The Huai River, formerly romanized as the Hwai, is a major river in China. It is located about midway between the Yellow River and Yangtze, the two longest rivers and largest drainage basins in China, and like them runs from west to east. Historically draining directly into the Yellow Sea, floods have changed the course of the river such that it now primarily discharges into the Yangtze. The Huai is notoriously vulnerable to flooding.

The Yellow River is the second-longest river in China, after the Yangtze River, and the sixth-longest river system on Earth at the estimated length of 5,464 km (3,395 mi). Originating at an elevation above 15,000 feet in the Bayan Har Mountains, it empties into the Bohai Sea. The Yellow River basin was the birthplace of ancient Chinese civilization. Its yellow sediments are carried downstream from the Loess Plateau. The river experiences frequent devastating floods and course changes produced by the continual elevation of the river bed, sometimes above the level of its surrounding farm fields.