Chao Lake, or Chao Hu, , is a lake located at the juncture of Chaohu and Hefei cities in Anhui Province, China. It is the largest lake in Anhui and one of the five largest freshwater lakes in China. Mushan Island is situated within the lake. About 5 million people live near the lake, and use it for irrigation, transportation and fishing. Heavy use of the lake in recent years has led to eutrophication and silting. Due to China's rapid economic growth, the lake is now one of China's most polluted lakes.