In the fight against the Hidrovía project, Rivas and Diaz led a coalition of 300 groups of indigenous people, local communities and environmentalists from each of the five interested nations to develop a “floating seminar.” The educational campaign traveled 1,200 kilometers in three traditional riverboats, along the Paraguay River to alert local communities to the implications of the Hidrovia project. They successfully persuaded the Hidrovía’s sponsors to recognize the project’s negative social and environmental impacts, and proposed sustainable alternatives that would not require large-scale interventions on the rivers.