River damming can damage downstream environments by retaining sediments. Sediment
problems are always heavily emphasized in discussions of the Three Gorges Project. When
the TGD started operating in 2003, the Yangtze downstream entered a stage of sediment
reduction. During the first 2 years of impoundment (2003–2004), sediment discharge at
Yichang (first station downstream the dam) decreased by 164 million tons (Xu et al. 2006).