The São Francisco River runs along part of the border between the Brazilian states of Bahia (below) and Pernambuco (above). The 3,160 kilometre-long river is the longest river located entirely within Brazil.
The segment of the river on the right side of the image appears much wider than that on the left side due to water held behind several dams. Four hydroelectric plants and dams are located along the river’s course: the Paulo Afonso Dam, Três Marias, Sobradinho and Luiz Gonzaga (Itaparica)
In addition to being used for hydroelectric power, in 2005, the Brazilian government proposed a controversial irrigation project called the “Transposition of the São Francisco” that would bring water from the river to semiarid areas of four Brazilian states.
Environmentalists argue that the project will do more harm than good, benefitting only large landowners and a very small population, while bringing considerable ecological impact. The government, on the other hand, insists that the project will give the people in the four states a much-needed water supply.