Only a little more than one-third of the world's 246 longest rivers remain free-flowing, drastically reducing the diverse benefits that healthy rivers provide to people and nature everywhere, according to a new study by World Wildlife Fund (WWF) and partners.
A team of researchers from WWF, McGill University, and other institutions studied about 7.5 million miles of rivers worldwide to determine whether they're well connected. They found that only 37 percent are free-flowing — meaning they're largely unaffected by human-made changes to its flow and connectivity. Damsbuilt in the wrong place and climate change are impacting river health worldwide, and the planet's remaining free-flowing rivers are largely restricted to remote regions of the Arctic, the Amazon Basin and the Congo Basin.
Vanishing free-flowing rivers
Long free-flowing rivers are vanishing. Around the world, rivers are becoming increasingly fragmented by dams and other development — such as roads or dikes — endangering freshwater ecosystems and the people and wildlife that rely on them. Free-flowing rivers transport water, nutrients and species that sustain biodiversity and benefit millions of people. To help countries and communities better protect their freshwater resources, WWF and partners came up with a technical definition of a free-flowing river and then created a first-of-its-kind, scientifically backed map — a comprehensive inventory of the world's last free-flowing rivers, rivers with good connectivity and impacted rivers.
1. Mura River — Slovenia
Called the "Amazon of Europe," the Mura River provides critical habitat for endangered and rare species such as otters, Danube salmon and black stork. After urging from WWF and others, in February 2019, the Slovenian government signed an agreement to stop all hydropower plant development that would devastate the Mura.
2. Usumacinta River — Mexico
In June 2018, guided by WWF and partners, Mexico established water reserves across nearly 300 river basins, guaranteeing water supplies for 45 million people for the next 50 years. Ninety-three percent of the water