Sustaining Water Resources

Abstract

Life depends on water and there are no substitutes. Fundamental to the functioning of the Earth’s system, water is a renewable natural resource that is available in finite amounts. Human appropriation of freshwater resources is mainly used for agriculture. To prevent loss of natural habitat and biodiversity, the growing demand for agricultural products will likely need to be met by enhancing crop yields in currently cultivated land rather than through farmland expansion. Because of local limitations in water availability, irrigation can be sustainably expanded only in part by the currently rain-fed farmland. Any further withdrawal from water bodies would deplete environmental flows or groundwater stocks. Local water deficits (i.e., gaps between availability and demand, including water for food) are often compensated for by food imports from water-rich regions and the associated transfers of “virtual water.” Thus, water is a strategic resource that has become strongly globalized and controlled by a few countries, while the rest of the world is in conditions of trade dependency. Water-saving strategies-based on food waste reduction, moderation of diets, use of more suitable crops, or increased water use efficiency-need to be adopted in order to meet human needs without compromising water sustainability.