30 Things You Didn’t Know About Rivers

Rivers are the arteries of our planet. They contain only 0.003 percent of the water on Earth but sustain much of her life. Yet rivers are also under threat. The following list offers a brief introduction to their unique ecological, social and cultural value.

photo courtesy International RiversThe Nam Ou River in Laos which runs runs 448 km from Phongsaly Province to Luang Prabang Province.

1. Rivers are some of the most diverse ecosystems on the planet. Rivers and lakes sustain more fish species than the sea even though they contain 600 times less water.
2. Rivers feed us. Freshwater fisheries currently sustain up to 550 million people on a fish-based diet.
3. Rivers are the cradles of our civilizations. Our most ancient cultures sprang up along rivers such as the Tigris and Euphrates, the Nile, the Indus, and the Yellow.
4. Dams have fragmented two thirds of the world’s great rivers. They store about 7,000 cubic kilometers or one sixth of the water flowing in rivers.
5. Rivers shape our planet and have created some of its most beautiful landscapes. Think of the Grand Canyon, the Iguaçu and the Victoria Falls!
6. We cry to Ol’ Man River, dance By the Rivers of Babylon, and waltz along the Blue Danube. Rivers have inspired great music around the world.
7. With a length of 6,853 kilometers, the Nile is the world’s longest river. With a mere 27 meters, the Reprua River in the Caucasus may be the shortest.
8. An estimated 10,000-20,000 freshwater species have been lost or are at risk. 37 percent of the world’s freshwater fish species – including 24 of 26 sturgeon species – are threatened by extinction.
9. By depositing nutritious silt on floodplains and deltas, rivers have created our most fertile agricultural lands, from the Mekong Delta to California’s Central Valley.
10. Rivers sustain fish populations offshore. Because of the nutrients they carry to the sea, 80 percent of the world’s fish catch comes from continental shelves.
11. Rivers unite us. Some 276 rivers flow across more than one country, and their basins cover almost half the Earth’s land surface.
12. At most, 64 of our 177 longest rivers remain free-flowing, and many of them are threatened by fragmentation.
13. Rivers have brought us great movies. Films like African Queen, Deliverance and Aguirre, the Wrath of God have become classics.
14. Rivers generate power. Hydropower accounts for some 16 percent of the world’s electricity – often at great cost to river ecosystems and communities.
15. In the US, one sixth of all inland freight is transported on rivers and canals. Navigation is the most energy-efficient mode of transport, but has turned healthy rivers into highways.
16. Every year, rivers take 200 million tons of carbon out of the ground and the air and transport it to the sea. They also power the role of oceans in taking carbon out of the atmosphere.
17. Because of over-exploitation, once mighty rivers like the Colorado, Indus, Nile, Rio Grande and Yellow are struggling to reach the sea.
18. Rivers inspire us and give religious meaning. In India and other countries, many rivers are revered as gods.
19. With a depth of more than 220 meters – four Niagara Falls stacked on top of each other – the Congo is the world’s deepest river.
20. Rivers create identity. At least 17 countries – from India to Nigeria – are named after rivers. Another 17 – from Saudi Arabia to the Bahamas – have no rivers at all!
21. Over-exploitation of rivers through dam building and pollution threaten the water security of almost 5 billion people around the world.
22. Have you read Huckleberry Finn, Heart of Darkness, and A River Runs Through It? Rivers have inspired great literature in many countries.
23. Rivers have created some of the world’s most-treasured natural heritage. More than 30 riverscapes – from the Pantanal to the Okavango Delta – have been recognized as World Heritage Sites.
24. Freshwater species have lost 76 percent of their populations since 1970 – twice the loss which marine and terrestrial ecosystems have suffered.
25. The Amazon discharges 84 Olympic-size pools into the sea every second – more than all European and North American rivers combined. It is the biggest river on the planet.
26. Healthy rivers and their floodplains absorb rainfall and release it over time. They protect us against the floods and droughts which are getting ever more severe under climate change.
27. Rivers provide important services such as water supply and regulation for free. They have been estimated to be 10-15 times more valuable per hectare than land and sea-based ecosystems.
28. Another 3,700 hydropower dams are currently under construction or in the pipeline. Many of them are located in river basins with high ecological values such as the Amazon and Mekong.
29. Rivers are the arteries of our planet. By connecting lands, lakes and the sea, they enable the circulation of nutrients, sediments, and living beings.
30. Rivers contain only 0.003 percent of the water on Earth – one out of every 33,000 water molecules – but sustain much of her life. They deserve our protection!