“The key challenges of water management can only be understood within the context of water’s role in the world today” (WWDR 2, 2006: 1). Various factors play a part: the impact of extreme climates as witnessed in floods and drought conditions. many of the socio-economic systems in the world connecting at a rapidly growing rate. poverty,
warfare, diseases such as Acquired Immunodeficiency Syndrome (AIDS) afflicting many of the world’s populations. and the prevalence of increasingly crowded urban conditions. The world’s water managers have to monitor equitably and with more refined techniques, the increasingly scarce freshwater resource. At the same time, they have to face the complexities and pressures of the rapidly changing conditions and deterioration of available resources.
In November, 2002, the Covenant on Economic, Social and Cultural Rights (CESCR), created a milestone in the history of human rights by recognizing water as a fundamental human right. The one hundred and forty five countries which have approved the International CESCR will now be required to progressively ensure that there is access to safe and sufficient drinking water, without any form of discrimination among people (WWDR 1, 2003). The world’s socio-economic development including poverty alleviation, demographic and technological change, globalization, trade, warfare and security. as well as climate variability are each mutually interdependent with freshwater resources (UNESCO, 2006).
The natural cycle of water around the earth is the hydrological cycle. All water on earth is constantly recycled, repurified, and reused. The three main impacts that humans have on the hydrological cycle are: withdrawing freshwater for domestic, industrial or agricultural purposes, polluting the water while using it, and returning the used water into the hydrological cycle for purification through further stages till it is again available for use (Wright & Nebel, 2005