"World's Top Ten Rivers at Risk"

Executive Summary

What makes a river so restful to people is that it doesn’t have any doubt - it is sure to get where it is going, and it doesn’t want to go anywhere else.

Perhaps there was a time when that was true, but no longer. Even the greatest of the world’s rivers can no longer be assured of reaching the sea unhindered. These days the Rio Grande/Rio Bravo River, on the border of the U.S. and Mexico, often fails to reach the Gulf of Mexico, its strength sapped by dams and irrigation works diverting water to farmers’ fields and city water supplies. The Indus, the Nile, the Murray-Darling, the Colorado, these are but a few of the once mighty rivers that now struggle to touch the ocean.

In fact, water extraction is only one of the daunting challenges that a river faces as it makes its way to its terminus. Dams and channelization destroy habitats, cut rivers off from their floodplains, and alter the natural ebb and fl ow on which a river’s plants and animals depend. Invasive species crowd rivers’ banks, drive out their native fishes, and choke their courses.

Pollution fouls their waters, sometimes turning life-giving rivers into threats to human health. And climate change threatens to alter all the rules that rivers have lived by for thousands of years.

Why is this important? Because endangered rivers threaten the livelihoods of people. Rivers basins are the way nature gathers and delivers water for human use. These ecosystems provide electricity generation, transport, recreation and tourism, and valuable but often unaccounted fl ood and drought regulation, sediment and nutrient retention, and habitat for diverse fauna and flora. Freshwater biodiversity is an important source of food, income, and livelihood, particularly to rural communities in developing countries. Studies have estimated the economic value of river basins in the billions of dollars (Schuyt 2005)

WWF has selected the “top ten” major rivers that, in our view, either a) already suffer most grievously under the weight of these threats or b) are bracing for the heaviest impacts.

The primary objective of this report is to illustrate the most menacing threats to the world’s great river basins, in order to encourage dialogue, provoke debate, and urge governments and other stakeholders to take action before it is too late. To do this, WWF has selected the “top ten” major rivers that, in our view, either a) already suffer most grievously under the weight of these threats or b) are bracing for the heaviest impacts.

Thus, there are some rivers on the list that are so damaged that without serious restoration efforts they could be lost, and others that are relatively intact, but face massive degradation unless action is taken now to conserve them.

Surveying the results of eight international assessments, such as the Millennium Assessment ‘Wetlands and Water’ Synthesis Report that compiles the work of more than 2,000 authors and reviewers, WWF assessed the six most important threats based on their known impact on roughly 225 river basins. These are dams and infrastructure, excessive water extraction, climate change, invasive species, over-fi shing, and pollution.

We provide this overview of the most serious threats to river basins to highlight those globally important watersheds at greatest risk, and to stress the importance of integrated river basin management solutions. Focusing analysis on watersheds with high ecological importance and those affecting large human populations, with a view to continental representation, the ten most endangered rivers emerge as: the Salween, La Plata, Danube, Rio Grande, Ganges, Murray-Darling, Indus, Nile, Yangtze and Mekong.