The main purpose of the book is to create an awareness of the important couplings between water and energy. It is an attempt to show how energy is used – and misused – in all the various water cycle operations as well as to demonstrate how water is used – and misused – in energy production and generation. The book does not aim to show ‘how to design’ or to solve some of the intricate conflicts. Instead it tries to systematically list ideas, possibilities and some results.