Logo IMG


Where the Xingu Bends and Will Soon Break

A hotly contested megadam threatens one of the world’s greatest assemblages of rapids-adapted fishes and homogenizes an incubator for evolutionary diversity.

Mark Sabaj Pérez

2015-11SabajPerezF1.jpgWith its globally unique geomorphology, hydrology, and aquatic biota, Brazil’s Xingu River offers a seemingly foolproof argument for its preservation. Yet the will to harness the Xingu for hydroelectricity has prevailed over decades of heroic efforts to sustain its natural course. After four years of nearly round-the-clock construction, the Belo Monte megadam is set to become operational in the fall of 2015. At peak capacity, Belo Monte is expected to generate 11,233 megawatts, exceeded only by the Three Gorges Dam (22,500 megawatts) in China and the binational Itaipu Dam (14,000 megawatts) on the Paraná River between Brazil and Paraguay.

Belo Monte will directly affect at least 170 river kilometers of the Xingu channel by flooding nearly half that stretch and dewatering the rest. The response of rapids-loving fishes to the inundated portion will be as clear as the Xingu itself—they will decline in number if not disappear. Less clear is the fate of fishes inhabiting the Xingu below the reservoir and above Belo Monte, where the diverted water rejoins the main channel. That will depend largely on how much water is allowed to spill freely below the reservoir.

Tracking the environmental impacts of Belo Monte will require comprehensive data on local biodiversity and ecology prior to the dam’s completion. In the ongoing iXingu Project, American scientists such as myself have joined Brazilian efforts to establish that critical baseline.

“God only makes a place like Belo Monte once in a while. This place was made for a dam.” This remark by a barrageiro (dam builder), quoted by ecologist Philip Fearnside, echoes a distinct subculture in Brazilian society with grand ambitions for colossal dam projects, ostensibly to supply clean and renewable energy. At the close of 1984, the barrageiros could boast two important megadams: Itaipu, listed among the seven greatest civil engineering feats of the 20th century, and Tucuruí on the Tocantins River, the world’s fifth largest dam until Belo Monte is operational. In 1987, an epic national plan for electricity betrayed the barrageiros’ bravado. Produced by the Brazilian utility company Eletrobrás, the so-called “2010 Plan” listed 297 new dams to be constructed throughout Brazil in the coming decades. Included were five dams on the Xingu among a total of 79 dams sited throughout the Amazon Basin. Those dams would flood an estimated 10 million hectares or 3 percent of the originally forested Amazon Basin.

The barrageiro’s plans for the Xingu immediately ignited intense controversy, given the scope and magnitude of potential biological and cultural impacts. And so it began, the struggle over Belo Monte. Alongside the barrageiros, politicians publicly promoted Belo Monte as essential to energy security and economic progress. Aligned against Belo Monte were a broad coalition of indigenous tribes, grassroots organizations, academics, nongovernmental organizations, and government agencies responsible for protecting natural resources and the rights of dam-affected peoples. Early protests culminated in the First Meeting of Indigenous Peoples in Altamira in 1989 during which Tuíra, a member of the Kayapó tribe, laid her machete against the face of a chief engineer, becoming a global icon for hostility toward the Xingu dams.

The movement against the dams received a counterwarning in 2001 when the federal government began rationing electricity in response to a blackout crisis due in part to water shortages for hydroelectricity. That crisis revived plans for Belo Monte as a strategic interest for hydropower expansion. Since then, despite sustained and vocal opposition, Belo Monte has progressed through licensing to construction.

2015-11SabajPerez_Inset_wText.jpgClick to Enlarge Image

Over the course of one pilot and three full expeditions, the iXingu Project has gathered a wealth of specimens and empirical data that, when combined with Brazilian-led studies, afford a valuable snapshot of the fauna and ecology of the middle and lower Xingu. Such knowledge is essential for assessing the eventual impacts of Belo Monte and will inform future efforts to conserve what remains of the Xingu.

comments powered by Disqus


Subscribe to American Scientist