Yes, the economic benefits of the Belo Monte dam outweigh the social and environmental costs. The Belo Monte dam provides significant economic benefit to the people that are impacted by the dam. Although there are environmental costs, they are minor in comparison. There will always be some kind of environmental costs to economic activity and human development.
Despite the controversial nature of the environmental assessments, the Belo Monte Dam is part of Brazil's push for hydroelectric power and more green energy. Green energy makes up 46 percent of Brazil's power consumption. If the dam is a success, more dams could follow among Brazil's many river systems to provide nearly limitless power for the developing country.