Mongabay joined an expedition of The Wilderness Project traveling the length of the Kafue River, part of TWP’s wider project to gather data in Africa’s major river basins.

On average, the total volume of the world's rivers was found to be 539 cubic miles from 1980 to 2009. For reference, that is about half the amount of water held in Lake Michigan, NASA reports.

The Yangtze River in Yunnan province, China. This river is one of many large rivers to have experienced a significant decline in water flow over the past 35 years, according to new research.

Dams disturb this by . In Africa, 26% of rivers have been fragmented or broken up – much lower than the . This means that African rivers are valuable hubs of connected river habitats.