When was the first major river diversion project carried out on the Yellow River?

Ancient Chinese engineers were already trying to control the Yellow River more than 2,200 years ago. A major early diversion project is traditionally dated to about 246 BCE, during the Qin dynasty, when large-scale river management was used to reduce flooding and redirect water. The Yellow River's shifting course made it one of the most difficult rivers on Earth to control. Over later centuries, many dynasties built dikes, canals, and levees to manage the river's destructive floods.