Sustainability, sustainable management or integrated management of natural resources (also known as common-pool resources) have become buzz words in the growing literature around environmental management. Researchers now focus on complex and dynamic linkages between ecological systems, social, and economic aspects of society to achieve sustainability. A lot of researchers focus on case studies to show the existence of various management systems of natural resources while others focus on theoretical frameworks of management systems that support sustainable use of such resources. The concept of “co-management” has emerged from both types of research. This book focuses on co-management of one of such common-pool resources “water”. An attempt has been made to combine research with action. The idea is that success and failures described in case studies with lessons learnt can be useful stepping stones for both policy makers and managers to apply to their own situation. This chapter briefly touches on some definitions, principles and complexities involved in co-management (with reference to adaptive co-management) followed by a road-map of the book.