How did they learn to build dams and channels?

Ancient civilizations learned to build dams and channels through trial and error, observing natural water flow patterns and the behavior of river systems. Knowledge was passed down through generations, with early engineers and laborers experimenting with materials like earth, stone, and timber to create effective structures. They also relied on practical experience and local geography to develop techniques for controlling water for irrigation, flood management, and navigation. Over time, this knowledge evolved into more sophisticated engineering practices.