Why has sediment buildup reduced the generating capacity of the Sanmen Gorge Dam?

The Sanmen Gorge Dam has experienced a significant reduction in its power-generating capacity primarily due to the Yellow River's exceptionally high sediment load.12

The river carries the highest concentration of silt of any river in the world, much of which consists of loose loess soil that is easily eroded. Once the dam was completed, this massive volume of sediment began to accumulate rapidly within the Sanmenxia Reservoir. This heavy siltation reduced the reservoir's overall capacity and functional effectiveness.213

While reconstruction projects were undertaken in 1965 and 1970 to improve the dam's discharge capacity for both floodwater and silt, the ongoing, enormous accumulation of sediment has continued to limit the facility's ability to generate electricity, restricting its output to only a fraction of its total potential capacity.1