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 Grand Canal is a system of interconnected canals linking various major rivers in North and East China, serving as an important waterborne transport infrastructure between the north and the south during Medieval and premodern China. It is the longest artificial waterway in the world and a UNESCO World Heritage Site.