Viewed by some as symbols of progress and a necessary evil and by others as inherently flawed and destructive of ecosystems and societies, large dams remain the most contentious development issue on earth. Building on the work of the now defunct World Commission on Dams, Thayer Scudder, the world’s leading authority on large dams, wades into the debate with unprecedented authority. Armed with a vast array of cases studies and statistical data from Asia, including China and India, North America, Africa and Latin America, Scudder charts the ‘middle way’ forward by examining all aspects of the costs, benefits and risks to ecosystems, societies and economies of large dam development projects. Employing the World Commission on Dams’ Seven Strategic Priorities, Scudder analyses the structure of the decision making process for water resource and energy development and the planning, implementation and governance of assets when a large dam is selected as the best development option. He also assesses state-of-the-art procedures for addressing environmental, institutional, political and social issues, and tackles the highly contentious issue of dam-induced resettlement, illuminated by a statistical analysis of 50 cases.