Water is life: adequate supply of water is central to life and
civilization. The five basic human needs namely air, water, food, light,
 and heat. Water is common factor to other four. It is therefore not an
understatement to say water is life, because it forms an appreciable
proportion of all living things including man. In fact, water is very
critical to human life. Water constitutes about 80% of animal cells. The
 human body by weight consists of about 70% water and several body
functions depend on water (Human development report 2006