Shortages of water could become a major obstacle to public health and development. Currently, the United Nations Children's Fund (UNICEF) and the World Health Organization (WHO) estimate that 1.1 billion people lack access to a water supply and 2.6 billion people lack adequate sanitation. The global health burden associated with these conditions is staggering, with an estimated 1.6 million deaths every year from diseases associated with lack of access to safe drinking water, inadequate sanitation and poor hygiene. In this paper we review the impact of water shortages on health and human development.