There is an estimated billion km3 of water in the world but only approximately three percent (39 million km³) of it is available as fresh water. Moreover, most of this fresh water is found as ice in the arctic regions, deep groundwater or atmospheric water. Since water is the source of life and essential for all life on the planet, the use of this resource is a highly important issue. 'Water management' is the general term used to describe all the activities that manage the optimum use of the world’s water resources