Integrated water management: emerging issues and challenges

Most of the projected global population increases will take place in Third World Countries that already suffer from water, food, and health problems. Increasingly, agricultural water management must be coordinated with, and integrated into, the overall water management of the region. Sustainability, public health, and environmental protection are key factors. More storage of water behind dam and especially in aquifers via artificial recharge is necessary to save water in times of water surplus for use in times of water shortage. Municipal wastewater can be an important water resource but its use must be carefully planned and regulated to prevent adverse health effects and, in the case of irrigation, undue contamination of groundwater. While almost an liquid fresh water of the planet occurs underground its long-term suitability as a source of water is threatened by nonpoint source pollution from agriculture and by aquifer depletion due to groundwater withdrawals in excess of groundwater recharge. Water short countries can save water by importing most of their food and electric power from other countries with more water, so that in essence they also get the water that was necessary to produce these commodities and, hence, is virtually embedded in the commodities. This 'virtual' water tends to be a lot cheaper for the receiving country than developing its own water resources. Local water can then be used for purposes with higher social or economic returns or saved for the future. (C) 2000 Elsevier Science B.V, All rights reserved.