How did the Three Gorges Dam affect navigation to Yichang and Chongqing?

The Three Gorges Dam has significantly transformed navigation on the Yangtze River between Yichang and Chongqing.

Prior to the dam's completion, the river in this region was characterized by violent currents and extreme water level fluctuations, which often necessitated the transshipment of goods onto different vessels at Yichang. The construction of the dam created an immense deepwater reservoir that extends approximately 600 km (375 miles) upstream, effectively regulating the river's flow and reducing these dangerous fluctuations.12

Navigation past the dam is now facilitated by a complex system of five-tier ship locks, which allow vessels of up to 10,000 tons to pass, and a large ship lift that enables vessels of up to 3,000 tons to bypass the locks more quickly. These improvements allow oceangoing freighters to travel 2,250 km (1,400 miles) inland from Shanghai all the way to Chongqing, significantly enhancing inland trade connectivity.23