The author's reputation for excellence in science and technical writing for youngsters should be expanded by the publication of this book. In addition to the well done engineering details involved in the construction of the biggest dams in this country and in Africa, Russia, India and Egypt, she has done a wonderful job of clarifying the social issues that arise whenever projects of this size are undertaken. For instance, there is an outline of the opposition to public ownership by the private power companies here, the pre-historic treasures threatened and then re-claimed when Egypt began its vitally necessary High Aswan Dam, and the moving story of ""Operation Noah"" attendant on the construction of the Kariba Dam in Africa. There are also discussions of the people displaced by trapping water over vast territory and insight offered on how the ""greatest public good"" can cause personal tragedy and the steps the government can take to alleviate it. The feast-or-famine cycles of agriculturally primitive or difficult regions and the prospect of controlling this through dam supplied power and irrigation is explained. This is one of those supplementary titles that fit easily into conservation and geography units while also satisfying the interests of tomorrow's engineers. Summary tables at the rear of the book compare sizes and capacities and there is a list of movies on dams available for classroom use.