A guide to help planners and engineers to the improvment of future water projects. The past century of global experience on water projects is presented as the basis for creating new approaches. First-hand analyses, including 35 case studies from 25 countries, portray the influence of politicians, biologists, engineers, computer models and physicians on the spectacular successes and failures of the builders of canals and dams. By drawing on this experience, the author outlines methods for assessing, predicting and preventing major water-associated diseases around large dams, canals and irrigation systems.