People fishing along the bank of the Yellow River as the Sanmenxia Dam discharges flood waters downstream in Pinglu, Shanxi province.

The fish are forced to the surface by the rushing water, attracting those who live nearby to rush to catch them.

The dam was completed in 1960, the first major water control project on the world's sixth-longest river.

Though its construction displaced some 400,000 people, it provided flood and irrigation control as well as hydroelectric power, among other benefits.

But it drew criticism when sediment rapidly accumulated and reduced the capacity of the reservoir, necessitating more renovations to remove the sediment.

Over the years, China's mega-dam projects have drawn flak for their ecological destructiveness and their impact on millions of human lives.

Now, Beijing has submitted its environmental goals for 2030 ahead of the Paris climate summit in December, pledging to cut carbon emissions by committing to non-fossil fuels.

Non-governmental groups such as International Rivers foresee a surge in the construction of more hydropower dams, particularly in the south-west, central and far western parts of the country, where there are still free-flowing rivers.