The colonization of Rond nia started in the late 1960s, a process made easier with the construction of BR-364. Machadinho D’Oeste received the first settlers in 1984, the agrarian reform projects in Rond nia favored small farmers as opposed to large landowners. Some of these subjects who migrated to Machadinho D’Oeste did because the displacement caused by Itaipu Hydroelectric Dam. With the announcement of the construction of the Tabajara Hydroelectric Dan, discussions are emerging, such as the role of Environmental Impact Studies - and their necessary assessment of cumulative impacts -, in theory an instrument to analyze the impacts generated by the works, including popular participation through the hearings public; that in practice it has been shown to be a mechanism that legitimizes the plunder of natural resources and that endorses the omissions brought in it. These elements indicate the need to deepen the discussions on yet another project that is advancing in the Amazon, the Tabajara Hydroelectric Dam.