Chapter 5 builds on the argument that the Brazilian military government largely ignored the social and environmental costs of its big dams because it was under pressure to build them quickly and cheaply and because it believed that its pharaonic environmentalism would satisfy its critics. It covers the twenty-year period from the late 1970s to the late 1990s, when reservoir floodwaters submerged cherished land and waterscapes that had been protected as national parks, engendered profound transformations to local fisheries, and set in motion ecological changes that led to devastating mosquito-related torments among communities living along the margins of reservoirs. To be sure, not all changes spelled disaster. Fisheries boomed in the decades following the formation of reservoirs, and malaria outbreaks were mild by historic standards. But in many places, disregard for the environment led to a series of local disasters that drew attention to the high environmental costs of big dams.

Chapter 2 covers the period in the late 1960s and early 1970s when the Brazilian military government planned and began building its big dams. It argues that political pressures encouraged the military regime to build dams with giant reservoirs and to do so quickly and without regard to their social and environmental footprints. The dictatorship looked to hydropower projects as a means of powering industrial and economic growth that would legitimize military rule, and it wasted no time in starting construction because it takes a long time to build big dams, often the better part of a decade, and sometimes longer. The 1973 oil crisis added urgency, raising the price of imported petroleum and pushing the government to invest in alternative sources of energy. The crisis encouraged the military regime to double down on the big dams already under construction and to plan a host of new ones. Political pressures also made their way into debates about specific dam sites. The most prominent case was the binational Itaipu Dam (on the Brazilian-Paraguayan Border), where the military government had to weigh geopolitical considerations alongside other criteria. The result of all these political pressures combined was a firm commitment to building large reservoirs in environmentally sensitive areas without public debate and without completing thorough environmental impact studies.