Water is vital for all living things. Rivers, lakes and wetlands support a variety of wildlife and habitats. However, the environmental need for water must be balanced against human water use. In most areas of England and Wales , the balance between users and the environment is sustainable but, in some locations, water-based ecosystems are under threat. European Directives aimed at protecting the water environment will have impacts on how human water needs are met. This POSTnote examines the potential risks and opportunities for the provision of public water supply as the Directives are implemented in England and Wales. It precedes the House of Lords Science and Technology Select Committee report on Water Management.