Rivers are the arteries of the planet, providing most of the fresh surface water used by populations. 263 international river basins are estimated to cover about 50% of the Earth's surface, but by volume they carry about 2,120 km3, or about 6/1,000 of 1% of the total water (Table 1). About 40% of the world's population lives in river basins comprising two or more countries. According to the United Nations, 145 countries have territory within international basins. Although most basins are shared between just two countries, there are many basins where this number is much higher. There are 13 basins in the world shared between 5 and 8 riparian nations. Five basins – the Congo, the Niger, the Nile, the Rhine and the Zambezi – are shared between 9 and 11 countries. The river that crosses the most countries is the Danube, which crosses the territory of 18 nations (United Nations, 2014). At least thirty-three countries depend on other countries for more than 50% of their renewable water resources. These countries include: Argentina, Azerbaijan, Bahrain, Bangladesh, Benin, Bolivia, Botswana and Cambodia.,...