Lingqu is composed of spout, scale, south canal, north canal, drainage balance and steep gate. It is scientifically designed and beautifully built. The spout divides the water in the Xiangjiang River into three parts, three of which flow into the Lijiang River south and seven into the Xiangjiang River north, connecting the Yangtze River and the Pearl River. Since the Qin Dynasty, it has become a transportation hub between the Central Plains and Lingnan, and played an important role in the process of Qin Shihuang's unification of China.
Nanbeiqu
The South Canal of Lingqu is an artificial canal formed by trimming and connecting the original natural small rivers, with a total length of 33.25 kilometers and winding around the mountains, which is the main channel for Xiangjiang River to enter the river. There is a 3.7-kilometer-long Qin Long levee between it and the old Xiangjiang River. It is made of bluestone, which can prevent the water from flowing back to the Xiangjiang River from the South Canal and prevent the flood from hitting the South Canal.
Lingqu North Canal was built to solve the navigation problem. The scale cut off the Xiangjiang River, so ships could not pass, so a North Canal parallel to the old Xiangjiang River was dug. Because the river channel is only 4 kilometers, and the water level difference is large and the flow speed is fast, three "S"-shaped bends are built to let the canal water flow into the Xiangjiang River in a roundabout way.