According to Xinhua News Agency Yichang Branch on October 17, only 5 meters are left in a new round of 175-meter experimental water storage in the TGR (Three Gorges Reservoir). It is learnt from China Three Gorges Corporation that, during ten-year water storage of the reservoir, average annual sediment load entering the reservoir reduces more than 60 percent comparing with the initial design value, and average annual sediment volume accounts for 42 percent of predicted value of the demonstrate stage, showing that the state of the sediment is obviously better than the expectation.

　　According to the Three Gorges Group, the monitoring data shows that, since the Three Gorges Project began to store water in 2003, average annual sediment load entering the reservoir reaches 190 million tons which reduces 62.7 percent of sediment comparing with initial design value of 509 million tons because of the sediment retaining of reservoirs on the upper reaches of the Yangtze River, conservation of water and soil, climate change and sand excavation in the Yangtze River. With upstream reservoirs being put into operation gradually, the average annual sediment load entering the reservoir will further get reduction.

　　For hydropower engineering, sediment accumulation is a vital problem. After the practice of the Gezhouba Reservoir and the TGR, China has got an experience which is “restoring clear and releasing muddy water”- the reservoir releases water when there is sediment and stores when no sediment to solve the problem about sediment management that is a worldwide challenge. It proves that the mode can effectively reduce the sediment accumulation in the reservoir.

　　(Reporter Liu Ziling, Liang Jianqiang)