In ancient China, hydraulic engineering was highly developed, and engineers constructed massive canals with levees and dams to channel the flow of water for irrigation, as well as locks to allow ships to pass through. Sunshu Ao is considered the first Chinese hydraulic engineer. Another important Hydraulic Engineer in China, Ximen Bao was credited of starting the practice of large scale canal irrigation during the Warring States period (481 BC-221 BC), even today hydraulic engineers remain a respectable position in China. Before becoming General Secretary of the Communist Party of China in 2002, Hu Jintao was a hydraulic engineer and holds an engineering degree from Tsinghua University