A River Ran Through It

A River Ran Through It

Amazon environmentalists warn that hydroelectric dams could devastate the world's biggest watershed.

Photo Credit: Spectral Q/Chico/Paulo

The scores of rivers that feed the Amazon, like so many umbilical cords streaming nutrients downriver, sustain the animals, plants, and people who depend on them. Yet over the next two decades, a 300 percent increase in dam construction—in the Andean region alone—threatens to cut off an ancient life-support system.

In a recent study, biologist Clinton Jenkins of North Carolina State University and Matt Finer of the Center for International Environmental Law looked at 151 major hydroelectric dams planned for the six largest Andean tributaries of the Amazon River, spanning Bolivia, Colombia, Ecuador, and Peru, and found that a disorganized approach to dam building across the region was likely to cause significant ecological disruption.

“It’s surprising—few people are looking at the whole regional perspective, or any of the major threats in the Andean foothills: oil, road development, dams, and mining,” says Jenkins. “So we’ve been trying to systematically go through these sectors and look at the impacts on the whole region.”

Hydropower is, on the surface, preferable to burning fossil fuels. Look deeper, and the collateral damage is high: forests mowed down for roads and transmission lines, swaths of land flooded to create reservoirs, a river’s delicate ecosystem altered by the disruption of water flow, and the displacement of communities—all known side effects of dams.

The issues resonate for Jenkins, who grew up in the southern Appalachian foothills of eastern Tennessee, two miles downstream from a Tennessee Valley Authority dam. Built almost 80 years ago, the 32 dams built by the TVA displaced more than 14,000 families, disproportionately affected African Americans and the poor, and had a devastating effect on the biodiversity of the region.

But while the network of TVA dams was at least coordinated by the federal government, no such combined planning is behind the 151 large Andean dams proposed for the Caqueta, Madeira, Napo, Maranon, Putumayo, and Ucayali rivers. More than half the projects would, for the first time, interrupt the flow of water between the Andean mountains and the lowland Amazon, altering river habitats for thousands of miles downstream.

Rainfall and snowmelt from the Andes feed rivers that, in turn, flow into the Amazon, nourishing a huge flood-plain ecosystem teeming with life, including hundreds of migratory fish species. Some fish, like the dorado, travel 3,000 miles upstream from flood plains to the Andean foothills to spawn.

“There’s no rocket science here: If someone puts a dam in, it’s going to mess up migrations,” Jenkins says. “And with a lot of these proposed projects, no mitigation is planned [to offset the impacts]. And even if it is, does it work? Not a lot is known about these fish.”

What is known is that hundreds of communities rely on the rivers for their livelihoods and very survival.

“When I visit these communities, I see people of all generations, elders and children, living and working together. I see people fishing, people in paddle canoes or motor canoes, and I see a multitude of fish species including tambaqui and pirarucu,” says Leila Salazar-López, program director with Amazon Watch, an environmental organization waging a battle to stop construction of the Belo Monte dam in northeastern Brazil. “Without the river, indigenous and riverbank communities cannot continue their way of life—it’s not easy for them to pick up and move somewhere else.”

In place of dams, Amazon Watch is urging Brazil to concentrate on diversifying its energy economy. And Jenkins’s study urges governments to consider placing hydroelectric projects in smaller rivers outside of the Amazonian watershed, to minimize environmental impacts.

Mega-dams aren’t just an environmental concern; they’re also a social-justice issue, Jenkins notes. As in his native Tennessee, the Brazilians who stand to be displaced by dams aren’t the rich and powerful but the common folk who live in close connection to the land.

“There is this one region in Brazil where I work, where I really feel a connection,” he says. “It’s a region known as the ‘hillbilly’ region, and I grew up a hillbilly.”

What You Can Do

If You Have a Minute…
Use your Facebook page to educate friends and family about the global impact of dams. Share an online video by the organization International Rivers that depicts 200 years of dam proliferation in just 30 seconds:

If You Have an Hour…
Mark the International Day of Action for Rivers on March 14 by volunteering to give a presentation at your child’s or grandchild’s school on the importance of rivers. Download lesson plans for different age groups at

If You Have a Month…
Donate your time to an organization like Amazon Watch, which relies on volunteers for general support, research, data entry, web design and publishing, and language translation.
Email [email protected].

If You Have $100…
A donation to Amazon Watch can be used to help an indigenous leader opposed to Brazil’s Belo Monte dam project travel to the protest site. See

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