intensive agriculture, to reduce groundwater pumping by 50 percent over recent years. Such conservation through changes of habit and legal structure often don't come easily - whether in developing lands or in sprawling US cities.
And desalinization has its own problems.
Plans in Tampa, Florida, to have 10 percent of the water supply come from a new desalinization plant face persistent opposition. The most frequently heard objection is that the plant could raise the salinity of Tampa Bay, threatening sea life. Engineers, however, assure skeptics that the plant's discharge will be greatly diluted, with no danger to the ecology of the bay.
That project, which could be a landmark for desalinization in the United States, ought to go forward. Aquifers in Florida - and in numerous other parts of the globe - can't sustain unlimited pumping.
Whether it's desalinization, capturing rain water, water-saving farming methods, or water pricing structures that impel greater conservation, humanity should use every tool available to safeguard this most basic natural resource.
(c) Copyright 2000. The Christian Science Publishing Society