More than half of the world’s major rivers are polluted or are going dry, according to the World Commission on Water for the 21st Century, which is meeting at The Hague, Netherlands. The degradation of waterways and surrounding river basins threatens the health and livelihoods of people who depend on rivers for drinking water, irrigation, and industrial uses. China’s Yellow River, which runs through the country’s most important agricultural region, is severely polluted and ran dry in its lower reaches 226 days in 1997. More than 90 percent of the natural flow of Africa’s Nile River, the longest waterway in the world, is used for irrigation or is lost through evaporation, primarily from reservoirs, and what reaches the Mediterranean Sea is heavily polluted, the commission found.