Here, after flowing out of the Nanjing Pass , the Yangtze River slows down and widens from 300 m to about 2,200 m at the dam site. Two small islands, Gezhouba and Xiba, have divided the river into three channels. This is where the Gezhouba Project was built.

Construction started on December 30 th , 1970 and ended on December 10 th ,1988. It boasts a generating capacity of 2.71 GW and also has three ship locks, two power stations that generate 14,100 GWh of electricity annually, 27 gates of the spillway, and the dam on both banks. The dam is 2,595 m long with a maximum height of 47m . The reservoir has a total volume of 1.58 km 3.

The navigation lock No. 2 on the third channel was, when built, among the 100 largest in the world. The lock chamber is 280 m long and 34 m wide, with a minimum draft of 5 m at the sill. It provides passage for ships of up to 10.000 tons.

The process of passing the dam itself is an interesting experience. Since the water level on one side of the dam is 30m higher than that on the other side, the boat has to ascend to the other side of the dam to continue its voyage.