Fresh Water

Freshwater resources are vital for meeting basic human needs and inadequate protection of the quality and the supply of freshwater can set important limits to sustainable development. Many health hazards in developing countries and transition-economy countries are related to poor water quality and limited water quantity. Many of these countries use more than their annual freshwater renewal rate by satisfying demands from non-renewable resources. This water shortage is expected to worsen as a result of several factors including population growth compounded by continued rural-urban migration, pollution of surface water sources, and an increase in the standard of living resulting in growing demand.

Traditionally, governments respond to extra demand by increasing the water supply for urban dwellers; a practice which is becoming more and more difficult as sources of good quality water become geographically more distant, making it more expensive to explore and develop. Abstraction of ground water will not make up the difference either as over-pumping has lead to salt-water intrusion and a lowering of water tables in many parts of the world. Planners must therefore make wider use of both conventional and non-conventional technologies for maximizing the use and augmenting freshwater resources.Lakes and reservoirs have special characteristics due to their nature and dynamics that make them to be vulnerable to pollution. Over time the loading of contaminants has resulted in the degradation of the water quality and loss of biodiversity due to various causes including eutrophication. Eutrophication of lakes and reservoirs is becoming more serious due to the continuous loading of organic matter, phosphorous and nitrogen into these water bodies. The nutrients are originated mainly from agricultural run-off as well as from industrial and urban discharges. Fertilizers from agriculture as well as domestic and industrial sewage are constantly entering these water