That water is a finite resource to be conserved and protected is not yet universally perceived. Generally, fresh water is respected as a giver-of-life only in regions of chronic shortage. Of the world's water, between two and five percent is fresh; but 87 percent of this is frozen in the polar regions. Most of the rest is underground, in the atmosphere and in living organisms. No more than one percent is surface freshwater in lakes and rivers.
Only half of the world's groundwater is within a half-mile of the surface and therefore within the reach of man. Reservoirs of such fossil water are a nonrenewable resource, deposited thousands of years ago. They are not being replenished and will be exhausted sooner rather than later. Groundwater often is found where surface water is insufficient or negligible, as in the Sahara and the southwestern USA. Although fresh reserves of underground water should be reserved for drinking and household needs, it is used by industry even when surface water is available.
In the quest for greater food production, the management of water resources is central. Agricultural use of water has always been large relative to industrial and domestic uses, but the absolute amount of water used by agriculture has increased four-fold during the period from 1900 to 1980 and is projected to rise to five-fold by the year 2000. In 1990, agricultural use of water was almost double that of all other uses. Irrigation uses of groundwater often compete with domestic uses. In addition to depleting freshwater reserves, the underground or surface freshwater resource is also vulnerable to pollution by agricultural runoff and seepage of chemicals applied to the land.
The inadequate management of water resources is compounded because whilst researchers know that resources have been degraded and are further threatened, they cannot measure the severity of either since the development of adequate information networks has been hindered. Several studies have pointed to the deterioration of national hydrological instrument networks since governments have decreased their funding. Whilst many governments have invested heavily in satellites, it is argued that they do not compensate for insufficient ground-based stations.
Freshwater problems are acute and worsening. Most arise from the poor management of water resources, lack of financial resources required for sustainable development and efficient utilization of resources, absence of effective regional and basin development plans and shared management, and under-estimation of the groundwater potential to supplement irrigation and drinking water supplies.
Rapid population growth, expanding economic activity and poor irrigation practices endanger water resources which are often already overloaded with dangerous chemicals and raw sewage. With demand exceeding supply in many countries, uncertainty surrounds the damaging long-term effects of these conditions. Across Europe, 35% of water use represents depletion; the remainder is returned to river, lakes or coastal waters as waste water of varying quality. In Pakistan, the freshwater problems represent the major constraint on economic development. In the next decade, this situation will develop in other countries.